820-3437 missing cpu core

[MDY]

This board is liquide damage arround U7870 and resistors. Pulsing. Only S5 voltage present

I removed R8167 and I have all coils present volatge but no cpu core.
U7870 generate 1.5V stable.
U3210 looks good no corrosion there. Far from corrosion.

R8162 no istalled on this board and 0V on both pins.

 

[smiba]

ALL_SYS_PWRGD & PM_PCH_SYS_PWROK high when in S0 state, if on both pins of R8162 is 0V I assume its low? Check if PP5V_S0, PP3V3_S0 and PP1V5_S0 is there
Verify around Q8150 area. If all these S0 voltages are there check if the resistors are working within specifications (R8151-R8159)

If the system is pulsing in and out of S0-->S5-->S0 check for a short on all S0 lines

 

[MDY]

I think you dont understand what I did.

1. Board pulsing but I removed R8167 and now NOT pulsing anymore.

2. I have all rails 5V, 1.2V and 1.05 present.

3. CPU missing

These rails appear only when I removed R8167. What that means?

 

[smiba]

P1V8S3_PGOOD, P5VS4RS3_PGOOD, P1V05S0_PGOOD and DDRREG_PGOOD high?

Do you have ALL_SYS_PWRGD & PM_PCH_SYS_PWROK high at the moment? As that could explain why the cpu vcore would not activate

I'm a bit confused on why removing R8167 would solve the no S0. As far as I can see R8167 is a pull-up resistor for the ALL_SYS_PWRGD line. I'd recommend getting it back on. You might not be able to see the _PGOOD lines being high or low without it

 

[larossmann]

Is ALL_SYS_PWRGD present with R8167 on the board? Why did you remove this?