820-00840 u7370 hs

[raainxx]

Hi,
this board has U7370 burn, PPBus is short.
I remove it and change it with a donor board, PPBUS come back at 11,98V, PP5V_S0=5V
the fan spin 5 second and nothing more.
I have all_SYS_PWRGD at 0V
PPVCCSA_S0G_R = 1,05 instead of 1,5V is it normal?

 

[2informaticos]

1.05V is correct there.
Overvoltage because of burnt U7370 could already killed CPU.

Maybe waste of time, but you can still investigate why ALL_SYS_PWRGD stays low.
U7800 checks various power good signals before releasing ALL_SYS_PWRGD.
Check if all are correct...