nameless
Member
Hey everyone,
Working on a MacBook Pro 16" 2019 (820-01700) with coffee damage. Looking for input before I go further.
Symptom: No power, no fan, no chime — completely dead. Charger cycles 5V ↔ 20V with current fluctuating 0.01A to 1.2A.
Liquid damage locations:
What I did:
Questions:
Thanks for any input.
Working on a MacBook Pro 16" 2019 (820-01700) with coffee damage. Looking for input before I go further.
Symptom: No power, no fan, no chime — completely dead. Charger cycles 5V ↔ 20V with current fluctuating 0.01A to 1.2A.
Liquid damage locations:
- U3100 (CD3217) — visible corrosion
- J8400 area (keyboard backlight)
- C4956 area (PP3V3_G3H_T)
- T2 area looks clean
| Rail | Reading |
|---|---|
| PPBUS_G3H | 12.6V (battery) |
| PP5V_S5 | 5V ✓ |
| PP3V3_G3H | 3.3V ✓ |
| PP1V8_G3S | 1.8V ✓ |
| PP1V05_S0 | 0V |
| PP0V82_S0 | 0V |
| PMU_ONOFF_L | 3.3V, goes LOW on button press ✓ |
| PMU_RSLOC_RST_L | 3.3V ✓ |
| I2C_UPC_X_SDA2 | 1.8V ✓ |
What I did:
- Replaced U3100 (CD3217)
- Result: 3 ports now negotiate to 20V, 1 port still stuck at 5V
Questions:
- Should I replace U3200 before diagnosing T2? Seems logical but wanted confirmation.
- Anything else I should check before assuming T2 damage?
- On this board, what's the best way to confirm T2 is actually dead vs firmware issue?
Thanks for any input.
