820-3476 Voltages come up for a couple seconds and then turn off

[bjf]

After about two seconds I lose power. Very slight liquid-damage.
3V3_SUS goes to 0V.
PPVRTC_G3H stays stable at 3.3V.
PM_BATLOW_L is at 3.3V.
SMC_ADAPTER_EN is at 3.3V.
5V_S5 is at 5V
5V_S4 goes to 0V
PM_SLP_SUS_L goes to 0V
S5_PWRGD is at 3.3V
PM_DSW_PWRGD is at 3.4V
PCH_DSWVRMEN is at 3.2V
ALL_SYS_PWRGD goes to 0V.

No pulsing on any of these lines.

Not sure where to look next.

 

[JohnB8812]

Where was the liquid damage?

 

[2informaticos]

Try to start in SMC bypass mode.
Exact value for PPBUS_G3H?
Trigger SMC_ONOFF_L signal and see how PM_PWRBTN_L reacts.

 

[bjf]

No change with SMC bypass - comes up once, just with full fan.

PPBUS_G3H is normal at 12.58V

PM_PWRBTN_L drops down to 0V when triggering SMC_ONOFF_L

 

[2informaticos]

Check if all PM_SLP_Sx_L signals pulse.
Also check for pulse at pins 1, 7 & 3 of U1950.
All big coils pulsing too?