PP3V8_AWAKE_TCON = 0.570 diode / 2 Megaohms resistance
Between PP3V8_AWAKE_TCON_ISNS and PP3V8_AWAKE_TCON_ISNS_R I get 0 ohms

Yes, it works with external monitor with no problems. I can log in to system, etc.

Got a MacBook Pro M1 Pro 16'' to rescue immediately after liquid accident - I got it in less than 30 minutes after the spill.
It got spilled from behind when the laptop was closed. It mostly affected the rear of the mainboard and the bottom of the LCD.

I quickly took it apart and washed the liquid residue off the mainboard.
The area around the UP800 had some light corrosion, but it just washed away with some IPA. Other areas looked undamaged.

The mainboard got a thorough cleaning, as did the top case and LCD connectors / cables.

Now the laptop...

So in essence, what I found and corrected:
- CR604 was badly corroded and removed
- RD531 was O/L also corroded and replaced
- CD3217 area wasn't affected at all, every LDO voltage measure spot on

Voltages:
-All voltages expect the following are present:
-PPBUS_G3H is 12.3V (should be 12.6V or more)
-PP5V_S2 is missing and not shorted
-PP5VS2_EN is also missing (generated by U8100)
-On the U8100 all LDO voltages are present, except for MPMU_VREF_ADC
-U7700 has all the output voltages present


So from what I...

Found a corroded resistor: RD531, replaced it, no change. Also that cap that was shorting PPBUS_G3H was CR604 which I removed, but it should work without it.

Next, I was checking all the LDOs and discovered that I am missing one voltage: MPMU_VREF_ADC, which is at 0V. All other voltages (except for PP5V_S2) are all present.
MPMU_VREF_ADC is not shorted and it reads 0.590 in diode mode.

So where to look next? Nothing else is looking crusty or corroded....

Resistance is over 2M ohms. Diode drop is 0.315.
PP5VS2_EN is also missing...

Board had some light liquid damage, nothing serious, just one bad looking cap that I removed (from PPBUS_G3H to ground), near speaker amps.
There was no corrosion as such, just few tiny spots, really minor.

The board is stuck at 5V, it draws 0.1A all the time. Only at poweron the amperage surges up to about 0.15-0.18A, then it settles at 0.1A.
I put it in DFU and it didn't do anything, wasn't detected on other machine.

Voltages all seem OK near the CD3217 chips, all LDOs are present, also no liquid damage was nowhere around those.
But measuring other...