820-02773 A2338 M2 5v 0.05a

Water damage board around U5700, Q5800 5820 5840 and U8100.
Replaced U5700 then have 3.8v on PP3v8AON.

PP3V8_AON_MPMU_ISNS_VIN is 3.8V
P5vs2 and others S2 rails: 0V.

U8100 is fine as I tried to install this IC to other M2 board then it is working. U8100 seems to not turn on. I have checked all the rails arround and confirm no short.

what should I check next? and what is the condition for the U8100 to turn on. Also, what power sequence for this M2 macbook? thanks

Check all MPMU LDOs; voltage and diode mode.
Don't bother with "NC" ones...

found the issue with PP3V3_AON.
PP3V3_AON jumping from 0.3 to 0.9 but no short. No short and diot value corrects

MPMU_BSTLQ_LX 3.8
PP5V_MPMU_BSTLQ_XW 5v
PP1V2_AON_MPMU 1v2
PP1v8AON: 1v8

There are more LDOs available.

You may have just a small capacitor, or resistor corroded somewhere.
But also is possible to have more damage; maybe corrosion under some BGAs.

Is the machine recognized in DFU mode?

No it is not recognized in DFU.
Does it mean I have a short somewhere?
Which page where I can find all the LDOs?

You have all MPMU LDOs on page 37.
Check the input voltages on left side and LDOs on right side.

Do the same for SPMU, page 32.

U8100
Imput: NO SHORT
PP3V8_AON_MPMU_ISNS_VIN 3v8
PPVDD_LDO20_14_8_3: 0v no short
PPVDD_S2SW_VDD2H: 0v no short

Output: NO SHORT
PP1V8_AON: 0 no short
PP3V3_S2_LDO: 0v
PP1V2_AWAKE_PLL: 0v
PP1V8_AON_MPMU: 1v8
PP1V2_AON_MPMU: 1v2
PP3V3_AON: 0.3-0.5v
PP0V855_S2SW_CIO: 0v
PP3V3_S2SW_SNS: 0v
PP1V2_S2_CIO: 0v
PP1V5_LDOINT_MPMU: 1.5V

U7700:
Imput: NO SHORT
PP3V8_AON_SPMU_ISNS_VIN: 3v8
PP1V25_S2: 0v
PP0V88_S1 0v
PP1V8_S2: 0v

Output: NO SHORT
PP0V72_S2_VDD_LOW
PP1V8_AON_SPMU: 1v8
PP1V2_AON_SPMU: 1v2
PP0V8_S1_VDD_FIXED: 0v
PP1V5_LDOINT_SPMU: 1v5
PP1V8_AWAKE_SPMU_GPIO: 0v
PP1V25_AWAKE_NAND_VCCQ: 0v
PP0V88_AWAKE_NAND_VDD: 0v