820-02773 A2338 M2 5v 0.05a

[fixupp]

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

 

[2informaticos]

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

 

[fixupp]

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

 

[2informaticos]

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?

 

[fixupp]

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

 

[2informaticos]

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.

 

[fixupp]

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