820-3115 PP5V_S3: 0v (Pulsing) only green light on charger

[No-Clean]

Board came in with a short on PP5V_S3 U7200, replaced it 2 times just in case, short gone and now board makes it to PP5V_S3 with 0V and about 5 seconds later it pulses to 5V, most other rails also pulse, board is pretty clean otherwise.

SMC, U7400, U6100 (With Clean BIOS) replaced but same thing.

R7402 and R7403 good and surrounding components of U7400 look clean.

SMC Bypass same thing.

ALL_SYS_PWRGD 0V not pulsing

AVREF_SMC 3.3V

PPBUS_G3H: 12.53v
PP3V42_G3H: 3.4v
PP5V_S5: 4.95v
PP5V_SUS: 4.95v
PP5V_S3: 0v
PP3V3_S5: 3.3v
PP3V3_SUS: 3.3v
PP3V3_S4: 0v
PP1V8_S0: 0v

 

[2informaticos]

Any big coil pulsing voltage?

 

[No-Clean]

All pulse but this dont: L7560, L7550, L7510, L7520 and L9701

 

[2informaticos]

Remove Q7950 and check again for pulse at ALL_SYS_PWRGD.

 

[No-Clean]

No pulse after removing Q7950

 

[2informaticos]

"most other rails also pulse"
Which ones you've checked?

 

[No-Clean]

L7260 PP5V_S3
L7330 PP1V5_S3
L7630 CPUVCCIOS0_LL
L7100 PPVCCSA_S0_REG_L
All the above pulse

 

[2informaticos]

Any pulse at 3V3_S0_FET?

 

[No-Clean]

3V3_S0 does pulse.

 

[2informaticos]

Remove R7963-6, one by one.
Check when appears the pulse on ALL_SYS_PWRGD.
Maintain R7967 in place, of course.

 

[No-Clean]

My bad ALL_SYS_PWRGD does pulse, I was measuring ALL_SYS_PWRGD_R

 

[2informaticos]

Monitor U7400's voltages: 19/29, 46, 47, 1, 49.
Can you detect any pulse on them?

Did you check all SPI Bus Series Termination resistors and their traces?

 

[No-Clean]

U7400's voltages:
19/29 Pulses
46 Pulses
47 Pulses
1 Steady 12.3V
49 Does not exist
48 Steady 12.3V but reboots every few seconds

 

[No-Clean]

U7400 does not exists in that IC

 

[No-Clean]

Yes checked all SPI resistors and traces, all look clean, overall board looks clean

 

[2informaticos]

You've said 12.3V on PPBUS_G3H in first post; later 12.3V.
What is actual voltage?
12.3V may denote a SMC issue.

However you shoulkd get at least a pulse on CPU core; as same time with ALL_SYS_PWRGD.
PCH, or CPU may have problerms.

There was possibly an overvoltage on 5V_S3 power rail.
Check any other power rail derived from it.

 

[No-Clean]

PPBUS_G3H is 12.6V
But pin 1 of U7400 (CPUIMVP_TONB) is 12.3V R7403 is fine.
ALL_SYS_PWRGD does pulse, but VCORE does not.
Checked all other rails on page 8 all okay.
Thanks!