820-2850 chime grey screen

[Gmorb]

Board chimes but i get a grey screen when i connect to external i get nothing. What could be the issue?

 

[Hellfiya]

Sounds like a VRAM issue

 

[dukefawks]

Not VRAM!
Got 3V on L9000?

 

[Gmorb]

Damn too late i totally fucked vram up id need a stencil to get them back on properly at this point tried replacing them totally botched it.

 

[Hellfiya]

I'm very sorry, I thought it could be related to vram because scoopof3d on youtube had similar issue on a compareable model and replacing vram fixed it for him, ill try and find the video

edit: here is the video https://www.youtube.com/watch?v=ANwi3UwTTfE&t=248s

again, im very sorry

 

[aprendiz]

Yeah right, residual heat reach GPU and make the LB work again, there was nothing wrong with VRAM....

 

[Gmorb]

Oh well ive been meaning to start reballing chips like smcs anyone know where i can buy a vram stencil also that metal holder louis uses to keep smc in while reballing?

 

[Hellfiya]

This is my IC holder I use, the smallest it fits is an SMC, anything smaller won't hold:
https://www.aliexpress.com/item/80-...32776759559.html?spm=2114.13010708.0.0.8Mazmt

and i'm not sure which RAM style the mac has but it should be similar to one of these:
https://www.aliexpress.com/item/fre...64e3-4372-b788-2780e803a9dd&priceBeautifyAB=0

 

[Gmorb]

Oh nice thanks.