You are correct and I have updated my text description accordingly. iMacs that did NOT have the tapered edge were sold in 2012 up through October 2012 and so those non-tapered iMacs with removable video cards ARE covered by the bake, but technically they would be "2011" models not 2012 models. I should have made that clearer in my video. Thank you for clarifying that very important point. I have pinned your comment so it would perpetually be at the top of the comments section for all to see.
I baked the card in my iMac 2010 27 inch yesterday (200˚C, 10 min). This is my second experience. Before baking, the the screen was full of lines. Now, at least at this point, it works perfectly. I did my first card 3 years ago after watching your videos. And this time, I also checked your videos again to make sure every step is OK. Thank you so much!
It is unfortunate that the bake doesn’t last forever. But I’m certainly pleased to hear that your second bake was a success! I hope you get at least another a few years of use out of it! Best wishes.
For me it ‘s been 1 year now ... using your video and doing the bake for my late 2009 iMac 27 ... and it’s still working 🤗. Thanks again for your great videos 👍🏻.
JDW, Thanks for your videos (I watched them all). This works! I just baked my 2011 27" iMac's AMD 6970m GPU and it works again. I simply followed examples shown in several of the youtube videos including yours. I have never done anything like this before. This was the first time I opened up my iMac. While it seems intimidating at first, I did it. The hardest part was reconnecting the power cables behind the Logic Board and from the LCD panel to Logic Board. I put a sequential numbered piece of electrical tape on all of the wires and it went together smoothly. Baked at 400F for 10 minutes. Took about 3 hours to fix. My thanks go to all of the TH-camrs who filmed the process and also to those users who posted their encouraging success stories too.
This video deserves more exposure. I've been searching for information about this for quite a while, and it's only today that this video shows up, and it condenses a lot of the info needed to try to fix the video issues, wish I found this sooner.
Hi JDW, many thanks from the Netherlands for your video. My 2009 iMac i7 broke down and after reviewing your video's, I was able to repair my iMac. At almost no cost! I was really thrilled when I started up for the first time after the baking procedure and to see that my iMac was alive again! Again, many thanks!
I just baked my graphics card for the 3rd time 2 days for 15 min. At 405 degrees ( I suspect our oven isn’t as hot as as it should be). K5 pro (the goopy stuff) and Kryonaut on the chip. It never ceases to amaze me that this works but I figure I have nothing to loose! The first time lasted a few months, 8 min, 392 degrees. The second time was 15 min. 400 degrees lasting 6 months. I think the Greece was the problem MK ?something. I think that it wasn’t goopy enough to fill the gap on the other small chips. I think it was your video that prompted me to buy the K5 pro otherwise I was looking at buying pads. Thank you!
Hi, Sandy. Wow, 3 bakes! Well, I am sorry to hear that because I know how much time each of those took you! 405°F is 207°C which is roughly the right temperature, assuming your oven really is that temperature. You can check it with a turkey thermometer to be sure. So you used MK-4 on both the GPU and memory chips after your first 2 bakes? If so, that would explain it. MK-4 is great for the GPU but not for the memory chips which require thermal pads. They require the pads (or a thermal pad replacement like K5 Pro) because the gap between the top of those memory chips and the heatsink is quite big. I believe that led to my 1st bake lasting only 4 months. So your case lends more support to that theory. Anyway, I'm hoping you'll get 2.5 years+ like me on this latest bake! Best wishes in 2020!
First, thankyou for an excellent and detailed video. I also had the same issue (100's of artefacts) with my iMAC mid 2011 27" i7. I baked my card and applied the K4 and K5 paste as per your second bake video. It's only been two weeks but in this time no issues. Indeed, having gained the confidence to take my iMAC apart I have installed a 120GB SSD as my system disk (including the recovery partition) and keeping the 1TB HD as my data disk.
Thanks for these videos JDW. Tried this on my 2009 iMac back in Sept 2018 and has worked perfectly for the last 18 months till last Sunday. Redid the bake on Monday and so far working perfectly again, hopefully at least for another 18mths. For anyone trying this be super careful of the first ribbon cable in the top left with the blue backing, the one JDW had to replace in the video. Its very fragile and even if you are careful not to tug on it as you open the screen it clearly is not designed to be handled frequently either and will start to de laminate on the end. Cheap to replace but good to avoid the hassle if you only have the one computer.
@@JDW- Hi, as I didn't want to go to too much trouble over an old machine I just purchased what was available locally which was the Duratech Nano Diamond thermal compound. Interestingly the heat sink gap was very narrow compared to yours (maybe 1/2 a millimetre) so didn't need to use much paste at all.
There is no better Video of disassembly in all you tube of the Imac 27 it is the BEST TUTORIAL, I also believe that the paste that you recommended from Greece it is the best, I think that is the key when you bake this card, I have 2 imac 27 2011 Imac 27 i7 3.4GHz iMac with an AMD Radeon HD 6970M 2048 MB has been bake almost 2 years ago and still working My wife Imac same specs just last 1 year and a half bake again and it is working, this is how I do it: I preheated the oven and baked the graphics card for about 9 minutes @ ~380-390°F (about 200°C). I then let the card cool down for about 30 minutes. Mr. Rossman is the best on the field and it is right but nobody it is perfect. Happy New year. Cesar.
I am humbled by your very kind words, thank you. Thank you also for sharing your multiple success stories, as well as for providing details on how you do the bake. Happy new year!
Just did my graphic card back an hour ago and it was a success. My 2009 imac symptoms was, when power up, it was stucked in boot chimes over and over again. LED 1 LED 2 and LED all lighted up except LED 4. Decided to do the "bake" after seeing success online. after baking for 7 mins at 200 degree C. installed every back, the imac boot up like a charm!
Hello JDW, hope you’re well. I wanted to thank you for your videos on reviving these iMacs. Mine is a late 2009 i5, 2.66. I’m just getting the tools to carry out this procedure. I’ve not done this type of thing before but am looking forward to bringing my iMac back to life. I think the main things is keeping everything labelled (as you show in your 1st video). It seems slightly daunting but I think I will achieve success with your guidance. I’ll let you know how I get on. Thanks again, Jerome
If you follow my video and if you have read through the text description under my video, you’ll do fine. Just keep it slow and stay calm. When you take out the display, just make sure it doesn’t fall forward, so you don’t break any of those ribbon cables. I read and reply to every single comment under all my videos, and I can tell you that the vast majority of people who try the big or successful. As long as you use a good thermal paste, your bake should last a long time. Best of luck to you, and be sure to let me know how it went.
Thanks for your reply. That’s great advice and I will follow your directions carefully. I am just going through the videos again to reinforce what I’ve learned so far. Thanks again and I’ll. let you know when I’ve got the iMac back in action.
Thank you for your very kind words, JJ. More subscribers would be a tremendous blessing indeed in light of my day-job/salary situation. Things were bad enough before Corona hit, but now it's just awful. I enjoy making quality videos that help people, and I wish I could support my family doing such work. Anyway, I am currently shooting and editing a new video about the Macintosh 128k~Plus Analog Board. Stay tuned!
I did a bake about 2 years ago on a mid-2011 iMac graphics card.... and it bought the unit back to life. I was sceptical before trying it but felt I had little to lose by giving it a try.... I was surprised but also delighted that it worked....
It was..... but the iMac went belly-up a couple of days ago. At first, I thought it was a drive problem as the symptoms didn’t match the first time the GPU played up..... but, eventually, I narrowed it down so the GPU seemed like the most likely issue.... and that’s why I started to re-watch some of the TH-cam stuff to refresh my memory of what was involved. Anyway, took it apart today, baked the card and, yay!, it’s solved it again. The machine is now working again..... :-)
@@JohnWaldenDDM Well, it is a positive sign if your first bake lasted 2 years. My first bake lasted only 4 months, although that was likely due to my bad thermal paste job. My 2nd bake lasted 2 years and 9 months. My 3rd and 4th bakes lasted only a week each. So if your 2nd bake lasts longer than a week, then I would say it probably will last for a considerable amount of time. Please keep me informed on how it does over time!
Used your video to repair my 24-inch '08 iMac just two days ago. Different computers, same idea though. Baked the video card and it has been working since. Much appreciated!!
@@JDW- an unfortunate update: the system is starting to have issues again when powering on from sleeping. Hoping that I could maybe get it working once and for all with another bake like you did. Can't really complain since I got the machine for free and gained a ton of experience out of it. Guess I'll get something a bit newer!
@@cassadagaa What kind of thermal paste did you use? Did you fully clean off the stock thermal paste before your bake? What was the temperature and time of your bake? My 1st bake lasted only 4 months and I strongly suspect it was due to the fact (1) I didn't clean off the stock thermal pads on the memory chips and instead added new paste atop those, and (2) I used Arctic Silver V on the GPU which had some overspill. Arctic Silver V is capacitive, so any overspill onto surrounding components could cause problems. After my 2nd bake, I used K4 Pro on the GPU (which is not electrically conductive or capacitive) and I used K5 Pro on the memory chips, since it is designed to work well in that application where there is a large gap between the top of the memory chips and the bottom of the heatsink. Maybe you could say it was a second bake that also helped too, I don't know. All I know is that I have gotten 2.5 years of use out of that 2nd bake and thermal paste combo, and the machine is still going strong. I hope this info helps you decide what to do.
@@JDW- I used the same paste you did (Arctic Silver V) but I did something pretty stupid: I decided to just leave some of the stock paste on the memory chips and not even bother putting any new paste on. I decided to give it another go in oven.. Unfortunately, I think I killed it. Only a white screen on boot up and nothing more. Decided to cave in and get an ATI 2600 HD Radeon for it (since these 8800 Nvidia cards are notorious for failure). Some good lessons learned nonethless.. I must of taken apart my iMac 10 times during this whole procedure! Thank you again for the very helpful video!
My 2011 27" had its 6970 fail in December 2021. I got it fixed in time to start 2022 and start a new chapter in its life. At this moment, it's been doing fine for 7 months. At the time of failure, it fell hard and fast, working great all along then going kind of frizzy and straight into the shutdowns and boot loops. Down for the count. I cleaned the interior of the machine and because it's a 2011, it required the removal of the entire logic board. I replaced the battery (a regular lithium 3v will do because I use SSDs that don't generate the temps that rotary HDDs do). Removed and cleaned the CPU while in there, and repasted before putting it back. Reading and viewing all kinds of opinions about oven temps and bake times, I put the card in about midway through the preheat, left it in for 10 minutes at 390F, and then opened the door to bleed heat for a bit after that timed period, then let it cool inside the closed oven, and opened up again to finally let it get to room temperature. There was enough difference of opinion that trying not to shock things into 'too hot' and cooling too fast seemed a sensible way to go. I didn't have 90% alcohol but with 70% I did a few passes of shining things up and letting the parts dry well. Dry climate here in the winter, so maybe that affected things favorably. Custom cut thermal pads to fit the VRAM chips. Some required stacked pads to fill the gap consistently, using different thickness sheets. The GPU die itself got Arctic Fox paste. Took my time rehearsing the fit before committing to the paste and pads. Because this was a 'wait and see' procedure, on reassembly I left out the ODD entirely (I actually had an SSD adapter there), and a moulded piece of plastic that divides the ODD area from the HDD area. It seemed superfluous. I also just electrical taped the SSD into place. All told, there is much more contiguous space inside for airflow. The lack of ODD means the right side fan can target the GPU heat sink directly. There is a bit of physical noise. I guess the plastic piece was a bit of a dampener. As of now, I won't mess with a working unit but I guess I'd put it back in. Then goes the fun part hoping to get all the parts back together and get the three LED signal at startup (indicating the GPU is being engaged). Reset the SMC and NVRAM on starting up. Good to go. Yay! The only thing I have seen not work right does not particularly affect my actual usage. Geekbench testing must have pushed things too far. In a series of 4 tests over a few days, there was a predictable delay in the test speed, then a spontaneous blackout and a return to the login screen (but with lo fi display res), and then on logging it it would black out again for a while, then return to the full res login screen where I could log in and go on with things. It did this predictably in High Sierra. I've been using Opencore Legacy Patcher for a while and this spring I got Big Sur going on this machine, still with the baked card. Doing the Geekbench test takes way too long BUT it does not do any of the other oddness with blackouts and login screens. But again, GB is an unusual case and is not my daily usage. Otherwise, the machine went from being a retired studio machine last year to becoming a general daily driver for me to do all the web stuff, TH-cam, and all that kind of general use stuff. With OCLP and Big Sur it doesn't feel old at all. Seven months so far with the baked card. I have a different iMac with a K2100m. It has been going for nearly two years now. Has four different OSes on it including Monterey 12.4--presently the last of the line if the Kepler cards can't be made to work with OCLP's help. But between replacement GPU and OCLP, that is a huge extension of the old iMac's life.
Nice video. I can confirm the "oven bake" works very well: baked a AMD Radeon HD6970 card in my pre-heated oven at 205C for 10 minutes and turn down the temp and open the oven to let it cool down, from a mid-2011 iMac 27" 4 months ago and it is still working well. I also use Mac Fan Control with sensors controlling individual fans. The GPU die temp is at around 62C and GPU heatsink temp at 52C (Arctic Silver 5) for normal use (not playing any game).
Just did my first bake on a 2009 iMac. Seems to be working Ok. Thank you for your videos. It was a great help! I didn't take the mother board off, managed to get it off but putting it back was a little tricky. I used the K5 paste for the chips like you recommended and MX-4 thermal compound on the GPU. It's a great machine still powerful enough to do my high-end retouching.
Thank you for your video it helped me complete my first video card bake yesterday on my ageing 2011 27” iMac. Local repair shops told me to junk the iMac for this was my second video card. My first one was replaced by an Apple authorised repair shop under warranty, after the apple store would not fix it for I had added a second SSD, voiding the warranty. I think that if it fails and can not be repaired, I may just gut the iMac and turn it into a monitor.
Thank you for making time to share your success story, Caleb. The bake doesn't last forever, but you should, like me, be able to get at least 2 good bakes out of it before the video card needs to be replaced. How long each bake lasts varies wildly. My first bake lasted only 4 months, most likely due to my inferior thermal paste job (as shown in my 1st bake video). My 2nd Bake lasted 2 years and 9 months. Then my 3rd and 4th bakes failed. I think the 2 years and 9 months was worth the effort of the bake. And although I paid a rather high price for a replacement video card and heatsink (6970M), it is much cheaper than a new iMac, especially when you consider that here in Japan you have to pay to dispose of items. Even Apple Japan doesn't make it's return policy clear. In most cases, you must pay a whopping $50 fee to get rid of old TVs, computers, appliances, etc.
You explain everything very well and i'm getting all my ducks in a row to try the bake. Just a quick query: When I put my iMac mid-2011 27" into target disk mode (cause of white screen and disk recovery only gets as far as spinning globe with triangle and exclamation point) and check out Disk Utility on a second thunderbolted mac, my HD2 shows up OK in the sidebar (which is where I keep all my data) but my main HD is greyed out and says disk4s2 and won't mount. Would this have anything to do with the GPU and do you feel my iMac and all its disks could come back to proper life after a bake? Thanks again!
You should be able to access data on your drive normally after the bake. Sometimes there are booting issues after that bake that have to do with data corruption on the hard drive, but in that case, after the bake, you would just need to attach an external drive or bootable thumb drive or boot from Recovery and run Disk Utility to fix those problems. The bake should restore your iMac to working condition again so you can diagnose your drive in the normal manner and even use Target Disk Mode normally too. Please let me know how it goes after your bake.
I read and reply to all comments, and in every single case to date, the root cause for the post-bake black screen is either a cable forgotten to be reconnected or a snapped cable. This unfortunately means you will need to reopen your iMac, but it also means the likelihood of your being able to fix the problem by rechecking all cables is very high. The wide ribbon cable in the middle is especially hard to snap into place correctly during reassembly, so pay close attention to that.
@@JDW- Okay, I probably broke that ribbon cable, it doesn't fit well and unplugs everytime try to attach other cars. After like 2 hours I somehow managed to attach it and now the loud fans stooped - just black screen. Can i replace the cable myself?
@@why4213 I'm sorry to hear that. I accidentally broken the narrow ribbon cable in the upper left during disassembly for my 2nd bake: th-cam.com/video/6BJGLFCigdA/w-d-xo.html I decided to buy both ribbon cables and replace them (Amazon affiliate links below). If your narrow ribbon cable is fine, then you would only need to replace the wide one. Just made sure it is the cable and not the mating connector on the motherboard that is broken. • BIG cable: amzn.to/32Ygv7s • SMALL cable: amzn.to/33ZEvX4
@why421 If there is any kind of major issue with the video card, it is possible the screen will be completely dark, external displays will not work, and you would also not be able to use Target Display Mode.The ribbon cables should impact only the internal LCD though. The bake works for almost everyone who does it properly, on the first time it's tried, although that doesn't mean an automatic guarantee it will resurrect all video cards. So cards are just too far gone to be baked back to life. Let's do some troubleshooting... 1. Are you 100% certain your iMac's video card has never been baked before? (If you're the original owner, you can know that.) If it has been baked before, it's possible additional bakes will not work. 2. Did you clean off all the old thermal paste on the card prior to baking it? In theory, that shouldn't affect the bakes work on fixing the GPU chip, but it's important to clean off all the paste before the bake. 3. Did you use a turkey thermometer or similar oven-safe thermometer to confirm the temperature of your oven is accurate and stable? This is actually an important step, since some people have reported very low temperatures, while others have reported temperatures so high components became desoldered. 4. Did you bake at the designated 200°F or 392°F (400°F is acceptable) for between 7-11 minutes? 5. Did you apply 2 different types of new or almost new thermal paste to the GPU and memory chips after your bake? Note that regular GPU/CPU paste won't work on the memory chips because there's a gap between them and the heatsink. That's why you must use either thermal pads or K5 Pro. I recommend K5 Pro because you then don't need to worry about knowing thermal pad thickness, which can be tricky. 6. Did you follow my 1st Bake video where I removed the entire motherboard, or did you follow my 2nd Bake video where I remove only the video card? I ask because if you removed the motherboard, there are many connectors that you would have disconnected, so reconfirming all those connections is very important. It could be that some connectors look connected at first glance but in fact are only making an intermittent connection.
I've done it and it worked for 4 years, I'm going to do it again tonight for another 4 years. I own 5 Imacs of various years and they bulletproof except for fusion drives, standard hard drives and this video card problem.
4 years! My friend, I believe you are the record holder. I read and reply to every comment, and thus far, you are the first person to report back with a 4-year bake life span. I love hearing such stories though because it's yet another nail in the coffin for the naysayers who falsely claim the bake either doesn't work or won't last. With that said, in my own experience, there is a limit to how many times you can bake your 4850 card, assuming that is the one you baked. Hopefully your next bake works and lasts another 4 years!
It varies quite a lot. One person recently told me he got 5 years from his first bake. I got only 4 months from my 1st bake but then 2 years and 9 months from my second bake. But once the bake stops working, you only get a week or less, and then it's time to replace the card.
Thank you for making time to let me know your success story, Dan. Feel free to write back in a few months with an update. Hopefully your machine will get the same longevity as my 2nd bake. Still going strong after 2 years and 7 months!
Thank you for your sharing. It's working. I just fixed my 21.5" IMAC 2010. I contacted 2 local shops for repairing. They both said I needed to replace the display card. Luckily, I found your page and it is working now. I have a question. Can we skip the bake and replace the cooling paste?
Unfortunately, you cannot skip the bake. The reason why is because the root problem is not the thermal paste but instead a problem inside the GPU chip. Heating the chip fixes the problems inside it. Of course, after your bake is finished, you need to apply the correct thermal paste before putting the card back in your machine, otherwise all the work you did on that bake will not last very long. I strongly recommend K4 & K5 Pro.
@@leninmx Meaning, your display is dark and you do not know if it really is the backlight or if it is the video card again, right? If only the backlight is dead, the iMac should still boot, and you should be able to perform some keyboard action that will make an audible sound, like pressing several times on the F12 volume-up key. If you hear no sound or otherwise have no indication of a successful boot, then it is surely the video card. Did you get a black screen prior to your bake?
@@leninmx If you never had issues with the backlight prior to disassembling your iMac, then it is highly likely you did not secure one of the connectors well when you reassembled it. You may need to check the dual ribbon cable connector shown at 7:58 in my 1st bake video here: th-cam.com/video/v1DXBLkiqFM/w-d-xo.html
I have a 2008 - 24" - 3.06ghz - with the defective Nvidia (my understanding was that this was the main problem as the Nvdia's were inferior) - My first bake worked great and lasted about a year but with very light use. I used K4 and K5 paste. I'm about to open her up and repeat. I'll be curious to see the condition of the paste and based on what you say - perhaps I should use more to 'fill the gaps' - If successful I will also add the Fan app you recommend. I remember when I originally had the problem, I could get a few more hours before the screen went, just by blowing a fan across the back of the machine. I'll let you know what I find and how it goes... thx
Charles, I’m very sorry to hear your bake only lasted one year. My first bake only lasted 4 months, but I attribute that failure to my use of old thermal paste and the fact I did not clean off all the old paste from the memory chips. Even so, your case is the first I’ve heard of a bake lasting only one year while also using K4 and K5 Pro thermal paste. It seems you did not use a fan control app during that one year after your bake, so I’m curious if my use of that app has contributed to the long duration of my second bake (which is still going strong). But I also wonder if it could be due to my having baked the card twice. I’m not sure. In any case, I have my fan control app set to activate all the iMac fans at a constant 2000rpm. I hope this information helps.
@@TH-vb6iw Thank you for letting me know about the dead Macs Fan Control link. I just fixed it. The following version is what you need: crystalidea.com/downloads/legacy/macsfancontrol.zip
@@JDW- OK, I'm 2 for 2. Got her up 'n running again - (used more paste) Downloaded Macs Fan onto my 2012 Mini to then move over to the iMac. I see it is set on 'auto'. Once on the iMac, what next ?(settings?) Can you help me with the settings - and if I leave it on the Mini (on auto) will that change anything on the Mini (which doesn't have heat problems). thx C
@@TH-vb6iw To the right of "Auto" is "Custom..." Click "Custom..." Set a Constant RPM value that is higher than the typical. On my 2009 iMac, I chose 2000rpm, which is a fair amount higher than normal, but not max. Max would be too loud. Make it as high as your ears can endure, to ensure better cooling.
Although there are ways to get more recent versions of macOS to run on that model, and even though you technically could get even Apple’s Metal to work by way of a flashed Nvidia graphics card, you still would not be able to update the CPU, which would hinder performance. In other words, High Sierra gives you the best performance overall on that older Mac, and that is why I have remained content to use it to this day. High Sierra is a rock solid OS for Intel Macs. To get the most out of Big Sur or Monterey, you really would need an M1 Mac.
hi, me again - I just came into an early 2009 20" iMac with a Radeon 2600 Pro - working - but vertical lines on the screen are distracting - do you know if this one is heatable ?
I cannot speak from personal experience because I don’t own one of those, but I have received comments from people who own 2008 iMacs, and they reported to me that they used the bake with success. I looked up a photo of the Radeon 2600 Pro and I don’t see any electrolytic capacitors on it, which means the bake would be safe.The bake just might work for you.
@@JDW- I've never opened the 20" but I assume it's not too much different from my 24" (except) Radeon instead of nvidia). I'll let you know how it goes - if it works I have someone waiting for me to do another one...
I tried it on a iMac mid-2007 20 inch. I baked at 275F for 10 minutes. Although it didn't work I have a question... you used K5 and K4 thermal paste. Why not just use K5 since it has a higher thermal conductivity? Thanks for the videos.
You are the first person to report having baked the video card from a 2007 model. Until now, the oldest machine reported to me was a 2008. Therefore, I cannot say if the bake works on video cards from 2007 machines. Your experience indicates it is not possible. K4 Pro has higher thermal conductivity than K5 Pro because K4 Pro is made for use on a GPU or CPU whereas K5 Pro is a thermal pad replacement. That is why you would never use K5 Pro on a CPU or GPU. K5 Pro is made to fill a gap between chips and a heatsink.
@@JDW- thanks. I bought a used video card on eBay and the machine is working now. But I just used what ever thermal paste was left when I put it back together. The GPU had a grey paste and the memory chips had a white paste. I will order some paste from Amazon but was wondering if I could just buy one kind of paste instead of two. Thanks again.
@@brucemerrill7821 I left the stock Apple thermal pads (on the memory chips) intact after my 1st bake. That was a mistake on my part because that bake lasted only 4 months. After my 2nd bake, I did a 100% thorough job of cleaning off ALL the old thermal paste. I then used K4 Pro on the GPU and K5 Pro on the memory chips. That 2nd bake lasted 2 years and 9 months. So you definitely want to clean off all the old thermal paste after any video card bake.
@@JDW- about removing the videocard, the part which is connected to the motherboard: I found it difficult to remove that small cable, so I just removed the actual videocard from that part, so I didn't have to struggle with the cable :)
You only mentioned having used one type of thermal paste - Cooler Master E2. Did you clean off all the thermal paste including the thermal pads that were on each memory chip? You cannot use regular thermal paste on those memory chips. You either have to use thermal pads or a thermal pad replacement like I did - K5 Pro.
Ok, green lines white screen and now just white screen partial apple line then white. No success in any recovery keyboard option. Imac 27 2011 use less...so I ordered the Geeece grease :) and like you an older dad I am going to give it a go. It looked like way to muck grease until I saw a gap...makes sense now. I will follow up in a week since I am furloughed with this Covid thing I have plenty of time. Thank you for your excellent video and speaking ability.
The two greases from Greece are key! :-) Since my video collection on this topic is extensive, there's not much more I can say except to use a turkey thermometer to verify your oven temperature matches the dial setting. A small number of folks have told me in the comments that they experienced desoldered components. In every case, it seems their oven was on the fritz. It you put a turkey thermometer inside during your pre-heating time, you'll be able to confirm the inside temperature is correct with any inconvenience. Also remember to make the little foil feet, try to make the video card rest level, and bake it with the component side up. Aside from that, it's patience and time. Let me know how your bake goes!
Great video and very informative. Very measured but persuasive. I was a skeptic of GPU baking but there seems to be a mounting body of evidence that this is an effective technique. Thanks a lot.
Thank you, Ian. As an electrical engineer I must admit the bake is highly unconventional and not something you would expect to work. And while I cannot say precisely what is damaged inside the GPU chip, heating it absolutely fixes the problem. Whether it be an oven or heat gun, it will work for you if you have a 2009 to 2011 iMac. Just make sure you use the thermal paste that I recommend. Best wishes!
Thanks! I don’t have one to fix, I’m just interested in the topic. If I get some free time I might see if I can pick up an old 2009 iMac and breath new life into it. I have the ram and an SSD hanging around so it could be an interesting project.
If you find one on eBay with a description that says the screen won’t display anything or the screen is all white or there are screen artifacts or it randomly freezes, chances are it’s the video card. And in that case, the price will probably be very low so you could get a really good deal. If you do get an iMac like that, and if you do the bake,, be sure to comment back with your experience. Best wishes!
Inside the power supply unit, yes, of course. But fluid-filled electrolytic take many years to go bad. Maybe around 2030 you can start thinking about that. :-) But the video card in the 2015 5K iMac is totally different from the 2009 to 2011 model iMacs, so you don't have to worry about that either.
You're right. If you have a 9 year old iMac with a failing GPU, what do you have to loose trying this option? It can't get any worse than it is. It took me half a day work to do this repair and my iMac 2011 was up and running again. Compare that to bringing it to a repair shop, which takes a couple of days and (considering the price of a new GPU card) a considerable amount of money. If it fails again, I'll just try it again. As a note. I twice had my HD replaced by Apple Repair, both times it failed exactly at 3 years lifetime. Every time it costed weeks of waiting and a lot of money. The 3rd time I replaced it myself, this time with a SSD. I think it is now over 3 years and not the slightest show of possible failure, yet. The job was done in less than 2 hours and the cost was less than 25% of what Apple charged me before. My take on it. Apple has good products, but way too expensive and a terrible service. After it all fails permanently, it is back to the PC again and likely turn to Linux (Windows sucks!).
Thank you for sharing. Your SSD probably won't fail anytime soon. My SSD has being going strong nearly 5 years. It draws less power and puts off less heat than the stock hard drive, which means the internal temperature of the iMac will be a tad cool. I think it will make the iMac last even longer. Once you swap out the hard drive for an SSD, the weakest point of the machine is the video card, even if you swap out for a brand new stock card. Some people have tried some newer MFM cards for PCs, but they require flashing a a lot of fiddly work that most people (myself included) don't want to deal with. They might last longer though. Not sure. Even so, you would be out the cost of the card in that case, and the bake is cheaper. The lowest cost fix is the best fix for these old iMacs in my book.
@@JDW- I agree. It is hilarious in a way that for half a day tinkering and 10 minutes in the oven, you can save yourself hundreds of dollars. Not to mention that the life of the machine is extended for at least a couple of years. Why buy a new iMac for thousands of dollars if this one can do the task too? 80% of the people can work very efficiently with these old iMacs. Maybe upgrade the memory and a SSD in it, and voila! another couple of years fun with Apples.
@@paulvandriel2344 Absolutely. The down side is that folks with the 2012 and newer iMacs cannot easily open them like the 2011 and earlier. The good news is that the newest iMacs seem to have resolved the video card issues. I have a late 2015 5K iMac at the office and it's been going strong nearly 5 years. It has an internal SSD only, not a spinning HDD, inside which makes it fast, quiet and cool. It did cost a lot of money though, which is the downside. Should anything happen to it, it will be harder to service than my 2009 model. But again, it looks like a more robust build. It will be interesting to see where Apple takes the Mac in the next few years though. The newly released 2020 model is perhaps the last Intel iMac they will make. It's an impressive machine in terms of performance, but knowing Apple will switch to their own silicon means it doesn't make a lot of sense to buy Intel Macs right now. Anyway, it could be that Apple will be able to make Macs cheaper or much faster or both. It's something to ponder before switching back to Windows or Linux in the future.
I baked my card last week. I have a 2011 27” iMac A1312 model with AMD Radeon 6790m GPU. Which I baked @ 390 for 8 minutes. After putting everything back together, Upon turning it on I get the one chime, but the screen is blank and after about 30 seconds the fans go full blast. What did I do wrong?
It’s difficult for me to believe that one or two minutes difference would cause a bake to fail, but my first bake was 9 minutes and all bakes thereafter were for 10 minutes. Clearly the bake did not work for you, but I cannot explain why. Assuming you cleaned off all of the old thermal paste before you baked the card, and assuming you used new and good thermal paste after your bake, you really have two options at this point. The first option is to try the bake again for 10 minutes and see if that works. If it doesn’t work, then your only other option would be to look for a replacement video card on eBay.
I cleaned all old thermal paste off board before baking. Used Artic silver 5 thermal paste before install on all necessary areas. As far as the P Ram , not sure how to honestly. And the Ram, not sure what you mean by resetting.
@@OwensB I am 99.9% certain that a reset of PRAM, a reset of the SMC, and a boot into Safe Mode will NOT resolve your problem. I say this from practical experience, knowing that when you have a video card problem, none of those things can resolve it. Nevertheless, if you deal with Apple Support folk, those are the first things they ask you to try because one of those things can often help resolve a variety of Mac software and even hardware related problems -- just not problems pertaining to a damaged video card. You can try that if you like, as per Apple's support pages here: support.apple.com/en-us/HT204063 support.apple.com/en-us/HT201295 support.apple.com/en-us/HT201262 If you ONLY used Arctic Silver V paste on your baked video card, it WILL be a problem. The reason is because you cannot use that paste on the memory chips. The original paste Apple used on the memory chips was a THERMAL PAD. But because we cannot precisely measure the gap between the heatsink and memory chips, I personally use K5 Pro, which is a special, thick thermal paste made especially for thermal pad replacement. You must NEVER use K5 Pro on a CPU or GPU though. It's only for times when you have a gap between a heatsink and low-heat chips like those memory chips. As to your use of Arctic Silver V on the GPU, I did that too on my first bake, and it lasted only 4 months. Arctic Silver V is electrically capacitive, which means any spill-over from the GPU onto the surrounding SMD capacitors will alter the amount of capacitance and potentially cause your video card to malfunction. That is why I used a non-electrically conduction, non-capacitive paste after my 2nd bake. I used K4 Pro because it often comes bundled with K5 Pro. You could use another paste like Thermal Grizzly Kryonaut (the best CPU/GPU paste out there), but you still need K5 Pro on the memory chips. All said, you may need to remove, clean, do a 2nd bake, then apply the pastes I recommend before your machine will start working again. However, please also note that this isn't a 100% guarantee. It works for most people (see the comments), but not all. If your video card really is on its last legs, further bakes won't help. But sadly, the only way to know that is to do another bake. If that fails, your only recourse would be to get a replacement video card. I hope this helps!
@@OwensBYou are going to where you would add memory to your computer, open up the bottom of your mac's memory RAM storage is remove any dust that might be there, pull on the plastic tabs to release the memory boards pull out and clean contacts, replace back into computers top slots first ( must have a least one memory board in top slot so the computer will boot. Resetting and testing each memory board to make sure they are still good (a bad one will keep your computer from booting). Taking them out and putting them back in and making sure they are seated in their slot is all you may need to do sometimes to get the Mac booting again.
On my second oven bake. Ok..here is what happened to my mid 2011 27" iMac , I shut my computer down at night (normally I leave it on sleep mode). what I did not realize was my fan speed control software reset to default which is way too slow, my iMac has the GPU heat-sink mounted at the top right hand corner of the case with cooling pipes extending down to the center of the GPU, in theory the fan below the disc drive is tasked with the job of cooling both disc drive and GPU heat-sink...this in my opinion is the design flaw, There is no way that fan mounted near the bottom of the case is going to deliver enough air to the heat sink unless the fan is set at about 2400 RPM. At one point I had readings of over 125.F at the GPU diode, My bake method was 425F temp for 10 mins in the convection oven which fixed the card. I blocked the opening below the disc drive with electrical tape so fan air would travel in a more direct path up behind the disc drive towards the heat sink. My GPU card is currently reading 97.F at the diode and 89.f at the heat-sink with a disc drive fan speed of about 2353 RPM..I just keep watching the fan speeds and temps and so far so good.. i did have the card go out on me prior to all of this with pink bars on a white screen-but I shut down quickly and everything worked again after a few hours..so I had suspicions about over heating.
Russel, thank you for the detailed explanation. If indeed you baked your graphics card at only 225°F (107°C), then I cannot say how long that bake will last. You see, the bake needs to be done at 200°C which is roughly 392°F. Many people who cannot bake with that much precision just use 400°F. That would be about as hot as you would want it to be when baking for 10 minutes. Baking at lower temperatures like 225°F (107°C) may do some good, but I am skeptical if it will last a long time. Honestly, I've never baked at such a low temperature myself, and no one in the comments has reported that either, so I am eager to hear how your bake does over time. Also, what thermal paste did you use after your bake?
@@JDW- actually I was mistaken- I baked at 425.f for 10 mins and used very little thermal paste (Arctic Silver brand) and only on the GPU chip, the heat sink only has contact on that part of the GPU on my machine. I am thinking the memory may not need cooling other than passive air. As I had mentioned the GPU went out on me but I turn it off fast for 2-3 hours and it booted up fine..later I had the card fail again I did the bake method again and found the fan system was running back a default after boot up..anytime I see the temp running high i just set to full blast until I see it at nominal temps. If I do a full shut down I always check the fan settings and keep them around 2500 RPM..also the mac fan control software is a free download and I upgraded to the pro version -but this is the same as the free version so I wasted my money. thanks JDW for your videos..yeah I love my Mac too much to dump it and these machines are too expensive to buy new. My 2011 iMac is still quite powerful with its i7 CPU.
@@tallisrocktube Thank you for your reply. 425°F is 218°C. Hopefully no components fell off at that temperature. That excess heat will definitely take care of the GPU chip problem though. I used Arctic Silver V after my 1st bake, which lasted only 4 months. The problem with that paste is that it is "capacitive." Any paste that spills outside the GPU chip may touch the tiny surrounding surface mount capacitors, and that could cause issues. But since you used "very little" of it on the GPU, there may not have been much overspill once the heatsink was locked down. Since you said the card failed again after that first bake, I would say it was definitely your thermal paste job, especially because it seems you did not repaste the memory chips. Fan speed adjustment is important, but thermal paste is extremely important. That is why I recommend either K4 Pro or Thermal Grizzly Kryonaut for the GPU and K5 Pro (a thermal pad replacement paste) for the memory chips. If your graphics card fails again, I would try that kind of repaste. Even so, it's important to keep in mind that you cannot keep rebaking those cards forever. In my case, I got 4 months of life from my 1st bake (due to my inadequate thermal paste job) but then I got 2 years and 9 months from my 2nd bake, and then my 3rd and 4th bakes lasted only 1 week, so I gave up on the 4850 card and bought a 6970M, which I continue to use to this day. Best wishes!
Hi JWD, i have an 2011 27" IMac, 12,2. 3.1 Ghz Intel Core I5 (8*2) 16 GB 1333 MHz DDR3 AMD Radeon HD 6979M 1024Mv High Sierra. It's have random screen freeze issue whenever what software or work I'm doing. it's just freeze at where i working at and all the mouse and keyboard will not work. I have to hard/physical shut it down May i know i should change the GPU or graphic card in order to solve the problems?
Based on what you told me, you would either need to bake your video card as shown in my videos or completely replace the card. The CPU doesn’t have anything to do with that problem.
I always heard its a very bad idea to use an oven you are going to cook food from later due to the wide range of chemicals that come off these electronics when you bake them.
The temperatures we are talking about in this bake are not hot enough to completely desolder components and therefore you’re not going to have smoke from residual flux nor any significant airborne chemicals. There were no bad smells at all after either of my bakes. My last bake was 2 1/2 years ago, and I and my family are currently in perfect health. If one is worried, one need only wipe down their oven after the bake. If you are still worried, then you could try the heat gun technique although that would require a bit more skill to ensure you do not completely desolder any of the components.
You can do the same fix in 5 minutes with hot air blower by putting the iMac on it's back on the floor (display up) and blowing hot air through the bottom right side vents and turning iMac on so that the fans will distribute the hot air to the GPU. That way the processor of the GPU will fasten again to the circuit board because of gravity. :) I did that baking thing 2018 and my 2011 iMac worked almost two years without any problems but now tried this easier and quicker method and it worked right away. Hope this tip saves someone's time and nerves.
I certainly welcome all new ideas to repair defective video cards. However, your suggestion does merit some level of open-minded scrutiny. First, it would be nice to see a video showing clearly what you have described. Based on your text description, it would seem that the "hot air" (at what precise temperature you did not mention, and that really is key) would hit more than just the video card and the repercussions of that are unknown. Indeed, you are the first person to ever suggest this trick. The long term viability of your technique is also unknown. Prior to doing even my first bake, I spent a lot of hours checking experiences of others, which included watching TH-cam videos and seeing how long these folks were getting from their method to fix the video card. After being satisfied with stories of longevity, I decided to try it myself. And after a few years, I think we've established that the bake really can last long enough to make it worthwhile, and it does not have ill effects on other components inside the iMac. So while I am not saying your method is wrong, some people probably will naturally want more information before trying it themselves. As such, I would encourage you to make a video on the subject and then keep people informed about how your video card does over time. That's pretty much what I've done with all my videos on the subject of the video card bake. Thanks!
Bad idea. You do not want heat components other than problem which is GPU. Heating through vent will risk damage to the LCD. Removing the GPU gives opportunity to renew the old thermal paste which is likely dried out and ineffective. Don't be lazy. Do it the right way.
@@encinobalboa I changed thermal paste 2 years ago so it's not very likely dried out. I don't know the temperature of my hot air blower but I kept it 40 cm away from the bottom vents for 5 minutes. The fix worked only a short while and I'm going to try it again soon as I'm too lazy to get the GPU in the owen this time.
@@livescape9115 Lead free solder (the crap AMD uses in the 6970M) melts at 217C which is why bake is 200C. We want to control heat so solder re-flows in place. You would have to apply much more hot air than 200C to reach the GPU through the vent. In the meantime, you will be melting the plastic in your LCD. We can do this your way or the right way.
@@encinobalboa OK, I see. I'm just too lazy to do the baking second time. In a local Apple repair store replacing the GPU would cost 900 euros that is way more than the price of the 2011 iMac in the aftermarket. Maybe I try to set up my nerves to stand that baking process again.
Hi JDW, last night i see all yours baking videos (with subtitles, because i'm italian and when you talk fast i lose some words). This Sunday i will try one similar thing with an Imac 27" mid2010, because now we have only magenta and pink vertical lines on screen, without the Apple logo. Just the initial bong. No safe mode or recovery allowed. With my son will do a video of the experience. It will be different fom your because we will use a technic phon and not a oven (my wife doesn't want !). I will concentrate the hot air on GPU and, if it works. i will do a secondary operation changing the termal pad with your K5PRO. For the moment i will use only my Artic Silver AS5 on the GPU and heatsink. With this pandemic problem all shops are closed and the online is very slow. We have to stay at home, so we will spent our time with this experiment. Thanks for your videos ;.) My problem is here www.imaccanici.org/forum/ucp.php?i=pm&mode=view&p=30600 Best regards
Grazie per aver guardato! È molto importante applicare circa 200 ° C alla GPU. Applica quel calore per diversi minuti. Un asciugacapelli potrebbe funzionare, ma mettere un foglio di alluminio sulle altre parti del circuito stampato in modo che solo la GPU ottenga la maggior parte del calore. Inoltre, assicurati che ArcticSilverV sia nuovo. Non utilizzare la pasta termica di età superiore a 1 anno. ArcticSilverV è "capacitivo". Pertanto, si prega di applicare solo una piccola quantità al centro del chip GPU. Se si applica troppo ArcticSilverV, la pasta termica in eccesso si spremerà e potrebbe toccare i condensatori circostanti. Ciò potrebbe potenzialmente causare problemi. Dopo aver finito, per favore fatemi sapere se avete avuto successo. A proposito, non parlo italiano. Spero che Google Translate abbia fatto un buon lavoro su questo! ------- Applying approximately 200°C to the GPU is very important. Apply that heat for several minutes. A hairdryer might work, but put aluminum foil over the other parts of the printed circuit board so that only the GPU gets most of the heat. Also, make sure your ArcticSilverV is new. Don't use thermal paste older than 1 year. ArcticSilverV is "capacitive." Therefore, please apply only a small amount in the center of the GPU chip. If you apply too much ArcticSilverV, excess thermal paste will squeeze out and possibly touch the surrounding capacitors. That could potentially cause problems. After you are finished, please let me know if you had success. By the way, I don't speak Italian. I hope Google Translate did a good job on this!
@@JDW- Hi JDW, today I have tried two times to reflow the graphic cpu... but I have lost my battle. Same vertical lines and no boot. So I need to find another graphic card like mine (Radeon HD 5750 1GB) or try an upgrade to a model from mid2011, like Radeon HD 6970M 1GB. Is it 2GB your upgrade ? Last chance, sell any part off the iMac. Thank you and Best Regards.
@@cristianomarchi9525 Please see my newest video about the 6970M I just installed, and be sure to then read my Pinned Comment in the comments section for the caveat I discovered last night. th-cam.com/video/9dPsH1zIQMs/w-d-xo.html
As mentioned in my 3rd bake video, the 2nd bake lasted 2 years and 9 months: th-cam.com/video/teV_atLUlpM/w-d-xo.html But my 3rd & 4th bakes only lasted 1 week, telling me the card could not be baked anymore, so I am now using a 6970M, which has been working almost 2 years now. For more info on that and all my bakes, please see my Playlist of videos here: th-cam.com/play/PLNZ4qjMn-GHoez6_PtpyJfcU_ialTS8bB.html
4/18/2020 Just watched your Bake 2 video have the same late 2009 27" iMac with all the same issues of not booting except in safe mode and the horizontal lines, bad design for the GPU card. Glad to see this response video instead of having to read through all the comments. Need to get the thermo grease 4/5 from Grease before I try the bake and I agree that in 2020 that the 2009 27" iMac is quite useable with OS High Sierra installed on it. Question I still have is how hard was it to reconnect the temp cable back on the motherboard after the repair? Hate to loose the use of a perfectly good Mac as my daily driver.
Reconnecting the tiny 2-pin connector to the back of the motherboard (a connector that leads to the temperature sensor on the video card) is difficult if you don't partially remove the motherboard to pull it forward enough to see the mating connector on the motherboard. However, I have enough experience at it now that I can, with a fair amount of trouble mind you, get it connected without removing any motherboard screws. Practice really does make perfect! But for you, I would suggest leaving most of your motherboard connectors intact, then remove most of the motherboard screws so you can see well enough to get that little guy into its mating connector. I would also suggest using fingers instead of a tool to ensure you don't accidentally rip one of the wires out of the connector or otherwise do accidental damage.
You should upgrade your card with Nvidia Quatro K1100m or K2100m. You'll have metal support, brightness control, you can run Catalina with dosdude1 patches and there will be no overheating.
Thank you for your suggestion. I have a reasonably working 6970M right now so I lack the incentive at this time to try another video card. Flashing the card you mention either requires a Mac running Windows in boot camp or a true Windows PC, neither of which I have setup right now. If and when my current 6970M fails, I will of course investigate the cards you mention and make a video on that experience at that time.
I appreciate the tip, but we are a Mac-only household. I’ve used Macs exclusively since 1984, in fact. And while I have some limited experience with Windows, I have zero experience with Linux. Even so, your tip will be of help to others who may have experience with Linux. Thank you.
Unless you intend to also replace the button cell battery too, I would recommend you follow my 2nd Bake video. Be sure to buy the required two types of thermal paste I recommend. And to give you further peace of mind, put an oven safe thermometer like a Turkey Thermometer inside your oven during the warm-up period to verify that your oven's temperature dial is accurate. If it's too much more than 200°C or 394°F, components can become desoldered. Most people don't have issues, but a handful of folks with problematic ovens have reported desoldered components, which is why I recommend verifying the temperature to be 100% sure nothing will go wrong during the bake. Be sure to make the aluminum foil standoffs as I recommend, then bake for 10 minutes. After that, leave the oven door open and let the card cool to room temperature, repaste, reinstall and test. Also be absolutely sure you clean off all the old thermal paste before your bake, not only on the graphics card but also on the heatsink too. If you still have doubts, I would encourage you to read through some of the comments under my 2nd or 1st bake videos. I read and reply to every comment. Most people who try the bake have success. Good luck, and please let me know how it goes!
I don't get them people who bash people for baking their stuff, I mean its broke, what do you have to loose? Bake that sucker, if it don't work, it don't work.
Hi there, it's me again after 8 months. I finally replaced the GPU and the iMac works perfectly fine with an external monitor, but the internal stays black. I can't see anything using a flashlight, three diagnostic leds are on, 4th is off. The internal display is not shown in "about this imac", only the external one. Also, the v-sync connector plastic shield is broken, but all 4 pins are fine and the cable is seated tightly. I read that display should work even without the v-sync cable connected, so I don't think this is the problem. Options are: - broken LCD - broken ribbon LVDS cable (i broke the original one and replaced it, but the new one could be damaged too, idk) - broken LVDS connector (but it looks fine to me) - something else on the logic board Any other ideas? :
I'm sorry to hear that. When lit, LED#4 shows that the iMac's motherboard and LCD panel are communicating. LED#4 should be ON when the computer is turned on and video signal is being generated. It's only when LED#4 is ON and there is no image on the display, that the LCD panel or LED backlight board or the cables between might be installed incorrectly or need replacement. Because you are never seeing LED#4 come on, Apple has the following advice... • Verify cable connections between LCD panel and logic board • Inspect LCD display cables for cable damage • Verify external video functionality, and according to result check the following items: -If external display works then verify/replace the LED backlight board -If external display works then verify/replace the LCD panel -If external display does not work verify/replace the logic board
I would say just buy a new GPU, but even they're prone to cracking, it's just bad hardware design on Apple's part and inadequate cooling that causes the actual dye of the graphics chip to crack with heat stress.
I later did buy a different graphics card, and I made a video about that at the following link, and I’m pleased to report it’s still working to this day in May 2024. th-cam.com/video/9dPsH1zIQMs/w-d-xo.html
Hi, My Apple Imac 27 Inch Crashing Randomly, Going in boot loop,Getting Vertical Lines, Some times Green Screen, Some times blue. I try all solution. Safe mode, Recovery, Reinstall OS,Re install Old OS, Install Windows... Went through million solutions and forms to make it work Only reflow GPU card solution work.Open Imac take out graphic card,Clean & wash properly all thermal paste, Heat Oven 200 C. Keep GPU card on small Aluminium balls, Keep in oven for 10 minute. Let it cool for 30 minute, Get new thermal paste not conducting electric type apply small amount on GPU & all other black component jut like doing painting . Do not apply thick layer. Just enough to cover. Like paint on wall. Tight all screws properly firm & reinstall card. It works 1000%. I have wasted many week & spend lot of money. All the best.......Thanks
I propose you attack the ROOT CAUSE of the Over-Heating GPU. Although my 1st Bake lasted 3 years, my 2nd Bake failed and I started to think more about why is the GPU failing in the first place. I believe the Thermal Design on the 2011 iMAC EMC2429 is a total Failure (ODD FAN air-flow goes under DvD/CD drive to finally get to the FINS( 6" away) to the 3-pipe L-shaped GPU Heatsink. History: 1st Bake Mar 2017 Pass, 2nd Bake May 2020 Fail. 3rd Buy used GPU card on eBay, advertised as Tested Good. Proposal: 1). Propose removing DvD/CD drive and install a new USB Blower Fan (AC Infinity MPN: AI-MPB140A) 35 cfm in the same location (which is very close to the actual GPU) 2). Remove 3-pipe L-shape heatsink and install a standard Heatsink ( MXM-type B) (max pwr 200W) Heatsink w/bracket for AMD 7650A 3) Install a thermal sensor cable to the new Heatsink. 4) Remove the existing ODD FAN as it has NO USE in the new approach (new USB Blower Fan blocks air-flow from this existing ODD FAN.) I need HELP in finding an appropriate HEATSINK and THERMAL SENSOR CABLE......still looking Found this Heatsink w/bracket for AMD 7650A on eBay.
Thank you for sharing such detailed thoughts. My newest videos on this topic talk about the AMD 6970M that I purchased and am currently using. You may wish to watch those two videos for all the details of what I have done and what is going on now. But as to your proposal about removing the optical drive, using a different heatsink and fan, that would be an interesting mod, although the average iMac owner really wouldn't have the ability to do all that, I don't think. Many people have been reluctant to do the bake, but they manage it because my videos show them everything step by step, and it's not really a major mod of their hardware. Even so, if you ultimately do the mod you propose, I strongly suggest putting your iPhone or another HD camera on a tripod and filing every aspect of your experience. That info would be useful for others. Lastly, it seems you were going to post a link. That's perfectly fine. I don't block links. I do think you forgot to post the link though. I honestly do not know what thermal sensor would be compatible. That really is key to getting it to work with the iMac. I've never measured the signals going between the motherboard and the heatsink thermal sensors on the 4850 or 6970M. That information is crucial though to knowing what sensors would work.
@@JDW- it looks to me like the existing Thermal Sensor Cable can be removed from the 3-pipe L-shaped Heatsink, if you can remove the Copper Shim on the opposite side? So I plan to use this existing Thermal Sensor Cable on the new Heatsink.
@@JDW- 1) to move DVD/CD drive outside the case. Drill larger hole in bottom of case to accommodate the extension cable for the DVD+/-RW Drive. here is the cable description> 50cm Length Slimline SATA 13pin Male to Slimline SATA 13pin 6+7 Female Extension Cable for SATA Slim DVD+/-RW Drive. www.amazon.com/Length-Slimline-13pin-Female-Extension/dp/B078J2VQMP
Thank you for the instructions! I fix one iMac (27-inch, Mid 2011) with this technique. Card to the oven with 200°C 10min and K4 K5 thermal paste etc. Everything works fine now! I have a bit newer model, so removing the graphics card was harder, and I had to touch the motherboard. Here is some idea how to do that part: th-cam.com/video/hRtB6VBDiSU/w-d-xo.html
Thank you for your kind comment and for the link. As you can see in that video though, there are issues you must deal with when trying to use non-stock video cards. That is for serious enthusiasts rather than most people, which is why I have not yet done a video on those cards. For most people, the bake tends to work at a low cost. And I think cost matters because most of us are trying to resurrect computers that are 10 years old. And while some PC cards are rather cheap, time is money, and you really do need to spend a fair amount of time flashing and doing things to get non-stock card to work properly. Even then, there could be certain OS incompatibility issues to deal with. That is why I am content to use the 6970M in my late 2009 27" iMac for now. A higher fan speed combined with room A/C switched on keep the card running cool enough to where it is perfectly fine now as a daily driver.
![Late 2009 iMac 27" Video Card Repair [4850 Bake]](http://i.ytimg.com/vi/v1DXBLkiqFM/mqdefault.jpg)
![Late 2009 iMac 27" Video Card Repair [4850 Bake]](/img/tr.png)
0:22 2011 not 2012, that was the year they went to the "Tapered Edge" design with a soldered GPU.
You are correct and I have updated my text description accordingly. iMacs that did NOT have the tapered edge were sold in 2012 up through October 2012 and so those non-tapered iMacs with removable video cards ARE covered by the bake, but technically they would be "2011" models not 2012 models. I should have made that clearer in my video. Thank you for clarifying that very important point. I have pinned your comment so it would perpetually be at the top of the comments section for all to see.
I baked the card in my iMac 2010 27 inch yesterday (200˚C, 10 min). This is my second experience. Before baking, the the screen was full of lines. Now, at least at this point, it works perfectly. I did my first card 3 years ago after watching your videos. And this time, I also checked your videos again to make sure every step is OK. Thank you so much!
It is unfortunate that the bake doesn’t last forever. But I’m certainly pleased to hear that your second bake was a success! I hope you get at least another a few years of use out of it! Best wishes.
For me it ‘s been 1 year now ... using your video and doing the bake for my late 2009 iMac 27 ... and it’s still working 🤗. Thanks again for your great videos 👍🏻.
That's wonderful to hear, Benoit! Thanks for letting me know.
JDW, Thanks for your videos (I watched them all). This works! I just baked my 2011 27" iMac's AMD 6970m GPU and it works again. I simply followed examples shown in several of the youtube videos including yours. I have never done anything like this before. This was the first time I opened up my iMac. While it seems intimidating at first, I did it. The hardest part was reconnecting the power cables behind the Logic Board and from the LCD panel to Logic Board. I put a sequential numbered piece of electrical tape on all of the wires and it went together smoothly. Baked at 400F for 10 minutes. Took about 3 hours to fix. My thanks go to all of the TH-camrs who filmed the process and also to those users who posted their encouraging success stories too.
This video deserves more exposure. I've been searching for information about this for quite a while, and it's only today that this video shows up, and it condenses a lot of the info needed to try to fix the video issues, wish I found this sooner.
Thank you. You can find all 8 of my videos on this topic here: th-cam.com/play/PLNZ4qjMn-GHoez6_PtpyJfcU_ialTS8bB.html
Hi JDW, many thanks from the Netherlands for your video. My 2009 iMac i7 broke down and after reviewing your video's, I was able to repair my iMac. At almost no cost! I was really thrilled when I started up for the first time after the baking procedure and to see that my iMac was alive again! Again, many thanks!
Thank you for sharing your success story. Best wishes to you and your newly resurrected iMac!
I just baked my graphics card for the 3rd time 2 days for 15 min. At 405 degrees ( I suspect our oven isn’t as hot as as it should be). K5 pro (the goopy stuff) and Kryonaut on the chip. It never ceases to amaze me that this works but I figure I have nothing to loose! The first time lasted a few months, 8 min, 392 degrees. The second time was 15 min. 400 degrees lasting 6 months. I think the Greece was the problem MK ?something. I think that it wasn’t goopy enough to fill the gap on the other small chips. I think it was your video that prompted me to buy the K5 pro otherwise I was looking at buying pads. Thank you!
Hi, Sandy. Wow, 3 bakes! Well, I am sorry to hear that because I know how much time each of those took you! 405°F is 207°C which is roughly the right temperature, assuming your oven really is that temperature. You can check it with a turkey thermometer to be sure. So you used MK-4 on both the GPU and memory chips after your first 2 bakes? If so, that would explain it. MK-4 is great for the GPU but not for the memory chips which require thermal pads. They require the pads (or a thermal pad replacement like K5 Pro) because the gap between the top of those memory chips and the heatsink is quite big. I believe that led to my 1st bake lasting only 4 months. So your case lends more support to that theory. Anyway, I'm hoping you'll get 2.5 years+ like me on this latest bake! Best wishes in 2020!
First, thankyou for an excellent and detailed video. I also had the same issue (100's of artefacts) with my iMAC mid 2011 27" i7. I baked my card and applied the K4 and K5 paste as per your second bake video. It's only been two weeks but in this time no issues. Indeed, having gained the confidence to take my iMAC apart I have installed a 120GB SSD as my system disk (including the recovery partition) and keeping the 1TB HD as my data disk.
That’s great to hear. Thank you for letting me know your story of success, John. Best wishes!
Thanks for these videos JDW. Tried this on my 2009 iMac back in Sept 2018 and has worked perfectly for the last 18 months till last Sunday. Redid the bake on Monday and so far working perfectly again, hopefully at least for another 18mths.
For anyone trying this be super careful of the first ribbon cable in the top left with the blue backing, the one JDW had to replace in the video. Its very fragile and even if you are careful not to tug on it as you open the screen it clearly is not designed to be handled frequently either and will start to de laminate on the end. Cheap to replace but good to avoid the hassle if you only have the one computer.
Thank you for sharing your experience, David. What thermal paste did you use after your first bake?
@@JDW- Hi, as I didn't want to go to too much trouble over an old machine I just purchased what was available locally which was the Duratech Nano Diamond thermal compound. Interestingly the heat sink gap was very narrow compared to yours (maybe 1/2 a millimetre) so didn't need to use much paste at all.
There is no better Video of disassembly in all you tube of the Imac 27 it is the BEST TUTORIAL, I also believe that the paste that you recommended from Greece it is the best, I think that is the key when you bake this card, I have 2 imac 27 2011 Imac 27 i7 3.4GHz iMac with an AMD Radeon HD 6970M 2048 MB has been bake almost 2 years ago and still working My wife Imac same specs just last 1 year and a half bake again and it is working, this is how I do it: I preheated the oven and baked the graphics card for about 9 minutes @ ~380-390°F (about 200°C). I then let the card cool down for about 30 minutes. Mr. Rossman is the best on the field and it is right but nobody it is perfect. Happy New year. Cesar.
I am humbled by your very kind words, thank you. Thank you also for sharing your multiple success stories, as well as for providing details on how you do the bake. Happy new year!
Just did my graphic card back an hour ago and it was a success. My 2009 imac symptoms was, when power up, it was stucked in boot chimes over and over again. LED 1 LED 2 and LED all lighted up except LED 4. Decided to do the "bake" after seeing success online. after baking for 7 mins at 200 degree C. installed every back, the imac boot up like a charm!
Thanks for watching and for sharing your success story! Best wishes!
Hello JDW, hope you’re well. I wanted to thank you for your videos on reviving these iMacs. Mine is a late 2009 i5, 2.66. I’m just getting the tools to carry out this procedure. I’ve not done this type of thing before but am looking forward to bringing my iMac back to life. I think the main things is keeping everything labelled (as you show in your 1st video). It seems slightly daunting but I think I will achieve success with your guidance. I’ll let you know how I get on. Thanks again, Jerome
I’m quite excited about doing this actually! I love a challenge!
If you follow my video and if you have read through the text description under my video, you’ll do fine. Just keep it slow and stay calm. When you take out the display, just make sure it doesn’t fall forward, so you don’t break any of those ribbon cables. I read and reply to every single comment under all my videos, and I can tell you that the vast majority of people who try the big or successful. As long as you use a good thermal paste, your bake should last a long time. Best of luck to you, and be sure to let me know how it went.
Thanks for your reply. That’s great advice and I will follow your directions carefully. I am just going through the videos again to reinforce what I’ve learned so far. Thanks again and I’ll. let you know when I’ve got the iMac back in action.
You should have more subscribers. You're channel is excellent. Keep it up!
Thank you for your very kind words, JJ. More subscribers would be a tremendous blessing indeed in light of my day-job/salary situation. Things were bad enough before Corona hit, but now it's just awful. I enjoy making quality videos that help people, and I wish I could support my family doing such work. Anyway, I am currently shooting and editing a new video about the Macintosh 128k~Plus Analog Board. Stay tuned!
I did a bake about 2 years ago on a mid-2011 iMac graphics card.... and it bought the unit back to life. I was sceptical before trying it but felt I had little to lose by giving it a try.... I was surprised but also delighted that it worked....
Thank you for sharing your success story, John. Does this mean your baked card is still working today, now 2 years later?
It was..... but the iMac went belly-up a couple of days ago. At first, I thought it was a drive problem as the symptoms didn’t match the first time the GPU played up..... but, eventually, I narrowed it down so the GPU seemed like the most likely issue.... and that’s why I started to re-watch some of the TH-cam stuff to refresh my memory of what was involved. Anyway, took it apart today, baked the card and, yay!, it’s solved it again. The machine is now working again..... :-)
@@JohnWaldenDDM Well, it is a positive sign if your first bake lasted 2 years. My first bake lasted only 4 months, although that was likely due to my bad thermal paste job. My 2nd bake lasted 2 years and 9 months. My 3rd and 4th bakes lasted only a week each. So if your 2nd bake lasts longer than a week, then I would say it probably will last for a considerable amount of time. Please keep me informed on how it does over time!
Used your video to repair my 24-inch '08 iMac just two days ago. Different computers, same idea though. Baked the video card and it has been working since. Much appreciated!!
Thank you for letting us know the bake works even on the 2008 24" iMac, Ryan!
@@JDW- an unfortunate update: the system is starting to have issues again when powering on from sleeping. Hoping that I could maybe get it working once and for all with another bake like you did. Can't really complain since I got the machine for free and gained a ton of experience out of it. Guess I'll get something a bit newer!
@@cassadagaa What kind of thermal paste did you use? Did you fully clean off the stock thermal paste before your bake? What was the temperature and time of your bake? My 1st bake lasted only 4 months and I strongly suspect it was due to the fact (1) I didn't clean off the stock thermal pads on the memory chips and instead added new paste atop those, and (2) I used Arctic Silver V on the GPU which had some overspill. Arctic Silver V is capacitive, so any overspill onto surrounding components could cause problems. After my 2nd bake, I used K4 Pro on the GPU (which is not electrically conductive or capacitive) and I used K5 Pro on the memory chips, since it is designed to work well in that application where there is a large gap between the top of the memory chips and the bottom of the heatsink. Maybe you could say it was a second bake that also helped too, I don't know. All I know is that I have gotten 2.5 years of use out of that 2nd bake and thermal paste combo, and the machine is still going strong. I hope this info helps you decide what to do.
@@JDW- I used the same paste you did (Arctic Silver V) but I did something pretty stupid: I decided to just leave some of the stock paste on the memory chips and not even bother putting any new paste on. I decided to give it another go in oven.. Unfortunately, I think I killed it. Only a white screen on boot up and nothing more. Decided to cave in and get an ATI 2600 HD Radeon for it (since these 8800 Nvidia cards are notorious for failure). Some good lessons learned nonethless.. I must of taken apart my iMac 10 times during this whole procedure! Thank you again for the very helpful video!
@@cassadagaa Thank you for the follow-up info!
My 2011 27" had its 6970 fail in December 2021. I got it fixed in time to start 2022 and start a new chapter in its life. At this moment, it's been doing fine for 7 months.
At the time of failure, it fell hard and fast, working great all along then going kind of frizzy and straight into the shutdowns and boot loops. Down for the count.
I cleaned the interior of the machine and because it's a 2011, it required the removal of the entire logic board. I replaced the battery (a regular lithium 3v will do because I use SSDs that don't generate the temps that rotary HDDs do). Removed and cleaned the CPU while in there, and repasted before putting it back.
Reading and viewing all kinds of opinions about oven temps and bake times, I put the card in about midway through the preheat, left it in for 10 minutes at 390F, and then opened the door to bleed heat for a bit after that timed period, then let it cool inside the closed oven, and opened up again to finally let it get to room temperature. There was enough difference of opinion that trying not to shock things into 'too hot' and cooling too fast seemed a sensible way to go.
I didn't have 90% alcohol but with 70% I did a few passes of shining things up and letting the parts dry well. Dry climate here in the winter, so maybe that affected things favorably.
Custom cut thermal pads to fit the VRAM chips. Some required stacked pads to fill the gap consistently, using different thickness sheets. The GPU die itself got Arctic Fox paste. Took my time rehearsing the fit before committing to the paste and pads.
Because this was a 'wait and see' procedure, on reassembly I left out the ODD entirely (I actually had an SSD adapter there), and a moulded piece of plastic that divides the ODD area from the HDD area. It seemed superfluous. I also just electrical taped the SSD into place. All told, there is much more contiguous space inside for airflow. The lack of ODD means the right side fan can target the GPU heat sink directly. There is a bit of physical noise. I guess the plastic piece was a bit of a dampener. As of now, I won't mess with a working unit but I guess I'd put it back in.
Then goes the fun part hoping to get all the parts back together and get the three LED signal at startup (indicating the GPU is being engaged).
Reset the SMC and NVRAM on starting up. Good to go. Yay!
The only thing I have seen not work right does not particularly affect my actual usage. Geekbench testing must have pushed things too far. In a series of 4 tests over a few days, there was a predictable delay in the test speed, then a spontaneous blackout and a return to the login screen (but with lo fi display res), and then on logging it it would black out again for a while, then return to the full res login screen where I could log in and go on with things. It did this predictably in High Sierra.
I've been using Opencore Legacy Patcher for a while and this spring I got Big Sur going on this machine, still with the baked card. Doing the Geekbench test takes way too long BUT it does not do any of the other oddness with blackouts and login screens. But again, GB is an unusual case and is not my daily usage. Otherwise, the machine went from being a retired studio machine last year to becoming a general daily driver for me to do all the web stuff, TH-cam, and all that kind of general use stuff. With OCLP and Big Sur it doesn't feel old at all.
Seven months so far with the baked card.
I have a different iMac with a K2100m. It has been going for nearly two years now. Has four different OSes on it including Monterey 12.4--presently the last of the line if the Kepler cards can't be made to work with OCLP's help. But between replacement GPU and OCLP, that is a huge extension of the old iMac's life.
Nice video. I can confirm the "oven bake" works very well: baked a AMD Radeon HD6970 card in my pre-heated oven at 205C for 10 minutes and turn down the temp and open the oven to let it cool down, from a mid-2011 iMac 27" 4 months ago and it is still working well. I also use Mac Fan Control with sensors controlling individual fans. The GPU die temp is at around 62C and GPU heatsink temp at 52C (Arctic Silver 5) for normal use (not playing any game).
Thank you for making time to share your success story, A C! Best wishes!
Just did my first bake on a 2009 iMac. Seems to be working Ok. Thank you for your videos. It was a great help! I didn't take the mother board off, managed to get it off but putting it back was a little tricky. I used the K5 paste for the chips like you recommended and MX-4 thermal compound on the GPU. It's a great machine still powerful enough to do my high-end retouching.
Thank you for sharing your success story, Haf! Best wishes!
Thank you for this video! It worked for us! It’s been going strong for six weeks now.
That's great to hear! Thank you for making time to let me know your success!
Hello 2020!!! Great Video again! See oyu in the next! My imac still working!
Thank you for your video it helped me complete my first video card bake yesterday on my ageing 2011 27” iMac. Local repair shops told me to junk the iMac for this was my second video card. My first one was replaced by an Apple authorised repair shop under warranty, after the apple store would not fix it for I had added a second SSD, voiding the warranty. I think that if it fails and can not be repaired, I may just gut the iMac and turn it into a monitor.
Thank you for making time to share your success story, Caleb. The bake doesn't last forever, but you should, like me, be able to get at least 2 good bakes out of it before the video card needs to be replaced. How long each bake lasts varies wildly. My first bake lasted only 4 months, most likely due to my inferior thermal paste job (as shown in my 1st bake video). My 2nd Bake lasted 2 years and 9 months. Then my 3rd and 4th bakes failed. I think the 2 years and 9 months was worth the effort of the bake. And although I paid a rather high price for a replacement video card and heatsink (6970M), it is much cheaper than a new iMac, especially when you consider that here in Japan you have to pay to dispose of items. Even Apple Japan doesn't make it's return policy clear. In most cases, you must pay a whopping $50 fee to get rid of old TVs, computers, appliances, etc.
You explain everything very well and i'm getting all my ducks in a row to try the bake. Just a quick query: When I put my iMac mid-2011 27" into target disk mode (cause of white screen and disk recovery only gets as far as spinning globe with triangle and exclamation point) and check out Disk Utility on a second thunderbolted mac, my HD2 shows up OK in the sidebar (which is where I keep all my data) but my main HD is greyed out and says disk4s2 and won't mount. Would this have anything to do with the GPU and do you feel my iMac and all its disks could come back to proper life after a bake? Thanks again!
You should be able to access data on your drive normally after the bake. Sometimes there are booting issues after that bake that have to do with data corruption on the hard drive, but in that case, after the bake, you would just need to attach an external drive or bootable thumb drive or boot from Recovery and run Disk Utility to fix those problems. The bake should restore your iMac to working condition again so you can diagnose your drive in the normal manner and even use Target Disk Mode normally too. Please let me know how it goes after your bake.
@@JDW- Absolutely, I will update you. It sounds very promising...
I did everything shown and there's black screen, bootup chime and extremely loudly running fan after about 15 seconds. Any ideas?
I read and reply to all comments, and in every single case to date, the root cause for the post-bake black screen is either a cable forgotten to be reconnected or a snapped cable. This unfortunately means you will need to reopen your iMac, but it also means the likelihood of your being able to fix the problem by rechecking all cables is very high. The wide ribbon cable in the middle is especially hard to snap into place correctly during reassembly, so pay close attention to that.
@@JDW- Okay, I probably broke that ribbon cable, it doesn't fit well and unplugs everytime try to attach other cars. After like 2 hours I somehow managed to attach it and now the loud fans stooped - just black screen.
Can i replace the cable myself?
@@why4213 I'm sorry to hear that. I accidentally broken the narrow ribbon cable in the upper left during disassembly for my 2nd bake: th-cam.com/video/6BJGLFCigdA/w-d-xo.html
I decided to buy both ribbon cables and replace them (Amazon affiliate links below). If your narrow ribbon cable is fine, then you would only need to replace the wide one. Just made sure it is the cable and not the mating connector on the motherboard that is broken.
• BIG cable: amzn.to/32Ygv7s
• SMALL cable: amzn.to/33ZEvX4
@@JDW- I just tried to connect an external display and well, no signal at all. Does it mean I fucked up something else?
@why421 If there is any kind of major issue with the video card, it is possible the screen will be completely dark, external displays will not work, and you would also not be able to use Target Display Mode.The ribbon cables should impact only the internal LCD though. The bake works for almost everyone who does it properly, on the first time it's tried, although that doesn't mean an automatic guarantee it will resurrect all video cards. So cards are just too far gone to be baked back to life. Let's do some troubleshooting...
1. Are you 100% certain your iMac's video card has never been baked before? (If you're the original owner, you can know that.) If it has been baked before, it's possible additional bakes will not work.
2. Did you clean off all the old thermal paste on the card prior to baking it? In theory, that shouldn't affect the bakes work on fixing the GPU chip, but it's important to clean off all the paste before the bake.
3. Did you use a turkey thermometer or similar oven-safe thermometer to confirm the temperature of your oven is accurate and stable? This is actually an important step, since some people have reported very low temperatures, while others have reported temperatures so high components became desoldered.
4. Did you bake at the designated 200°F or 392°F (400°F is acceptable) for between 7-11 minutes?
5. Did you apply 2 different types of new or almost new thermal paste to the GPU and memory chips after your bake? Note that regular GPU/CPU paste won't work on the memory chips because there's a gap between them and the heatsink. That's why you must use either thermal pads or K5 Pro. I recommend K5 Pro because you then don't need to worry about knowing thermal pad thickness, which can be tricky.
6. Did you follow my 1st Bake video where I removed the entire motherboard, or did you follow my 2nd Bake video where I remove only the video card? I ask because if you removed the motherboard, there are many connectors that you would have disconnected, so reconfirming all those connections is very important. It could be that some connectors look connected at first glance but in fact are only making an intermittent connection.
I baked my radeon 4850 for my iMac, I really hope it'll stay fixed
Thank you for your comment. The bake doesn't last forever, but I do hope you get at least the same 2.5 years out of your 4850 like I did. Best wishes!
I've done it and it worked for 4 years, I'm going to do it again tonight for another 4 years. I own 5 Imacs of various years and they bulletproof except for fusion drives, standard hard drives and this video card problem.
4 years! My friend, I believe you are the record holder. I read and reply to every comment, and thus far, you are the first person to report back with a 4-year bake life span. I love hearing such stories though because it's yet another nail in the coffin for the naysayers who falsely claim the bake either doesn't work or won't last. With that said, in my own experience, there is a limit to how many times you can bake your 4850 card, assuming that is the one you baked. Hopefully your next bake works and lasts another 4 years!
i got another 6 months for mine when I did this, then 2months the second bake, then the third bake, I think it had enough and checked out
It varies quite a lot. One person recently told me he got 5 years from his first bake. I got only 4 months from my 1st bake but then 2 years and 9 months from my second bake. But once the bake stops working, you only get a week or less, and then it's time to replace the card.
A big Thank you for your baking videos. I just baked my late 2009 i7 iMac GPU and it works! Will be interesting to see for how long.
Thank you for making time to let me know your success story, Dan. Feel free to write back in a few months with an update. Hopefully your machine will get the same longevity as my 2nd bake. Still going strong after 2 years and 7 months!
thanks for your videos. I've baked my card following your sugestions ☺
Thank you for your sharing. It's working. I just fixed my 21.5" IMAC 2010. I contacted 2 local shops for repairing. They both said I needed to replace the display card. Luckily, I found your page and it is working now. I have a question. Can we skip the bake and replace the cooling paste?
Unfortunately, you cannot skip the bake. The reason why is because the root problem is not the thermal paste but instead a problem inside the GPU chip. Heating the chip fixes the problems inside it. Of course, after your bake is finished, you need to apply the correct thermal paste before putting the card back in your machine, otherwise all the work you did on that bake will not last very long. I strongly recommend K4 & K5 Pro.
it worked!!!!! my imac 27in A1312 emc no. 2429. awesome thanks for the videos
That's wonderful to hear, Lenin! Thank you for making time to let me know your success. Best wishes!
@@JDW- sadly the LED backlight died a few minutes after it came back to life
@@leninmx Meaning, your display is dark and you do not know if it really is the backlight or if it is the video card again, right? If only the backlight is dead, the iMac should still boot, and you should be able to perform some keyboard action that will make an audible sound, like pressing several times on the F12 volume-up key. If you hear no sound or otherwise have no indication of a successful boot, then it is surely the video card. Did you get a black screen prior to your bake?
@@JDW- it's the back light. I can still see the mouse moving around.
@@leninmx If you never had issues with the backlight prior to disassembling your iMac, then it is highly likely you did not secure one of the connectors well when you reassembled it. You may need to check the dual ribbon cable connector shown at 7:58 in my 1st bake video here: th-cam.com/video/v1DXBLkiqFM/w-d-xo.html
I have a 2008 - 24" - 3.06ghz - with the defective Nvidia (my understanding was that this was the main problem as the Nvdia's were inferior) - My first bake worked great and lasted about a year but with very light use. I used K4 and K5 paste. I'm about to open her up and repeat. I'll be curious to see the condition of the paste and based on what you say - perhaps I should use more to 'fill the gaps' - If successful I will also add the Fan app you recommend. I remember when I originally had the problem, I could get a few more hours before the screen went, just by blowing a fan across the back of the machine. I'll let you know what I find and how it goes... thx
Charles, I’m very sorry to hear your bake only lasted one year. My first bake only lasted 4 months, but I attribute that failure to my use of old thermal paste and the fact I did not clean off all the old paste from the memory chips. Even so, your case is the first I’ve heard of a bake lasting only one year while also using K4 and K5 Pro thermal paste. It seems you did not use a fan control app during that one year after your bake, so I’m curious if my use of that app has contributed to the long duration of my second bake (which is still going strong). But I also wonder if it could be due to my having baked the card twice. I’m not sure. In any case, I have my fan control app set to activate all the iMac fans at a constant 2000rpm. I hope this information helps.
I'll let you know how it goes - one of your 'fan' links is dead - can you send me the best link for Mac 0S 10 - I think I'm maxed out at El Capitan
@@TH-vb6iw Thank you for letting me know about the dead Macs Fan Control link. I just fixed it. The following version is what you need: crystalidea.com/downloads/legacy/macsfancontrol.zip
@@JDW- OK, I'm 2 for 2. Got her up 'n running again - (used more paste) Downloaded Macs Fan onto my 2012 Mini to then move over to the iMac. I see it is set on 'auto'. Once on the iMac, what next ?(settings?) Can you help me with the settings - and if I leave it on the Mini (on auto) will that change anything on the Mini (which doesn't have heat problems). thx C
@@TH-vb6iw To the right of "Auto" is "Custom..." Click "Custom..." Set a Constant RPM value that is higher than the typical. On my 2009 iMac, I chose 2000rpm, which is a fair amount higher than normal, but not max. Max would be too loud. Make it as high as your ears can endure, to ensure better cooling.
Still going strong..just keep those fans running high..now I wish Mac had a O/S update past High Sierra 10.13.6 for 2011 iMac
Although there are ways to get more recent versions of macOS to run on that model, and even though you technically could get even Apple’s Metal to work by way of a flashed Nvidia graphics card, you still would not be able to update the CPU, which would hinder performance. In other words, High Sierra gives you the best performance overall on that older Mac, and that is why I have remained content to use it to this day. High Sierra is a rock solid OS for Intel Macs. To get the most out of Big Sur or Monterey, you really would need an M1 Mac.
hi, me again - I just came into an early 2009 20" iMac with a Radeon 2600 Pro - working - but vertical lines on the screen are distracting - do you know if this one is heatable ?
I cannot speak from personal experience because I don’t own one of those, but I have received comments from people who own 2008 iMacs, and they reported to me that they used the bake with success. I looked up a photo of the Radeon 2600 Pro and I don’t see any electrolytic capacitors on it, which means the bake would be safe.The bake just might work for you.
@@JDW- I've never opened the 20" but I assume it's not too much different from my 24" (except) Radeon instead of nvidia). I'll let you know how it goes - if it works I have someone waiting for me to do another one...
I tried it on a iMac mid-2007 20 inch. I baked at 275F for 10 minutes. Although it didn't work I have a question... you used K5 and K4 thermal paste. Why not just use K5 since it has a higher thermal conductivity? Thanks for the videos.
You are the first person to report having baked the video card from a 2007 model. Until now, the oldest machine reported to me was a 2008. Therefore, I cannot say if the bake works on video cards from 2007 machines. Your experience indicates it is not possible.
K4 Pro has higher thermal conductivity than K5 Pro because K4 Pro is made for use on a GPU or CPU whereas K5 Pro is a thermal pad replacement. That is why you would never use K5 Pro on a CPU or GPU. K5 Pro is made to fill a gap between chips and a heatsink.
@@JDW- thanks. I bought a used video card on eBay and the machine is working now. But I just used what ever thermal paste was left when I put it back together. The GPU had a grey paste and the memory chips had a white paste. I will order some paste from Amazon but was wondering if I could just buy one kind of paste instead of two. Thanks again.
@@brucemerrill7821 I left the stock Apple thermal pads (on the memory chips) intact after my 1st bake. That was a mistake on my part because that bake lasted only 4 months. After my 2nd bake, I did a 100% thorough job of cleaning off ALL the old thermal paste. I then used K4 Pro on the GPU and K5 Pro on the memory chips. That 2nd bake lasted 2 years and 9 months. So you definitely want to clean off all the old thermal paste after any video card bake.
I've done a second bake last december, the iMac works again :)
How long did your first bake last? And what thermal paste did you use after your first bake?
@@JDW- It lasted about 14 months. The pasta I used was the Cooler Master E2
@@JDW- 11 minutes at 200°C in a convection oven
@@JDW- about removing the videocard, the part which is connected to the motherboard: I found it difficult to remove that small cable, so I just removed the actual videocard from that part, so I didn't have to struggle with the cable :)
You only mentioned having used one type of thermal paste - Cooler Master E2. Did you clean off all the thermal paste including the thermal pads that were on each memory chip? You cannot use regular thermal paste on those memory chips. You either have to use thermal pads or a thermal pad replacement like I did - K5 Pro.
Ok, green lines white screen and now just white screen partial apple line then white. No success in any recovery keyboard option. Imac 27 2011 use less...so I ordered the Geeece grease :) and like you an older dad I am going to give it a go. It looked like way to muck grease until I saw a gap...makes sense now. I will follow up in a week since I am furloughed with this Covid thing I have plenty of time. Thank you for your excellent video and speaking ability.
The two greases from Greece are key! :-) Since my video collection on this topic is extensive, there's not much more I can say except to use a turkey thermometer to verify your oven temperature matches the dial setting. A small number of folks have told me in the comments that they experienced desoldered components. In every case, it seems their oven was on the fritz. It you put a turkey thermometer inside during your pre-heating time, you'll be able to confirm the inside temperature is correct with any inconvenience. Also remember to make the little foil feet, try to make the video card rest level, and bake it with the component side up. Aside from that, it's patience and time. Let me know how your bake goes!
Great video and very informative. Very measured but persuasive. I was a skeptic of GPU baking but there seems to be a mounting body of evidence that this is an effective technique. Thanks a lot.
Thank you, Ian. As an electrical engineer I must admit the bake is highly unconventional and not something you would expect to work. And while I cannot say precisely what is damaged inside the GPU chip, heating it absolutely fixes the problem. Whether it be an oven or heat gun, it will work for you if you have a 2009 to 2011 iMac. Just make sure you use the thermal paste that I recommend. Best wishes!
Thanks! I don’t have one to fix, I’m just interested in the topic. If I get some free time I might see if I can pick up an old 2009 iMac and breath new life into it. I have the ram and an SSD hanging around so it could be an interesting project.
If you find one on eBay with a description that says the screen won’t display anything or the screen is all white or there are screen artifacts or it randomly freezes, chances are it’s the video card. And in that case, the price will probably be very low so you could get a really good deal. If you do get an iMac like that, and if you do the bake,, be sure to comment back with your experience. Best wishes!
JDW I’ll be sure to. Have a good day.
do imac 2015 5k 27'' logic board have liquid filled capacitors?
Inside the power supply unit, yes, of course. But fluid-filled electrolytic take many years to go bad. Maybe around 2030 you can start thinking about that. :-) But the video card in the 2015 5K iMac is totally different from the 2009 to 2011 model iMacs, so you don't have to worry about that either.
You're right. If you have a 9 year old iMac with a failing GPU, what do you have to loose trying this option? It can't get any worse than it is. It took me half a day work to do this repair and my iMac 2011 was up and running again. Compare that to bringing it to a repair shop, which takes a couple of days and (considering the price of a new GPU card) a considerable amount of money. If it fails again, I'll just try it again.
As a note. I twice had my HD replaced by Apple Repair, both times it failed exactly at 3 years lifetime. Every time it costed weeks of waiting and a lot of money. The 3rd time I replaced it myself, this time with a SSD. I think it is now over 3 years and not the slightest show of possible failure, yet. The job was done in less than 2 hours and the cost was less than 25% of what Apple charged me before.
My take on it. Apple has good products, but way too expensive and a terrible service. After it all fails permanently, it is back to the PC again and likely turn to Linux (Windows sucks!).
Thank you for sharing. Your SSD probably won't fail anytime soon. My SSD has being going strong nearly 5 years. It draws less power and puts off less heat than the stock hard drive, which means the internal temperature of the iMac will be a tad cool. I think it will make the iMac last even longer. Once you swap out the hard drive for an SSD, the weakest point of the machine is the video card, even if you swap out for a brand new stock card. Some people have tried some newer MFM cards for PCs, but they require flashing a a lot of fiddly work that most people (myself included) don't want to deal with. They might last longer though. Not sure. Even so, you would be out the cost of the card in that case, and the bake is cheaper. The lowest cost fix is the best fix for these old iMacs in my book.
@@JDW- I agree. It is hilarious in a way that for half a day tinkering and 10 minutes in the oven, you can save yourself hundreds of dollars. Not to mention that the life of the machine is extended for at least a couple of years. Why buy a new iMac for thousands of dollars if this one can do the task too? 80% of the people can work very efficiently with these old iMacs. Maybe upgrade the memory and a SSD in it, and voila! another couple of years fun with Apples.
@@paulvandriel2344 Absolutely. The down side is that folks with the 2012 and newer iMacs cannot easily open them like the 2011 and earlier. The good news is that the newest iMacs seem to have resolved the video card issues. I have a late 2015 5K iMac at the office and it's been going strong nearly 5 years. It has an internal SSD only, not a spinning HDD, inside which makes it fast, quiet and cool. It did cost a lot of money though, which is the downside. Should anything happen to it, it will be harder to service than my 2009 model. But again, it looks like a more robust build.
It will be interesting to see where Apple takes the Mac in the next few years though. The newly released 2020 model is perhaps the last Intel iMac they will make. It's an impressive machine in terms of performance, but knowing Apple will switch to their own silicon means it doesn't make a lot of sense to buy Intel Macs right now. Anyway, it could be that Apple will be able to make Macs cheaper or much faster or both. It's something to ponder before switching back to Windows or Linux in the future.
I baked my card last week. I have a 2011 27” iMac A1312 model with AMD Radeon 6790m GPU. Which I baked @ 390 for 8 minutes. After putting everything back together, Upon turning it on I get the one chime, but the screen is blank and after about 30 seconds the fans go full blast. What did I do wrong?
It’s difficult for me to believe that one or two minutes difference would cause a bake to fail, but my first bake was 9 minutes and all bakes thereafter were for 10 minutes. Clearly the bake did not work for you, but I cannot explain why. Assuming you cleaned off all of the old thermal paste before you baked the card, and assuming you used new and good thermal paste after your bake, you really have two options at this point. The first option is to try the bake again for 10 minutes and see if that works. If it doesn’t work, then your only other option would be to look for a replacement video card on eBay.
Did you try resetting the pram/r ram and the s key at startup or resetting the Memory chips.
I cleaned all old thermal paste off board before baking. Used Artic silver 5 thermal paste before install on all necessary areas. As far as the P Ram , not sure how to honestly. And the Ram, not sure what you mean by resetting.
@@OwensB I am 99.9% certain that a reset of PRAM, a reset of the SMC, and a boot into Safe Mode will NOT resolve your problem. I say this from practical experience, knowing that when you have a video card problem, none of those things can resolve it. Nevertheless, if you deal with Apple Support folk, those are the first things they ask you to try because one of those things can often help resolve a variety of Mac software and even hardware related problems -- just not problems pertaining to a damaged video card. You can try that if you like, as per Apple's support pages here:
support.apple.com/en-us/HT204063
support.apple.com/en-us/HT201295
support.apple.com/en-us/HT201262
If you ONLY used Arctic Silver V paste on your baked video card, it WILL be a problem. The reason is because you cannot use that paste on the memory chips. The original paste Apple used on the memory chips was a THERMAL PAD. But because we cannot precisely measure the gap between the heatsink and memory chips, I personally use K5 Pro, which is a special, thick thermal paste made especially for thermal pad replacement. You must NEVER use K5 Pro on a CPU or GPU though. It's only for times when you have a gap between a heatsink and low-heat chips like those memory chips.
As to your use of Arctic Silver V on the GPU, I did that too on my first bake, and it lasted only 4 months. Arctic Silver V is electrically capacitive, which means any spill-over from the GPU onto the surrounding SMD capacitors will alter the amount of capacitance and potentially cause your video card to malfunction. That is why I used a non-electrically conduction, non-capacitive paste after my 2nd bake. I used K4 Pro because it often comes bundled with K5 Pro. You could use another paste like Thermal Grizzly Kryonaut (the best CPU/GPU paste out there), but you still need K5 Pro on the memory chips.
All said, you may need to remove, clean, do a 2nd bake, then apply the pastes I recommend before your machine will start working again. However, please also note that this isn't a 100% guarantee. It works for most people (see the comments), but not all. If your video card really is on its last legs, further bakes won't help. But sadly, the only way to know that is to do another bake. If that fails, your only recourse would be to get a replacement video card.
I hope this helps!
@@OwensBYou are going to where you would add memory to your computer, open up the bottom of your mac's memory RAM storage is remove any dust that might be there, pull on the plastic tabs to release the memory boards pull out and clean contacts, replace back into computers top slots first ( must have a least one memory board in top slot so the computer will boot. Resetting and testing each memory board to make sure they are still good (a bad one will keep your computer from booting). Taking them out and putting them back in and making sure they are seated in their slot is all you may need to do sometimes to get the Mac booting again.
On my second oven bake. Ok..here is what happened to my mid 2011 27" iMac , I shut my computer down at night (normally I leave it on sleep mode). what I did not realize was my fan speed control software reset to default which is way too slow, my iMac has the GPU heat-sink mounted at the top right hand corner of the case with cooling pipes extending down to the center of the GPU, in theory the fan below the disc drive is tasked with the job of cooling both disc drive and GPU heat-sink...this in my opinion is the design flaw, There is no way that fan mounted near the bottom of the case is going to deliver enough air to the heat sink unless the fan is set at about 2400 RPM. At one point I had readings of over 125.F at the GPU diode, My bake method was 425F temp for 10 mins in the convection oven which fixed the card. I blocked the opening below the disc drive with electrical tape so fan air would travel in a more direct path up behind the disc drive towards the heat sink. My GPU card is currently reading 97.F at the diode and 89.f at the heat-sink with a disc drive fan speed of about 2353 RPM..I just keep watching the fan speeds and temps and so far so good.. i did have the card go out on me prior to all of this with pink bars on a white screen-but I shut down quickly and everything worked again after a few hours..so I had suspicions about over heating.
Russel, thank you for the detailed explanation. If indeed you baked your graphics card at only 225°F (107°C), then I cannot say how long that bake will last. You see, the bake needs to be done at 200°C which is roughly 392°F. Many people who cannot bake with that much precision just use 400°F. That would be about as hot as you would want it to be when baking for 10 minutes. Baking at lower temperatures like 225°F (107°C) may do some good, but I am skeptical if it will last a long time. Honestly, I've never baked at such a low temperature myself, and no one in the comments has reported that either, so I am eager to hear how your bake does over time. Also, what thermal paste did you use after your bake?
@@JDW- actually I was mistaken- I baked at 425.f for 10 mins and used very little thermal paste (Arctic Silver brand) and only on the GPU chip, the heat sink only has contact on that part of the GPU on my machine. I am thinking the memory may not need cooling other than passive air. As I had mentioned the GPU went out on me but I turn it off fast for 2-3 hours and it booted up fine..later I had the card fail again I did the bake method again and found the fan system was running back a default after boot up..anytime I see the temp running high i just set to full blast until I see it at nominal temps. If I do a full shut down I always check the fan settings and keep them around 2500 RPM..also the mac fan control software is a free download and I upgraded to the pro version -but this is the same as the free version so I wasted my money. thanks JDW for your videos..yeah I love my Mac too much to dump it and these machines are too expensive to buy new. My 2011 iMac is still quite powerful with its i7 CPU.
@@tallisrocktube Thank you for your reply. 425°F is 218°C. Hopefully no components fell off at that temperature. That excess heat will definitely take care of the GPU chip problem though.
I used Arctic Silver V after my 1st bake, which lasted only 4 months. The problem with that paste is that it is "capacitive." Any paste that spills outside the GPU chip may touch the tiny surrounding surface mount capacitors, and that could cause issues. But since you used "very little" of it on the GPU, there may not have been much overspill once the heatsink was locked down. Since you said the card failed again after that first bake, I would say it was definitely your thermal paste job, especially because it seems you did not repaste the memory chips.
Fan speed adjustment is important, but thermal paste is extremely important. That is why I recommend either K4 Pro or Thermal Grizzly Kryonaut for the GPU and K5 Pro (a thermal pad replacement paste) for the memory chips. If your graphics card fails again, I would try that kind of repaste. Even so, it's important to keep in mind that you cannot keep rebaking those cards forever. In my case, I got 4 months of life from my 1st bake (due to my inadequate thermal paste job) but then I got 2 years and 9 months from my 2nd bake, and then my 3rd and 4th bakes lasted only 1 week, so I gave up on the 4850 card and bought a 6970M, which I continue to use to this day. Best wishes!
Hi JWD, i have an 2011 27" IMac, 12,2.
3.1 Ghz Intel Core I5
(8*2) 16 GB 1333 MHz DDR3
AMD Radeon HD 6979M 1024Mv
High Sierra.
It's have random screen freeze issue whenever what software or work I'm doing.
it's just freeze at where i working at and all the mouse and keyboard will not work.
I have to hard/physical shut it down
May i know i should change the GPU or graphic card in order to solve the problems?
Based on what you told me, you would either need to bake your video card as shown in my videos or completely replace the card. The CPU doesn’t have anything to do with that problem.
@@JDW- got that.
Thanks for your advice.
So i had go through your video, it's need K4 and K5 pro for the GPU, is that right?
Correct. I put all details and links in the text description.
@@JDW- thanks alot
Thank you very much, My iMac is alive
Thank you for making time to let me know your success, Justin!
Thanks for the info.
I always heard its a very bad idea to use an oven you are going to cook food from later due to the wide range of chemicals that come off these electronics when you bake them.
The temperatures we are talking about in this bake are not hot enough to completely desolder components and therefore you’re not going to have smoke from residual flux nor any significant airborne chemicals. There were no bad smells at all after either of my bakes. My last bake was 2 1/2 years ago, and I and my family are currently in perfect health. If one is worried, one need only wipe down their oven after the bake. If you are still worried, then you could try the heat gun technique although that would require a bit more skill to ensure you do not completely desolder any of the components.
You can do the same fix in 5 minutes with hot air blower by putting the iMac on it's back on the floor (display up) and blowing hot air through the bottom right side vents and turning iMac on so that the fans will distribute the hot air to the GPU. That way the processor of the GPU will fasten again to the circuit board because of gravity. :) I did that baking thing 2018 and my 2011 iMac worked almost two years without any problems but now tried this easier and quicker method and it worked right away. Hope this tip saves someone's time and nerves.
I certainly welcome all new ideas to repair defective video cards. However, your suggestion does merit some level of open-minded scrutiny. First, it would be nice to see a video showing clearly what you have described. Based on your text description, it would seem that the "hot air" (at what precise temperature you did not mention, and that really is key) would hit more than just the video card and the repercussions of that are unknown. Indeed, you are the first person to ever suggest this trick. The long term viability of your technique is also unknown.
Prior to doing even my first bake, I spent a lot of hours checking experiences of others, which included watching TH-cam videos and seeing how long these folks were getting from their method to fix the video card. After being satisfied with stories of longevity, I decided to try it myself. And after a few years, I think we've established that the bake really can last long enough to make it worthwhile, and it does not have ill effects on other components inside the iMac.
So while I am not saying your method is wrong, some people probably will naturally want more information before trying it themselves. As such, I would encourage you to make a video on the subject and then keep people informed about how your video card does over time. That's pretty much what I've done with all my videos on the subject of the video card bake. Thanks!
Bad idea. You do not want heat components other than problem which is GPU. Heating through vent will risk damage to the LCD. Removing the GPU gives opportunity to renew the old thermal paste which is likely dried out and ineffective. Don't be lazy. Do it the right way.
@@encinobalboa I changed thermal paste 2 years ago so it's not very likely dried out. I don't know the temperature of my hot air blower but I kept it 40 cm away from the bottom vents for 5 minutes. The fix worked only a short while and I'm going to try it again soon as I'm too lazy to get the GPU in the owen this time.
@@livescape9115 Lead free solder (the crap AMD uses in the 6970M) melts at 217C which is why bake is 200C. We want to control heat so solder re-flows in place. You would have to apply much more hot air than 200C to reach the GPU through the vent. In the meantime, you will be melting the plastic in your LCD. We can do this your way or the right way.
@@encinobalboa OK, I see. I'm just too lazy to do the baking second time. In a local Apple repair store replacing the GPU would cost 900 euros that is way more than the price of the 2011 iMac in the aftermarket. Maybe I try to set up my nerves to stand that baking process again.
Happy new year, again. Last time I which you happy new year I was living in the past. Because you live in Japan (Bad joke from the Nederland)
Hi JDW, last night i see all yours baking videos (with subtitles, because i'm italian and when you talk fast i lose some words). This Sunday i will try one similar thing with an Imac 27" mid2010, because now we have only magenta and pink vertical lines on screen, without the Apple logo. Just the initial bong. No safe mode or recovery allowed. With my son will do a video of the experience. It will be different fom your because we will use a technic phon and not a oven (my wife doesn't want !). I will concentrate the hot air on GPU and, if it works. i will do a secondary operation changing the termal pad with your K5PRO. For the moment i will use only my Artic Silver AS5 on the GPU and heatsink. With this pandemic problem all shops are closed and the online is very slow. We have to stay at home, so we will spent our time with this experiment. Thanks for your videos ;.) My problem is here www.imaccanici.org/forum/ucp.php?i=pm&mode=view&p=30600 Best regards
Grazie per aver guardato! È molto importante applicare circa 200 ° C alla GPU. Applica quel calore per diversi minuti. Un asciugacapelli potrebbe funzionare, ma mettere un foglio di alluminio sulle altre parti del circuito stampato in modo che solo la GPU ottenga la maggior parte del calore.
Inoltre, assicurati che ArcticSilverV sia nuovo. Non utilizzare la pasta termica di età superiore a 1 anno. ArcticSilverV è "capacitivo". Pertanto, si prega di applicare solo una piccola quantità al centro del chip GPU. Se si applica troppo ArcticSilverV, la pasta termica in eccesso si spremerà e potrebbe toccare i condensatori circostanti. Ciò potrebbe potenzialmente causare problemi.
Dopo aver finito, per favore fatemi sapere se avete avuto successo.
A proposito, non parlo italiano. Spero che Google Translate abbia fatto un buon lavoro su questo!
-------
Applying approximately 200°C to the GPU is very important. Apply that heat for several minutes. A hairdryer might work, but put aluminum foil over the other parts of the printed circuit board so that only the GPU gets most of the heat.
Also, make sure your ArcticSilverV is new. Don't use thermal paste older than 1 year. ArcticSilverV is "capacitive." Therefore, please apply only a small amount in the center of the GPU chip. If you apply too much ArcticSilverV, excess thermal paste will squeeze out and possibly touch the surrounding capacitors. That could potentially cause problems.
After you are finished, please let me know if you had success.
By the way, I don't speak Italian. I hope Google Translate did a good job on this!
@@JDW- Hi JDW, today I have tried two times to reflow the graphic cpu... but I have lost my battle. Same vertical lines and no boot.
So I need to find another graphic card like mine (Radeon HD 5750 1GB) or try an upgrade to a model from mid2011, like Radeon HD 6970M 1GB. Is it 2GB your upgrade ? Last chance, sell any part off the iMac. Thank you and Best Regards.
@@cristianomarchi9525 Please see my newest video about the 6970M I just installed, and be sure to then read my Pinned Comment in the comments section for the caveat I discovered last night. th-cam.com/video/9dPsH1zIQMs/w-d-xo.html
is it still working?
As mentioned in my 3rd bake video, the 2nd bake lasted 2 years and 9 months: th-cam.com/video/teV_atLUlpM/w-d-xo.html
But my 3rd & 4th bakes only lasted 1 week, telling me the card could not be baked anymore, so I am now using a 6970M, which has been working almost 2 years now. For more info on that and all my bakes, please see my Playlist of videos here: th-cam.com/play/PLNZ4qjMn-GHoez6_PtpyJfcU_ialTS8bB.html
4/18/2020 Just watched your Bake 2 video have the same late 2009 27" iMac with all the same issues of not booting except in safe mode and the horizontal lines, bad design for the GPU card. Glad to see this response video instead of having to read through all the comments. Need to get the thermo grease 4/5 from Grease before I try the bake and I agree that in 2020 that the 2009 27" iMac is quite useable with OS High Sierra installed on it. Question I still have is how hard was it to reconnect the temp cable back on the motherboard after the repair? Hate to loose the use of a perfectly good Mac as my daily driver.
Reconnecting the tiny 2-pin connector to the back of the motherboard (a connector that leads to the temperature sensor on the video card) is difficult if you don't partially remove the motherboard to pull it forward enough to see the mating connector on the motherboard. However, I have enough experience at it now that I can, with a fair amount of trouble mind you, get it connected without removing any motherboard screws. Practice really does make perfect! But for you, I would suggest leaving most of your motherboard connectors intact, then remove most of the motherboard screws so you can see well enough to get that little guy into its mating connector. I would also suggest using fingers instead of a tool to ensure you don't accidentally rip one of the wires out of the connector or otherwise do accidental damage.
You should upgrade your card with Nvidia Quatro K1100m or K2100m. You'll have metal support, brightness control, you can run Catalina with dosdude1 patches and there will be no overheating.
Thank you for your suggestion. I have a reasonably working 6970M right now so I lack the incentive at this time to try another video card. Flashing the card you mention either requires a Mac running Windows in boot camp or a true Windows PC, neither of which I have setup right now. If and when my current 6970M fails, I will of course investigate the cards you mention and make a video on that experience at that time.
@@JDW- You can flash your new gpu from Linux. Here are instructions and all files you need:
th-cam.com/video/0b_YzIjOvOE/w-d-xo.html
I appreciate the tip, but we are a Mac-only household. I’ve used Macs exclusively since 1984, in fact. And while I have some limited experience with Windows, I have zero experience with Linux. Even so, your tip will be of help to others who may have experience with Linux. Thank you.
When Apple stops supporting High Sierra, we will have to upgrade GPU to stay current. Should be a couple more years before then.
technically, I’m not current now seeing I still use High Sierra. :-)
It is work for me thanks for your video
Thank you for making time to let me know your success, Anatoliy!
My iMac seems to have a failed gpu now. So I need to bake my gpu. A little nervous... not going to lie.
Unless you intend to also replace the button cell battery too, I would recommend you follow my 2nd Bake video. Be sure to buy the required two types of thermal paste I recommend. And to give you further peace of mind, put an oven safe thermometer like a Turkey Thermometer inside your oven during the warm-up period to verify that your oven's temperature dial is accurate. If it's too much more than 200°C or 394°F, components can become desoldered. Most people don't have issues, but a handful of folks with problematic ovens have reported desoldered components, which is why I recommend verifying the temperature to be 100% sure nothing will go wrong during the bake. Be sure to make the aluminum foil standoffs as I recommend, then bake for 10 minutes. After that, leave the oven door open and let the card cool to room temperature, repaste, reinstall and test. Also be absolutely sure you clean off all the old thermal paste before your bake, not only on the graphics card but also on the heatsink too. If you still have doubts, I would encourage you to read through some of the comments under my 2nd or 1st bake videos. I read and reply to every comment. Most people who try the bake have success. Good luck, and please let me know how it goes!
I don't get them people who bash people for baking their stuff, I mean its broke, what do you have to loose? Bake that sucker, if it don't work, it don't work.
Exactly! Thank you for your kind words and support!
My second bake just died after about 3 more years. Here’s to the third try. 🤞🤞🤞
A bake that last three years is pretty good. But fingers crossed that your next bake will last just as long!
Legend ✅ thanks 🙏
Let’s bake some GPUs
Hi there, it's me again after 8 months. I finally replaced the GPU and the iMac works perfectly fine with an external monitor, but the internal stays black.
I can't see anything using a flashlight, three diagnostic leds are on, 4th is off.
The internal display is not shown in "about this imac", only the external one.
Also, the v-sync connector plastic shield is broken, but all 4 pins are fine and the cable is seated tightly. I read that display should work even without the v-sync cable connected, so I don't think this is the problem.
Options are:
- broken LCD
- broken ribbon LVDS cable (i broke the original one and replaced it, but the new one could be damaged too, idk)
- broken LVDS connector (but it looks fine to me)
- something else on the logic board
Any other ideas? :
I'm sorry to hear that. When lit, LED#4 shows that the iMac's motherboard and LCD panel are communicating. LED#4 should be ON when the computer is turned on and video signal is being generated. It's only when LED#4 is ON and there is no image on the display, that the LCD panel or LED backlight board or the cables between might be installed incorrectly or need replacement.
Because you are never seeing LED#4 come on, Apple has the following advice...
• Verify cable connections between LCD panel and logic board
• Inspect LCD display cables for cable damage
• Verify external video functionality, and according to result check the following items:
-If external display works then verify/replace the LED backlight board -If external display works then verify/replace the LCD panel
-If external display does not work verify/replace the logic board
I would say just buy a new GPU, but even they're prone to cracking, it's just bad hardware design on Apple's part and inadequate cooling that causes the actual dye of the graphics chip to crack with heat stress.
I later did buy a different graphics card, and I made a video about that at the following link, and I’m pleased to report it’s still working to this day in May 2024.
th-cam.com/video/9dPsH1zIQMs/w-d-xo.html
@@JDW- fair enough
It’s such a stupid idea, that it actually works.
Amazing but true. It really does work. It doesn't last forever. But then again, what repair does last forever? :-)
Hi, My Apple Imac 27 Inch Crashing Randomly, Going in boot loop,Getting Vertical Lines, Some times Green Screen, Some times blue.
I try all solution. Safe mode, Recovery, Reinstall OS,Re install Old OS, Install Windows... Went through million solutions and forms to make it work
Only reflow GPU card solution work.Open Imac take out graphic card,Clean & wash properly all thermal paste, Heat Oven 200 C. Keep GPU card on small Aluminium balls, Keep in oven for 10 minute. Let it cool for 30 minute, Get new thermal paste not conducting electric type apply small amount on GPU & all other black component jut like doing painting . Do not apply thick layer.
Just enough to cover. Like paint on wall. Tight all screws properly firm & reinstall card. It works 1000%. I have wasted many week & spend lot of money.
All the best.......Thanks
Thank you for sharing your success story, Nehal!
I propose you attack the ROOT CAUSE of the Over-Heating GPU.
Although my 1st Bake lasted 3 years, my 2nd Bake failed and I started to think more about why is the GPU failing in the first place.
I believe the Thermal Design on the 2011 iMAC EMC2429 is a total Failure (ODD FAN air-flow goes under DvD/CD drive to finally get to the FINS( 6" away) to the 3-pipe L-shaped GPU Heatsink.
History:
1st Bake Mar 2017 Pass,
2nd Bake May 2020 Fail.
3rd Buy used GPU card on eBay, advertised as Tested Good.
Proposal:
1). Propose removing DvD/CD drive and install a new USB Blower Fan (AC Infinity MPN: AI-MPB140A) 35 cfm
in the same location (which is very close to the actual GPU)
2). Remove 3-pipe L-shape heatsink and install a standard Heatsink ( MXM-type B) (max pwr 200W) Heatsink w/bracket for AMD 7650A
3) Install a thermal sensor cable to the new Heatsink.
4) Remove the existing ODD FAN as it has NO USE in the new approach (new USB Blower Fan blocks air-flow from this existing ODD FAN.)
I need HELP in finding an appropriate HEATSINK and THERMAL SENSOR CABLE......still looking
Found this Heatsink w/bracket for AMD 7650A on eBay.
Thank you for sharing such detailed thoughts. My newest videos on this topic talk about the AMD 6970M that I purchased and am currently using. You may wish to watch those two videos for all the details of what I have done and what is going on now. But as to your proposal about removing the optical drive, using a different heatsink and fan, that would be an interesting mod, although the average iMac owner really wouldn't have the ability to do all that, I don't think. Many people have been reluctant to do the bake, but they manage it because my videos show them everything step by step, and it's not really a major mod of their hardware. Even so, if you ultimately do the mod you propose, I strongly suggest putting your iPhone or another HD camera on a tripod and filing every aspect of your experience. That info would be useful for others.
Lastly, it seems you were going to post a link. That's perfectly fine. I don't block links. I do think you forgot to post the link though. I honestly do not know what thermal sensor would be compatible. That really is key to getting it to work with the iMac. I've never measured the signals going between the motherboard and the heatsink thermal sensors on the 4850 or 6970M. That information is crucial though to knowing what sensors would work.
@@JDW- it looks to me like the existing Thermal Sensor Cable can be removed from the 3-pipe L-shaped Heatsink, if you can remove the Copper Shim on the opposite side? So I plan to use this existing Thermal Sensor Cable on the new Heatsink.
@@ptbuber5027 Removal of that thermal sensor is probably easier than getting it properly reattached to a new heatsink.
@@JDW- 1) to move DVD/CD drive outside the case. Drill larger hole in bottom of case to accommodate the extension cable for the DVD+/-RW Drive.
here is the cable description> 50cm Length Slimline SATA 13pin Male to Slimline SATA 13pin 6+7 Female Extension Cable for SATA Slim DVD+/-RW Drive.
www.amazon.com/Length-Slimline-13pin-Female-Extension/dp/B078J2VQMP
@@JDW- th-cam.com/video/3i8ohwZnBpc/w-d-xo.html
Thank you for the instructions! I fix one iMac (27-inch, Mid 2011) with this technique. Card to the oven with 200°C 10min and K4 K5 thermal paste etc. Everything works fine now! I have a bit newer model, so removing the graphics card was harder, and I had to touch the motherboard. Here is some idea how to do that part: th-cam.com/video/hRtB6VBDiSU/w-d-xo.html
Thank you for your kind comment and for the link. As you can see in that video though, there are issues you must deal with when trying to use non-stock video cards. That is for serious enthusiasts rather than most people, which is why I have not yet done a video on those cards. For most people, the bake tends to work at a low cost. And I think cost matters because most of us are trying to resurrect computers that are 10 years old. And while some PC cards are rather cheap, time is money, and you really do need to spend a fair amount of time flashing and doing things to get non-stock card to work properly. Even then, there could be certain OS incompatibility issues to deal with. That is why I am content to use the 6970M in my late 2009 27" iMac for now. A higher fan speed combined with room A/C switched on keep the card running cool enough to where it is perfectly fine now as a daily driver.