820-3662 no green light

Board is clean, no signs of liquid damage, PP3V42 is present
PPBUS_G3H was at 4V, no green light on charger
R7121, R7122 both blown
I've replaced both resistors and U7100
Now PPBUS_G3H is 12.6V as normal but I still don't have a light on the charger and board won't start. Board seems to start in SMC bypass mode
SYS_ONEWIRE is 0.7v. I've tried replacing U7000 but no change.
Also tried reballing SMC, still no change.

Anything else I should try before I replace the SMC?
Thanks
 
Hi, sorry just got back around to this board now. I've got the following at U7000

1SMC_BC_ACOK_VCC3.416v
2GND0v
3NC0v
4SYS_ONEWIRE0.773V
5ADAPTER_SENSE0.716V
r7029 1.98KOHM

I don't have another DC-board on hand for this model but I think the one I have is good. All the inductors/resistors seem to measure ok/low resistance and the little chip marked P7 doesn't seem blown (I've seen them burn up before)
 

2informaticos

Administrator
Staff member
If you are sure about DCIN board, change SMC.

I first recommend to try removing TVS diode from DCIN board.
You cannot correctly diagnose a diode with the eye!
 
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