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- เผยแพร่เมื่อ 14 ก.ย. 2015
- After repairing the melted connectors on the processor board, will the dumpster dive Samsung LCD TV work?
A quick follow-up video to this disaster:
• EEVblog #782 - The Dan...
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Surrender is not an option, please make it work again.
+Dorf Schmidt This TV set is FUBAR
+TheBadFred Indeed, time to follow in the footsteps of Bob Pease and chuck it from the highest available rooftop and see if that does not fix it!
I do miss him as he was such the character and so much fun to watch.
+Dorf Schmidt In my experience, it's often the main board, followed by cables, followed by t-con board. Sometimes, it's just in need of a firmware update. Those are fun when you don't have wired internet access and have to use your cell phone as a hotspot and have 1 bar of service.
Because of the way the lines slowly appear, i bet it because something heating up..
Try using thermal camera to see if there is some single component that heats up at the same rate as the lines show up.
+NuffMan heating or ... charging .....
+NuffMan that actually does make sense...
+NuffMan Wouldn't the thermal spray be a simpler approach to thermal issues?
That makes sense, but didn't he blast it with freeze spray before? I would think the lines would have faded at least a little. Maybe he didn't hit the right component. He's got the FLIR, this would be a perfect application for it
Darn.I so wanted to see it fixed.
That was fun.Thanks.
I find your videos very educational and fun, brings back enjoyment with electronics ;) Love them!
What does it look like with a video signal applied, as opposed to just the OSD?
+James Lamb I agree--maybe it's just a problem with the text display!
Gate open driver voltage on t-con board!111 dc-dc converter on t-con!!111
+FutabaGP voice of experience I hear ???...I agree, I have corrected this type of problem several times before and its usually the t-con board.
+FutabaGP whoop whoop - send in the crash cart and GET IN THERE DAVE ! COMPONENT LEVEL REPAIRS PLEASE
+FutabaGP Good Idea!
+FutabaGP Got a schematic for the board?
+EEVblog unfortunately no, as far as i know there is no schematic for this particular board.
It's great that you stuck with it and tried to repair it, I find those videos very interesting. Hope more for the future.
Pretty sure its a tab bond issue still. top left one most of the time is the cause. bend that part of the frame with out pulling it to bits usually works..
As per the discussion I had on the last video, its probably not the panel, but I would have liked to see the main video processing chip get his with some freeze spray at the end :D, IIRC I had an Akai 21" LCD do that many years ago, the Genesis display driver had gone bad causing red lines like the ones you see to flare onto the screen as it warmed up, I hit it with freeze spray and they almost disappeared. but as you said, without finding the exact source of the problem , it can turn into an expensive parts swapping exercise!.
+Aussie50 I froze the main processor and it's memory several times in a previous video.
+Aussie50 Hey, Ed. ;)
How's it going with the Flight Recorders?
Are you planning on extracting the audio from that recent tape, or recovering the data from the Fairchild FDR?
As for Dave's LCD, I think it's probably the TCON driver itself, personally.
It could be one or more of the Chip On Flex drivers though, as I had a similar thing happen on my Samsung (bad solder / bonding on the flex chips.)
+EEVblog I think someone linked a video of someone fixing this through the service menu.
+EEVblog are you living near aussie50? You could bring him this bitch and fry it with some MOT's
+gamerpaddy They live about 14 hours drive from each other...
It was fun following along the troubleshooting steps, I must learn the basics behind electronics repair some time...
congrats on it living again, now please, check signal connections and feed it some video without the graphics onscreen. Just curious, it never gets that far.
Thanks for the follow up !
There are other videos on youtube explaining a software procedure to get rid of the artefacts. Search for: Samsung tv vertical lines fix
Good lessons were learned in this video series
Don't give up on it please
Based on all the videos on this, I'm almost certain that it's the PPU that's bad, possibly the line/framebuffer RAM at some stage in the image processing pipeline (stuck bits that end up accumulating from previous frames and previous lines).
Wow dave, i really thought you would of tossed it after the reflow incident. Took it further than I would have xD
Ahh well, least you gave it a shot! And definitley learned something from this! Not all electronics plastics are high temp
Thumbs up for the desoldering! I always mess something up when I do that.
Don't surrender! I want to see this LCD fixed because of reasons!
Wow, you guys try it quite hard to get this puppy running. I wonder what is the next trial. And you know: Never ever give up!!! :-)
+eevblog Hi Dave and Dave2. Thanks for giving us another (final?) update on the Samsung TV dumpster dive repair. One question. I watched the other vids and looked through the comments, but is the striping problem visible on all the other inputs? All HDMI, Component, Composite, etc.? Or is it limited to VGA? I need to know! :P Thanks as always!
Try doing some circuit bending on it ... figure out what signals are analog and digital and start crosslinking stuff that won't fry. It could be interesting to see what kind of crazy stuff you could make a panel like that do!
well, at least you got a bunch of free content out of your dive
Curiosity, would you find anything indicative of the issue on the oscilliscope/logic analyzer if you checked the cables that drive that section of the TV?
Seems to be fine for a brief time when powering up. Maybe try some freeze spray to see if you can locate the part that is getting warm? Just a thought...
It is quite odd how the streaking only affects character generator output. Graphical UI elements like window borders both horizontal and vertical seem perfectly fine.
+Teardown Dan oh shit, I was busy thinking about how the lines slowly appeared that I didn't even realize that it was just on the text... weird now I'm not sure what the problem could be.
+bmw2go11 Possibly, but then what are the odds that the previous owners threw out a fairly new LCD TV *just* because the OSD was messed up? If they are like many viewers you almost never see the OSD in operation save for very briefly when adjusting volume.
Then there was the additional issue of every other horizontal line messing up as well, if I recall correctly. It is behaving a lot like a capacitive charge building up without ever discharging the way it fades in so smoothly (and seems to be immune to freeze spray so probably not thermal in nature).
Ethan Poole My guess would be some form of error in the image processing code or DSP. I could imagine the vertical streaking being caused by an IIR filter having the wrong decay coefficient and not being reset at the beginning of each frame, causing it to accumulate a persistent bias. As for why it seems to only affect the text overlay, maybe the graphics overlay is exempt from the filtering while the text overlay isn't for some odd reason.
Maybe the display/UI controller simply has a corrupt firmware image with a few flipped bits.
hi Dave can you power up just the LCD backlight so LCD is powered but not getting data to see if the screen is OK?
Could the problem be temperature related?
Maybe the stripes only appear after a component(s) reaches a certain temperature. If thats the case, im curious which component(s) may be the culprit(s).
Since the issue occurs around the ASCII characters, does it work fine if you have an input connected?
I.E. If you plugged in a computer or external set-top box would it work fine for those purposes?
Hello, I have a question:
Is it recomended to reflow connections on boards with a hot air gun? Like if i put a PCB in the oven I can reach a max temperature of 250°C but with my airgun it can reach up to 580°C. Would the heat damage SMD´s?
I ask since i salvage lots of parts from old electronics via heat gun but never thought about parts getting damaged.
did you check the ribbons for the lcd panel at the top and bottom?
Since it comes gradually, I would use cooling spray and go through and cool all components until you find the culprit.
+Magnus Arvidsson I think they tried that in earlier videos
It appears that the stripes line up exactly with the ascii characters generated by the panel. What if you put a signal into the panel, TV, PC, DVD... whatever. Will the lines disappear as there is no on-board generated characters then? it may still be usable in that case.
Now for the part 4, where you begrudgingly take out the t-con board and try to troubleshoot it.
Very interesting videos! And Samsung, at least here in the USA, is thought of as the #1 HDTV brand! And yet this thing didn't even last a decade! That's scary!
Could that artefact be due to memory failure? If the colours are always the same at each position across the screen then that would suggest a fault in the display memory. Probably be a PITA to replace surface mount memory, though, so likely not worth the effort.
please do more dumpster repairs.
Just a wild thought :
What if you use a thermal camera towards the PCB and another regular camera towards the display panel.
Boot it up, and cross check the two recorded videos and see which chip heats up in proportion to those discoloration showing up on the panel! :)
You would then find out which one is most likely the culprit.. ;)
This looks like a TAB BOND issue, I've seen many samsung as well as other brands that have this problem......
If you press on the ribbon cables that feed the LCD display from the feeder boards, you'll prob. see those lines jump on and off.
Check those ribbon tab bonds from lcd panel to the feeder bd's.. !
Are you sure it isn't a software problem ? The stripes only happen along the letters so that is really weird .
Ow no. Don't give up!
Here's strange suggestion, what happens when you give it a video source? Does the image still look bad? I think this has to do with the OSD.
my guess is a on film ribbon ic from the driver board to the screen,had this problem.check it to see if its getting hot?iv tryed heat sinks with compound lasted the longest but the fault still came back to haunt me, Murthys Law lol
I'm afraid that in such cases normal reflow temperature just won't cut it..I followed the most common temperature profile on my nvidia gt650m and didn't work until I brought the temperature right up to 300 Celsius! (heat gun and multimeter, several attempts, using no clean flux). since it's lost anyway, you might want to give it a try...
EEVblog! You are not getting off that easy. We know you can do it. Now fix it right!!
you have to fix it now!
feed the TV a VGA-signal or switch to a digital input see if the high contrast edges still produce them stripes
Love the video Dave 6 Dave you guys are always so funny!
I know these kind of faults are the tricky ones to find...
So instead of throwing this away, cant a crowdfunded repair be kind of fun?
- like if someone has the tcon board laying around to try to swap it and see if the faults is going away?
Me personally i think the tcon is bad, can you extract the video signal from the systemboard and see if it is ok back there?
And yeah a schematic is what you need too hope someone can give you access to it, so dont give up on this repair i know you like challanges dave1 so
keep on dealing with this and see where you get? :)
Hey mate. Need help from central qld... logitech g27 motherboard fault. can't identify what the fault is can you help?
What'd up with the CNC build?
I'd love to see you do a component level repair on this. I'm sure you'd get the youtube views to make it worthwhile. I think its actually the most interesting series of videos you've done and that's comparing to some other pretty damned good videos.
I was expecting Dave to 3D print the connectors out and chuck it in again.
just try push place on screen in corner flex where signal goes from vertical to horizontal drivers. i wrote a comment in first video.
+snik2pl the same thing was with sony KDL series. Shame that Dave have theoretical knowledge but don't have practise in tv repairs
Bugger, I'm sure you'll get it working one day :)
Great attempt though.
We've enjoyed all the videos. Too bad it didn't work.
It's a well known common fault that certain sizes of Samsung screens have that fault with the panel is the bonding onto the glass.
TV vs Dave. TV:1 - Dave:0 I want to see a rematch.
It seems like a MSB shift somewhere between the caracter generation and it's overlay. It only happens on SOME of the text, but ONLY in the text. Something analog, with a linear behaviour over time (heat?) is crosstalking and contaminating digital outputs. A faulty decoupling cap along character generation ground reference is my best guess.
It happens everywhere there is text when it has run awhile (as seen in earlier videos), though the degree of intensity seems to vary with the color of the text making the red stripes in line with the "PC" text stand out most of all -- some pixels seem to "charge up" more quickly than others depending upon color of the text (almost as if a memory cell capacitor is slowly charging and never discharging). But, if I recall correctly, there is also an issue affecting every other horizontal line as well when you get a closer look at the screen.
+Ethan Poole and upon closer look, only characters with a vertical pixel density seem to generate lines. look at the time --:-- only the collum has the red line
It's not the panel. I've had this same thing on a Samsung. After a month of debug (from time to time) i gave up and bought a cheapo Chinese replacement kit that worked for the panel i had. I replaced all the shitty parts on that, put bigger heat sinks and reflowed all the solder and it's working perfectly now.
At this point of giving up I'd just film myself having fun smashing it. Photonicinduction style.
not so bad. it's like watching tv with the dog standing in the way
At least you have sometimes luck with the "reflow oven" *cough* :D
Maybe you need to plug in some batterisers? ;)
Measure while it "heats up", see what's different before it gets the lines. That heating looks suspiciously analog to me, like from a power problem from capacitors.
Iv watched videos of people who do component level repairs who say reflowing is basically a myth and have showed that the solder balls do not melt and reconnect. Now i'm confused that this is what you attempted to do...
Please try some actual video input, not only menus.
I am considering buying a new LED TV, and I am concerned about build quality, and reliability, among Sony, Panasonic, Samsung, LG, and Vizio... Who do you think would be good choice... Like the vids... thanks
Dave, have you tried to switch it off and on again?
:D
well that sucks. what bad luck. o well good job guys
check negative voltages at que panel board
I would still use that screen in my office to monitor our network
Can't win em all! Better luck next time! :)
That TV is becoming a little bit of a pain.... next job get one of those meters out and make sure the chips on flex are working like they should be... that's my thought line anyhow... +EEVblog
Give it to the professional TV workshop :) It's too big deal for you guys :D
2:44 oh, a Realtek part... Didn't know they used those for TVs, they are usually pretty garbage level audio and network chips in PCs.
+Nukle0n Ahh, Realtek. In literally every motherboard ever made...
I'm not sure why people are commenting to analog problems. The menu and display are going to be purely digital. Use the scope and find the stuck bit on the bus.
It's upside down, and all the bits are falling off. There's your problem.
+WarpRulez no, it's right-side up. learn to australia!
+Sudos The bits are attracted to magnetic north so hence float upwards. of course if you are in the Nothern hemisphere, the bits can't go north so will end up heading south or down. For those that are on the equator, please let us know which way the 1s and 0s head.
gorillaau
The positive magnetic pole of the Earth is near the South pole. Therefore electrons will be attracted towards the south.
+WarpRulez electrons are not attracted to magnetic poles but deflected in a right angle by the magnetic field...
Dave, could you do a episode with Aussie50...please???
it's interesting how the lines don't appear right away, it's not until the TV warms up they are visible, and they become more prominent as it keeps running. Must be a thermal issue.
+MichaelKingsfordGray yes maybe a bad cap.. The panel i think isn't broken.
Never mind dave, you gave it a good go mate :-)
Yank any usefull parts and send it home to the bin lol.
Cool ideas for the connectors :) I wonder shall you throw this piece 'o junk away this time, or still insist trying to resurect it:)
i don't see the panel as the problem, chase the idea of the t-con board personally, as when you fired it on, for about 20 seconds, there was NO lines, you didn't mess with heating the panel, just the boards, yet for 20 seconds NO lines, in my opinion, you would have immediately seen an issue in the panel so technically, i suspect one of the chips on the t-con board also, and possibly 3 or so solder joints to make them work aren't connecting properly
Is the lcd broken
the way those lines charges, there's must be a leak somewhere. either a resistance (heat) or capacitive (heat or just some faulty component) problem.
I haven't seen the schematics, but it has to be near the output circuit and definitively in the vertical circuit.
EDIT:
saw a comment that pointed out it's only on the text...though why not L, - , i or the first part of h and k, that's just weird.
buffer problem? now I'm just guessing, I have no clue R.I.P tv you were worth a try.
just bought a 42" Philips Lcd TV for 30€ it works fine but it always takes two presses on the power button to come on. Power Supply looks good and gives the Voltages it should...i guess ill just use i as it is...
+EEVblog Finally back to work. Excellent! The hunt is back on! Please find the fault. Remember!
In all the labs, at all the benches and at all the solder irons!
Never surrender!
I really uspect a TCON voltage generation problem here.
A lot of samsung TVs have Dodgy connectors to the HDMI/inputs.. Try giving them a jiggle/bang.. you never know your luck :)
dam you guys need to fix it ok keep going find out whats wrong with it :P
Bugger!
It goes to show why it is cheaper just to buy a new unit rather than trying to have an old unit repaired.
+gobblox38 Sometimes, yes. If all you have to do is replace a 50 cent cap, repair the fucker.
If you know how to do that, most people don't and would have to pay someone that knows how to.
gobblox38 Most people should learn some basic freaking electronics. Seriously, inside of a week prettymuch anyone can learn how to replace caps, even if they've never seen an electronic device before.
The problem with saying that most people ought to learn a certain skill is that most people would rarely utilize that skill. Unless it is a hobby or part of your profession there really is no use in learning it.
+gobblox38 manufacturers realized we're fixing our own stuff by replacing capacitors. The timed faults are now in the chips themselves
Can anyone else hear that low-ish frequency hum in the background? It's definitely the video as I pause and it stops, nor does it occur with other videos.
I have heard it in other videos and realised that it probably has something to do with the led illumination drivers because in said videos Dave turned those light off and the sound stopped. Maybe it's coil whine? maybe the mic is picking up some of the supply switching noise somehow?
+RapiBurrito Transformer hum perhaps. Probably just EMF leaking into the mic tho.
+Richard Smith Yes, it is very easy for microphone leads to pickup stray RF/EMI, especially if it is just ahead of the audio amplifier or preamplifier and even more so if it is a high impedance microphone. In my experience it is often an even greater issue when the cameras have (some degree of) a ground reference due to being plugged into the mains rather than operating on battery alone.
My toshiba regza 2010 55 in 3d tv has the same problem
i Worked at Samusung earlier, and i know exactly where the fault is :)
"Samusung" -- is the that one of those Chinese knockoff clones of Samsung, where they just can not quite seem to get the brand name correct? Like a "Wakko" soldering station?
Sorry, I could not resist as those not-quite-right knockoff names always amuse me and that is what popped into my mind!
+Ethan Poole. Exactly! I did also work for Sammsung and Samsungi!
Eh, im sure if you watch a tv show on it you'll eventually forget about the lines and get used to it....maybe.. :X
You should try a firmware upgrade, if it is available. Maybe just a software issue...
If it is only ascii character that are do line, why not Turn it on, with monitor cable plug in, and the Text is only on screen for about 2 second, then it go away, so the lines not appear, and you can use it as monitor!
No chance of moisture or residue???
Probably the panel, time to turn it into spare parts... :P