820-2879-B not power on

[machelper]

Hello Everybody

Magsafe light is green and when battery charging orange but after hit power button orange turn green two second later turn orange not fan spin or anything.

No liquid damage,no drop

When measure

PPBUS_G3H = 12.5V ( when hit power button its start to down until 2v, magsafe cable unplug&plug its turn 12.5V again)
PP3V3_S5 = 3.3V
PP09_S5= 0.9V

I think sort to ground any of S0 rails but didnt find

Where can i start to check?

 

[dukefawks]

Something is pulling down PPBUS. Hard to tell which rail it is. First check all coils for shorts to GND.
Also power on with KBD disconnected and using the pads on the board.

 

[machelper]

When checked coils PP5V_S3 line is shorted ground. I found damaged C6213 shorted ground after replacement solved problem

Thank you Duke