820-00165 in S0 State - no power

[Dusten04]

Hey everyone, looking for some help here;

820-00165, I’m in an S0 state, but no power.

I seem to have all the S0 power rails besides vcore.

I do not have ALL_SYS_PWRGD. I have checked the pins on Q8150 and are the following:
VMON_Q4_BASE = 0v759
S0PGD_BJT_GND_R = 0v087
ALL_SYS_PWRGD = 0v668
VMON_Q2_BASE = 0v675
S0PGD_C = 0v128
VMON_Q3_BASE = 0v675
I’ve replaced Q8150 and same result

I've also replaced from advice of others:
Y1915
U1950

 

[2informaticos]

Do not change anything without a good reason.

Q8150 is a redundant protection and can be simplt left out, for test; not really need to put it back.
Its inputs look good, but easy to test in case of doubt.

You didn't specify if all S3/0 voltages are present.
Of course, VCORE cannot appear if ALL_STS_PWRGD is not present.
Remove (one by one) R8164/65/66/68 and test each time; keep R8167 in place!
Start with R8166; many times fails (w/o reason) power good from 1V8...

 

[Dusten04]

Wow thank you man. After removing the last resistor (R8168) I got fan spin! Now to put new resistors on

 

[Dusten04]

Okay, after installing another R8168, no fan spin again

 

[2informaticos]

How did you think R8168 could be bad???

If DDREG volatge is OK, let R8168 out and check if board works.

 

[Dusten04]

How could I think R8168 was bad? On a wing and a prayer I guess. I saw fan spin and got excited, thinking I found my issue.
I checked all the voltages going to the line, per your suggestion, with a closer eye this time, and noticed that PP1v2_S3 was 1v08 instead of the expected 1v2 (Initially thinking this was in the margin of error). So After checking the resistor R7450 to make sure it was in spec, I decided to change Q7430. Once I did that, I got the 1v2 I was expecting, and board fixed. Thanks again for your help