820-3476-A Cant turn on,Fan not spinning,Charger indicator Orange


New member
i have a 820-3476-A logic board,condition as title.
PPBUS_G3H at R7005 pin 1 = 1.663v

resistance mode
PPBUS_G3H at R7005 pin 1 to L7310 pin 1 = 45.0ohm slowly increasing
PPBUS_G3H at R7005 pin 1 to GND = 4.3ohm

any idea?


No, if Q7310/20 was shorted the resistance from PPBUS to L7310 would always be lower than PPBUS to GND. Something else is shorted, check resistance from PPBUS to all the coils and see if any are lower than that 4.3 Ohm. If you cannot find that you can inject voltage on PPBUS and see if anything heats up.