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[SOLVED]820-2936 Quarter Fan Spin

S

SMMRepair

Member
820-2936 had liquid all centered around Q7030, Q7035, C7035, U5420 and U5421. No liquid to SMC area or clock area. No liquid to U7000 directly. Fan spins for half a second, turns off, ad infinitum.

- ppbus_g3h is 14.24v
- pp3v42_g3h is 3.45v
- resistance between pins 17/18 is 4.13Mohm (which is of course way too high)
- resistance between pins 27/28 is 19.5ohm
- pin 3 of U7000 is 3.96v
- board runs with battery connected (and with battery/charger connected)

R7051/52 measure properly, but I replaced them to be safe. No change. R7050 measures properly. Replaced U7000 and Q7030/Q7035, no change. What could be causing the resistance of pins 17/18 to be so high? Could it be Q7055? Would the board still power on and run fine with battery if Q7055 were at fault?

Thanks in advance!
 
S

SMMRepair

Member
Thanks Aprendiz; I can't believe I didn't check that. I checked continuity from ISL through the resistors, but didn't from 7051/52 to 7050. Will run those wires and check back--thanks.
 
S

SMMRepair

Member
You got it, thanks Aprendiz. I didn't think the traces would be burned internally, so didn't really think to check continuity that far down. I guess it makes sense since U5420/21 were partially burned up. Thanks, Aprendiz! You guys can close this one up.
 
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