Sorin, I've seen similar on graphics cards that are not short, where you have all power rails present and correct, the clock is running and the reset is off, all resistances read OK but the GPU does not start (does not attempt to read BIOS). With a high resolution thermal camera you can see dark/black patches in the GPU die itself where the silicon seems to be 'dead'. You can compare this with a good GPU of the same type by forcing PCI_RST low so neither GPU are starting, if you don't see the same heat signature pattern in both GPU you most likely have a dead one. A hi res thermal camera with macro lens is an extremely useful thing. Have a play around with your camera looking for cold patches as well as hot ones. 😉
Thanks for your videos, I love watching how you diagnose faults, all beyond me., I can just about solder wires on my Model Railway. But we all have our different skills I have been building my own computers now for over 15 years starting with a AMD Athlon, up till recently with a Ryzen 5 5600X. Keep up the good work, good luck with your new site too. 74 year old pensioner here, Chris
You're gonna have a faulty CPU if your highside FET fails before the lowside, i think, and you have 12V-20V sent to the CPU. Or if you have feedback circuit trouble or somesuch, sometimes a good whack can have unforeseen consequences. CPUs are highly reliable semiconductors but not very robust!
Yes,it is....I own before MSI K8N Neo ....Bad capacitors blow my CPU :D CPU just heat and heat like crazy but nothing more But today motherboards use better capacitors so IDK how is possible kill CPU Just overvoltage like lunetic :D Otherwise IDK
Hint, most cheap lenovos from 2013 and later. MB lack any protection on ports thus I have seen many 4th gen and higher CPUs with blown up PCH = CPU dead. With my experience I would say 99.9% boards with shorted vrms have dead CPUs, confirmed with tests. Same for desktop GPU's. Blown VRM = don't even bother, chip is long gone. I bet someone reply to this that it is not a rule. Well at least it's just my own experience. Non dead chips after mosfet short? Happened, but those were EXTREMELY rare cases.
Sorin, thank you for this video, but as well you can look how stable your readings on the meter are. If the CPU is taking a stable current = OK, but, when it jumps up and down = not good ;).
I want to buy a tablet that I can easily open it, that has screws instead of glue, I have ipad pro 12,9" and once the digitizer is cracked I needed to buy a new display with the digitizer. Why we cannot find a tablet similar to a samsung cell phone that can easily remove its back to change the battery or buy a glass digitizer and replace the cracked one once the glass of the display is cracked. Can you suggest me a tablet that is easy to repair and open?
But replacing CPU not too much difficult or needs hard work, i have the same opinion before but after doing it and practice it many times I found it easy now , re balling chips is necessary to everyone working in electronics
The soldering work and CPU usually cost more than the whole board. And if you make a mistake repairing the power circuit the new CPU will blow up, what then?
Good lesson, thank you. What is the resistance of a good GPU compared to a defective GPU?. Does a good GPU usually have more or less resistance than a good CPU?
Sorin get scrcpy .. the u can put it on a screen.. and use a cellphone holder.. U can use the obs studio .. much better Luke ur power supply on screen !!
Replacing whole CPU or GPU or PCH(if separate) is just not cost effective. For some research some time ago I have checked even for cheaper chineese machines from ali and it just wouldn't pay itself off. Supply of newer chips is also very scarce so usually you have to rely on desoldering newer CPU or GPU from scrap and with price of some scrap, non tested boards it's just absurd to even try to do it conting in how much time consuming of a process it is. I bet that people who repair consoles have such machine in shop but consoles are diffrent and in case of those probability of cracked solder balls is way higher than in a laptop(yes there are dead APUs ofc, but most of them come in after well physical damage so). In any case of dead CPU/GPU on laptop board I just deem it a no fix. I know how to do it, but I won't be investing in expensive machine to do repair for which in most cases clients won't just pay the price so in the end it will just collect the dust. Also just in spent time for 1 board I could make a lot of other jobs in same time frame.
Sorin, I've seen similar on graphics cards that are not short, where you have all power rails present and correct, the clock is running and the reset is off, all resistances read OK but the GPU does not start (does not attempt to read BIOS). With a high resolution thermal camera you can see dark/black patches in the GPU die itself where the silicon seems to be 'dead'. You can compare this with a good GPU of the same type by forcing PCI_RST low so neither GPU are starting, if you don't see the same heat signature pattern in both GPU you most likely have a dead one. A hi res thermal camera with macro lens is an extremely useful thing. Have a play around with your camera looking for cold patches as well as hot ones. 😉
Interesting, yes, make sense
When two Legends meet!
Thank you both!
The same thing happens to FPGAs, TV ASICs, DVR and Monitor processors ... As I repair many different boards, I've seen hundreds of them
@@electronicsrepairschool legends reply to other legends so quickly
Thanks for your videos, I love watching how you diagnose faults, all beyond me., I can just about solder wires on my Model Railway. But we all have our different skills I have been building my own computers now for over 15 years starting with a AMD Athlon, up till recently with a Ryzen 5 5600X. Keep up the good work, good luck with your new site too. 74 year old pensioner here, Chris
I've always been waiting for this lesson on how to really diagnose a faulty CPU, and finally here it is, thank you so much Mr.Sorin.
u welcome heheheh
My favorite Ham-Tube channel. Mulțumiri Sorin.
Congrats on the termal camera, so many videos you talk about the need of having one, dreams come true :)
Sorin thank you. This is showing us where to stop. Parcel heating the chip is saying it
Thank you for sharing, very helpful and informative.
The most useful video for me, thank you very very much
Wow. Very interesing to see how they act under the termal camera👍
Thank you for sharing 🤠🤠🤠
You need a phone holder with an arm 👍or attach it to the side of the microscope some how 😀 save your arms and have two hands free to work
perfect tip video Sorin :)
Thanks a lot sir for your goods and clevers informations .we learn so much thangs .again tousand thanks.
Valuable information Sorin.
Thank you
thans..... mr. sorin...
Хорошо видео. спасибо 👍
pity they don't do socketed cpu any more
Thanks for this lesson, more tips please👏👏👏👍👍👍👋👋👋🤗
This is I think only second time whe Sorin repleced a whole motherboard ;) Wow ;)
Faulty CPUs are very rare in my experience, (way more limited than Sorin's of course)
You're gonna have a faulty CPU if your highside FET fails before the lowside, i think, and you have 12V-20V sent to the CPU. Or if you have feedback circuit trouble or somesuch, sometimes a good whack can have unforeseen consequences.
CPUs are highly reliable semiconductors but not very robust!
Yes,it is....I own before MSI K8N Neo ....Bad capacitors blow my CPU :D
CPU just heat and heat like crazy but nothing more
But today motherboards use better capacitors so IDK how is possible kill CPU
Just overvoltage like lunetic :D Otherwise IDK
Hint, most cheap lenovos from 2013 and later. MB lack any protection on ports thus I have seen many 4th gen and higher CPUs with blown up PCH = CPU dead. With my experience I would say 99.9% boards with shorted vrms have dead CPUs, confirmed with tests. Same for desktop GPU's. Blown VRM = don't even bother, chip is long gone. I bet someone reply to this that it is not a rule. Well at least it's just my own experience. Non dead chips after mosfet short? Happened, but those were EXTREMELY rare cases.
Sorin gud day.. i have questions.. you inject volt how many amps and volts? And where did you put the red probe? On the mosfet? Source?
I was asking myself about the same thing.
It is so anointing that now most CPU, and some RAM and SSD are soldered to the mother board, it makes so much useless electronic waste
Sorin, thank you for this video, but as well you can look how stable your readings on the meter are. If the CPU is taking a stable current = OK, but, when it jumps up and down = not good ;).
I want to buy a tablet that I can easily open it, that has screws instead of glue, I have ipad pro 12,9" and once the digitizer is cracked I needed to buy a new display with the digitizer. Why we cannot find a tablet similar to a samsung cell phone that can easily remove its back to change the battery or buy a glass digitizer and replace the cracked one once the glass of the display is cracked. Can you suggest me a tablet that is easy to repair and open?
What supply coils are doing sir sorin
I don't know if I'm miss-remembering, but wasn't Sorin very anti-thermal cam - lol -.
Muito bom !
But replacing CPU not too much difficult or needs hard work, i have the same opinion before but after doing it and practice it many times I found it easy now , re balling chips is necessary to everyone working in electronics
The soldering work and CPU usually cost more than the whole board. And if you make a mistake repairing the power circuit the new CPU will blow up, what then?
شكرا
Please how can I get this thermo camera?
Mulțumim @
I have seen hundreds of blown CPUs and most of them get hot in one spot. I usually just use my finger
Hay sorin do you want some motherboards for parts?? I'll send them to you ..great work
It's been a long time you repair a graphic chip faults, why?
Good lesson, thank you. What is the resistance of a good GPU compared to a defective GPU?. Does a good GPU usually have more or less resistance than a good CPU?
Nowadays GPUs and CPUs resistance goes to 2-5 Ohm and even 0.011 in diode mode test.
I do have a Dell 15 7559 with 4K screen its nice Laptop
Very confusing when you don't have thermal camera
You can use alcohol
Cool...
Sorin get scrcpy .. the u can put it on a screen.. and use a cellphone holder..
U can use the obs studio .. much better Luke ur power supply on screen !!
Looking at that laptop, I can imagine the tobacco smell
😍
I like my desktop..
Stinky smokers laptop xD
The first view 👍
First one to comment lol
More exciting watching Sorin burn his fingers. I miss the old days, LOL ,,,,,, just kidding
Replacing whole CPU or GPU or PCH(if separate) is just not cost effective. For some research some time ago I have checked even for cheaper chineese machines from ali and it just wouldn't pay itself off. Supply of newer chips is also very scarce so usually you have to rely on desoldering newer CPU or GPU from scrap and with price of some scrap, non tested boards it's just absurd to even try to do it conting in how much time consuming of a process it is. I bet that people who repair consoles have such machine in shop but consoles are diffrent and in case of those probability of cracked solder balls is way higher than in a laptop(yes there are dead APUs ofc, but most of them come in after well physical damage so). In any case of dead CPU/GPU on laptop board I just deem it a no fix. I know how to do it, but I won't be investing in expensive machine to do repair for which in most cases clients won't just pay the price so in the end it will just collect the dust. Also just in spent time for 1 board I could make a lot of other jobs in same time frame.