how to diagnose if it is bad GPU or bad GPU RAM

[ktmmotocross]

Hello.
Have macbook with bad GPU. after replace GPU with new IC, the book come back in life but have bad video image. There is GPU RAM on the other side oof bosrd and it be heated many times.

Do u think that bad image is due to bad new GPU IC or have cracked ball under GPU RAM ?

[mcplslg123]

Re: how to diagnose if it is bad GPU or bad GPU RAM

Both are probable so you can never be sure unless and otherwise you remove those ram chipsets.

[mosfetratus]

Re: how to diagnose if it is bad GPU or bad GPU RAM

Bad video ram would crash the system.

Could be two things, bad chip or bad soldering. Bad soldering is less likely to be. Higher chance to have a bad chip, what date code is the chip?

[piernov]

Re: how to diagnose if it is bad GPU or bad GPU RAM

Very hard to find good GPU. 216-0810001 and 216-0810005 are not available, 216-0809000 maybe but almost everything is reballed dead GPU.
So… first thing I suspect the GPU.

Did you remove the edge bonding of the VRAM though?

[ktmmotocross]

Re: how to diagnose if it is bad GPU or bad GPU RAM

yes i removed bondig but it was two times heated before with bonding

gpu was 216-0810005. chip was "new" for a fair price of 16eur from aliexpress. got another chip for another laptop from same supplier and it was good

[piernov]

Re: how to diagnose if it is bad GPU or bad GPU RAM

That's a dead chip for sure. Even if it did work, it wouldn't work for long.