820-3330 PPBUS_G3H 1.7v

[MUUK]

Not liquid damaged (or very well cleaned)
Green light and pp3v42 present.
PPBUS_G3H - 1.7v with 0v volts to ground in diode mode

Removed fuses F7040 / 7041 short is on PIN2
Pin 1 with fuses removed is 12.56v so generation is working




Injected some voltage into pin2 got to 4.5v @ 8amp
CPU got warm,
C7242 was hot
PPVIN_S5_HS_OTHER_ISNS diode mode to ground was 0v (measured 1.4v on another board)
Removed the following components checking each time to see if short was gone

C7242
C7282
C7280
C7270
C7241
C7281
C7240
Q7220
Q7260
C7200
C7283

Still shorted to ground in diode mode. Cannot find anything else getting hot. I'm always cautious injecting voltage, should i raise it higher ?
I suspect CPU shorted to ground pulling these low or a short in the board but would appreciate and insight! Thanks,

 

[dukefawks]

Yup CPU is probably already dead by now. Shorted Q7510/30/50. Replace the shorted FET and the driver it is connected to, but CPU is most likely dead.

 

[MUUK]

Thank you Duke. Q7550 pin 4 was part of the problem (burnt underneath) - short follows back through Q7551 pins 1/2 - removed Q7551. Short still present on pads 7/8 - assuming CPU is very dead