820-00165 Missing S4_PWR_EN, PM_SLP_S4_L Missing

[No-Clean]

Board had a little bit of corrosion around C2952 and PP3V3_S4 was shorted (C2952 and U8000) both replaced but I am missing PM_SLP_S4_L and S4_PWR_EN is only 0.310V

PM_SLP_S4_L Diode 0.474
SMC_S5_PWRGD_VIN Present
PPVRTC_G3H Present
U1950 Pin 8 has 3.4V

 

[2informaticos]

"Board..."
???

 

[No-Clean]

Sorry, title corrected for board ID

 

[2informaticos]

Trigger SMC_ONOFF_L and check for pulse at PM_SLP_S4_L, at same time.

Did you test SMC bypass?

 

[No-Clean]

I do get a pulse on PM_SLP_S4_L when I trigger SMC_ONOFF_L, bypass same thing.

One thing I noticed is that PM_SLP_S4_L and S4_PWR_EN pulses once at the correct voltage right after I connect charger.

 

[2informaticos]

That's normal; all iCore Macs have auto power on, if battery is not connected.

Check PM_SLP_S3_L too.
Next, check for pulse at all S3 and S0 power rails.
Don't forget ALL_SYS_PWRGD too.

 

[No-Clean]

PM_SLP_S3_L is 0V but when I trigger SMC_ONOFF_L it pulses to 3.3V
PP3V3_S3, PP3V3_S0, PP1V8_S3, PP1V2_S3 all 0V but do pulse when I trigger SMC_ONOFF_L

 

[2informaticos]

What about ALL_SYS_PWRGD and PCH/CPU coils?

 

[No-Clean]

Cleaned it in UC after the repairs I did and now board works, thanks a lot!