820-3115 intermittent green light/power

[daniel_andrei1996]

So I have an 820-3115 board. No obvious liquid spill but some green probe points from humidity
Will always power from battery, however if using charger only behaviour is random
Sometimes no green light, sometimes green light but no boot, sometimes it'll boot like normal
Once on it will stay on.
My PP3V42 is there, but I could swear it sometimes takes a few seconds to come up
PPBUS_G3H is sometimes 12.2V, sometimes 12.6V.

This is very weird behaviour and I don't see anything obvious around SMC or U6900. Any ideas?

 

[2informaticos]

If you always get PPBUS_G3H on charger only, then input leakage is discarded; even when the voltage value is just 12.2V.

Check exact resistance between pins 17/18 amd 27/28 of U7000.
Resolder entire area and inspect for corrosion.

Post PM_BATLOW_ , SMC_RESET_L, SMC_PM_G2_EN, 3V3_S5 when doesn't want to turn on.

 

[daniel_andrei1996]

If you always get PPBUS_G3H on charger only

sorry i should've said, I'm using 85W magsafe cable on bench psu. if it makes a difference

 

[2informaticos]

Ooops, then check if you get PPBUS_G3H with original charger.
ALWAYS use original charger.
Lab PSU is good to discard leakage, but not recommended as normal power.
You could have a leakage issue, hidden by lab PSU...