820-00165 - Board does not turn on

[Palhano]

Logic board in good condition. It has by SMC bypass, does not turn on.

RTC_RESET_L - 3.26V
PCH_INTRUDER_L - 3v (it was 1.5v, I replaced it with a 100k resistor)
PCH_INTVRMEN - 2.5v
PCH_DSWVRMEN_L - 2.4v
PCH_SRTCRST_L - 3.26V

PPBUS_G3H - 8.6v
PP3V42_G3H - 3.4v
PPVRTC_G3H - 3,3V
PP5V_S5 - 5v
PP3V3_S5 - 3.3V
PP3V3_SUS - 3.3V
SMC_ONOFF_L - 3,37v

SMC_ADAPTER_EN - 3.3V
SMC_PM_G2_EN - 3.4V
PM_BATLOW_L - 3.3V
PM_PWRBTN_L - 3.4V
PM_RSMRST_L - 3V
*PLT_RESET_L - 0v
*ALL_SYS_PWRGD - 0v

PCH problem?

 

[2informaticos]

Trigger SMC_ONOFF_L and check for drop pulse at PM_PWRBTN_L (at same time).

 

[Palhano]

Yes, it has a drop. goes to 1.5v when I trigger SMC_ONOFF_L

 

[2informaticos]

It should drop to 0V; check maintaining button pressed 1-2s.
Check if PM_SLP_S4_L pulse at same time.

 

[Palhano]

PM_PWRBTN_L drops to 0v by pressing SMC_ONOFF_L.
PM_SLP_S4_L only pulses when I press SMC_ONOFF_L. Values change with each test, had 0.5, 0.8, 1.5v

 

[2informaticos]

Check for pulse at PM_SLP_S3L.
Next, check on all big same coil; when triggering SMC_ONOFF_L.
Inspect U1950 for corrosion.
Check for pulse at its pins 7 & 3.