820-00138 stuck on Apple logo

Narek

Member
Hi! I'm working on 820-00138 which is not booting to OS. Actually for most of the time it's stuck on Apple logo, there is even no progress bar. Sometimes after many SMC resets it will load OS to user screen or opens boot drive selection, but for most of the time there is only Apple logo. Board has no signs of liquid or other damages. I suspect bad BIOS, could you please share clean one for this board? Or at least clean ME in mine (link below)?


 

Narek

Member
It doesn't load system at all, even in safe mode.

EDIT.

I have tried several new BIOS files and on some of them computer doesn't even start, on one which seems to be legit clean ME BIOS computer behaves a bit different - when SSD is plugged in I have nothing on the screen, just backlight and computer is very slow. If I remove SSD I'm able to get to boot menu, but if I will try to run test OS it will get stuck on Apple logo or black screen.
 
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Narek

Member
Correct, I can't load macOS from USB drive. Also windows installer gets stuck while loading, It can't get to istallation screen, just hangs on windows logo.
 

Narek

Member
With all devices but LCD disconnected It's still not able to boot into OS on external drive, nor to Windows intstaller. The same in another shell. Bad PCH?
 
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