820-2936 ppvccsa_s0_cpu

G.Beard

New member
Hi.

Measured diode drop 0 on L7100
Removed R7140 and got 0 drop on pin 2 pad for where R7140 used to be. No short on any of the 3 remaining pads.
Thought it may be bad bypass caps so injected voltage On pad 1 of C1768 @ 1v 4A and all that got hot was the CPU, nothing around it got hot on either side of the board.

Not sure where to go from here?
 

dukefawks

Administrator
Uhm, is there a short on PPBUS? 0.4 on L7100 is way too low, possibly shorted high side FET killing CPU and shorting out PPBUS?
 

G.Beard

New member
Uhm, is there a short on PPBUS? 0.4 on L7100 is way too low, possibly shorted high side FET killing CPU and shorting out PPBUS?
Yes short on PPBUS_G3H. Removed F7040 got 12v5 no load from L7030. Chucked in some voltage on pin 2 pad of F7040. CPU getting hot.
I'll check Q7100 now

... Q7100 has a fat hole in it
 

G.Beard

New member
PPBUS_G3H = 12.6V
L7030 to ground 1.1ohm

I'll post with something more useful
 
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