820-3536-05 No Green Light. Works on Battery.

[drewrox2009]

computer had liquid damage
works completely fine on battery but will not power on with charger, will not charge battery
I don't see any obvious corrosion points and have finished an ultrasonic on the machine.
I am at a loss of what to check. I know the PP18V5_DCIN is very low but cant find anything pulling it down.


no green/orange light

Here are some measurements i took.

pin 1 and pin 2 of j7000 pulse to 24v then drop back down to 2-3 v and orange light when testing voltage
68k resistance from pin 1 j7000

r7012 68k
r7010 101k
r7011 10k

r7020 46.9

l7095 0


r8141 95k

pp3v42 pulsing from 100mv to 3.42v only when testing
pp3v3_s5 missing
PPBUS_G3H 290mv
smc_pm_g2_en missing


r7116 3.02k
r7115 99.9k
r7112 1.01k
r7142 1.01k

r7110 59.3k
r7111 21.07k
r7105 20
r7185 467k
r7121 10
r7122 10.2
r7180 1.29k
r7181 61.4k
r7125 0
r7120 .01

Glad to be here i have already fixed a board going through previous topics.
Thank you in advance.

 

[larossmann]

I'd ask for resistance to ground on pins 1/2 of J7000, but my bet is Q7180 is bad. Do you have a donor board to swap from?

 

[aprendiz]

Voltage on gate from Q7010??

 

[drewrox2009]

I do not have a donor board with the same q7180, but i can order the part.

Resistance from pin 1 to ground is 68k

2.63v on gate of q7010

 

[drewrox2009]

I just pulled q7180 and inspected, there was a bit of corrosion between one of the pads on the chip and the board, i cleaned and reseated, and now it is working, is this possibly a case of heating a transistor making it temporarily work or is it possible that the corrosion was the culprit?

 

[drewrox2009]

Turns out that was the case, as soon as the board cooled down from heating in that area, the board stopped powering.
i have a q7180 from a 820-2915 turns out it was the same component. Swapped, powers on battery is charging. This case is solved.

Thank you guys so much! i had sat this motherboard aside a couple of months ago.