820-3437-B exact voltages

[PPVCC_S0_CPU]

hi, i have a macbook air early 2014 which was water damaged , i fixed it few days ago and it was working fine until yesterday, now sometimes its having 1/4 fan spin and sometimes nothing happens, the charger has orange ligjht. i was checking schematics and have few problems with it;
the schematic shows that PPDCIN_G3H and PPDCIN_G3H_ISOL should have 18.5 volts but i am only getting 15 volts on it. On PPVRTC_G3H i am getting 3.3 volts.
The water damage was around smc reset circuit and rtc circuit.
can any one tell me exact voltages that i should get on these rails under normal circumsatnces?
if i leave charger connected for few minutes, u3900 gets warm
any help will be appreciated.
thanks

 

[dukefawks]

Corrosion somewhere. The usual suspects are U1900, U1950, U6100 area and the "termination resistors" and traces to them. Also crap under SMC is common. It all depends on where the original corrosion was.

15V on DCIN is fine and will not affect anything, schematic is lazy and states voltage for a 60W charger instead of 45W