820-3536 - Liquid damage, no power

[gcain]

Originally had a dead short in U5560, swapped it out.

Then Q7630 was getting really hot, so I swapped it out.

Then C7600 was blistering hot, so I swapped it out.

Now it gets sort of warm around U7600 but I can't tell where the heat is coming from.


PPBus_G3H = 1v


There is a short, I just can't work out where it is. Even with alcohol sprayed down, nothing shows up.

Maybe the issue is on the other side of the board.

 

[Repairable]

Maybe the issue is on the other side of the board.

yes most likely because most water comes in by the fan or keyboard.....

check this first

green light on charger?
onewire?
CHGR_ACIN ?
ohm on pin 27/28 u7100

 

[gcain]

Maybe the issue is on the other side of the board.

yes most likely because most water comes in by the fan or keyboard.....

check this first

green light on charger?
onewire?
CHGR_ACIN ?
ohm on pin 27/28 u7100

Greenlight okay,

CHGR_ACIN on R7110::2 = 0.8v actually.
It comes up as 3.4 else where (C7111 & R7111 eg.).

U7100::27/28 = 20.2ohms

 

[Repairable]

CHGR_ACIN needs to be around 4 volts if i am correct.

check R7110 and R7111

and stil check other side of the board

 

[gcain]

I think it's U5560 that's getting hot.

It has already been replaced.

R7110 = 3.98v on both pins.

R7111::1 = 3.98 & R7111::2 = 0.08v, == 20kohms.

So something is pulling it low.

 

[gcain]

Diode mode on R7111::2 = 0v.

 

[dukefawks]

Yeah no, high side FETs were shorted and I bet 1V05 got PPBUS straight to it. Pretty sure this is toast.

 

[gcain]

Spewin'.

Thanks Duke.