Not booting, component level troubleshooting...

I’m working on a A1278 2012 13” MacBook Pro with a 820-3115-B logic board that has suffered liquid damage. No, I am not a wannabe repair technician trying to charge someone, this is my computer.

Green light with battery connected turns orange then goes out after 20 seconds. Green light with no battery goes out after about 30 seconds. Disconnect Magsafe and reconnect, light on.

If Magsafe is left connected and AC disconnected and reconnected, no green light.

No boot and no fan spinning.

Tested PPBUS_G3H rail and all sub paths have 12.59 v on the supply side. Started testing all data points listed on page 7 and these were the anomalies I’ve gathered so far.

PP5V_S5_LDO - 4.99 v

PP5V_SUS_FET - .303 v

PP5V_SUS_PCH - .303 v (measured at D2400 pin 3 & 4)

PP5V_S3_REG - 0 v

PP5V_S3_DDRREG – 0 v (measured at C7300 pin 1)

PPVIN_SW_T29BST - .22 v (decreasing value) (measured at Q3880 pins 2 & 3) I think this is Thunder Bolt which is not interesting to me, but I thought I would give all known measurements.

I'm thinking there is possibly a short in one of the P5V circuits causing the voltage drop and causing the green light to go out.

Looking for next steps…