820-3476, Liquid Damage, No 3V and 5V rails

[nbosna]

Liquid damaged board for MBP 13" A1502, plugged into charger, I get a green, then orange light, no fan spin. I measured the following:

PPBUS_G3H: 12.58
PP3V42_G3H: 3.42
PP5v_S5: 0
PP5v_S0: 0
PP3V3_S3: 0
PP3V3_S0: 0

Corrosion/build-up was around U7501 and Q7155. Cleaned up in ultrasonic, but still get the same measurements above. Can anyone help troubleshoot the U7501 circuit - I'm convinced the issue is here somewhere.

 

[aprendiz]

Voltage on Pin 23 and pin 12 from U7501...... This seems to be a bad U7501 but lets confirm first.....

 

[nbosna]

Thank you for the response. I get 3.41 volts on pin 12 (SMC_PM_G2_EN), and between 0.6 and 0.8 volts on pin 23 (VIN).

 

[dukefawks]

VIN is not correct, probably corroded trace.