820-2936 No power, weird issue

tlough75

Member
U6990:

1: 1.2V
2: 3.8V
3: 16.65V
4: 18.3V
5: 0V
6: 0V
7: 1. 8.3V
8: 3.8V
9: 0v
10: 0v


L6995: (Diode)

Pin 1: .353
Pin 2: .352
 

tlough75

Member
So I found something out, When I put my red multimeter probe on Pin 9 of U6990 and hook up charger, I get a pulse of PP3V42_G3H rail. SO that tells me the chip is trying to put 3.42V out but something is stopping it.
 

tlough75

Member
I did. It is fixed. There was a broken via right above Q7810 (3V3S5_VFB_R7270). Ran a wire from R7270 into a via to L7220 and now have a working machine. Holy smokes this was a tough board. But it is back in the chassis and running Sierra like a champ.
 
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