820-2850 crashing randomly during boot up, already changed the 9560

[nate8organic]

Have a 820-2850 fixed for a customer or so i thought by replacing the 9560. sometimes it will boot fully into osx and runs videos etc without any trouble last time i tested it for 5 hours of video playing sent it back and it was crashing on him every 10 min or less. I will get it to load into osx once and then i restart it to test again and it will crash during loading and keeps doing this until i turn it off for a bit and then re try it. everytime i test it i can get it to load into osx atleast once but crashes more than it will load in. I double checked my work on the 9560 and all is good. I checked voltage on 9560 and im getting 1.35v
Any ideas? weird to me it works fully sometimes. and when i try to run asd it crashes every time before it can load.

 

[Gurmon]

Graphics driver crashing, this is usually fixed by c9560.

You did replace with a non poly-tant capacitor right ?

 

[nate8organic]

yep same as always. and never had this issue before. and unlike normal with the c9560 issue, you can run youtube etc. for hours when it does boot into osx and it wont crash.

 

[Gurmon]

Whats voltage at L9560 ?

 

[nate8organic]

1.35-1.37v at the l9560

 

[Gurmon]

i think you should have 1.8V here. When i'm back in the workshop tomorrow i'll take a measurement on a known good board. Also i'll scope the output as i think it hold be a nice flat power line.

 

[nate8organic]

Okay appreciate your help. i did check with a working board and it was also 1.35v, i was thinking the same thing at first. and should have said that on the l9560 i had solid voltage, pin 1 was 1.37 and pin 2 was 1.35.

 

[larossmann]

Do keep in mind that voltage will vary depending on what the GPU is doing at any given time. 1.35v is fine on that rail for this machine.

This could be anything and I would toss it at this point unless you want to delve into potential CPU/GPU/PCH issue on a 7 year old board.

 

[dukefawks]

Bad GPU/VRAM.

 

[nate8organic]

Understood, and i wish i had checked the voltage on the c9560 when it would crash just as "food for thought".

I'm with you on that one!
This board looks like a pos and when i first worked on it the board looked great then it came back in and it looked like liquid damage and the gpu glue looks like shit and the customer took it into another shop in there town multiple times to have them just take a look and they more than likely did something to it.

will def move on, i had it in the bottom of the shelf for a wile here because of this issue and the customer already had a replacement and was just looking to have it as a back up anyway.
Thanks for the help Louis!
Thanks for the drop in duke. judging the gpu looks like it has been heated, its a likely culprit.