820-3435 DCIN Leakage

grmacs

Member
This board had liquid damage to the entire area DCIN/3v42 of this board: from C7098,L7095 area through D7012, ALL of those components have been replaced. This board boots from PS input but not from original 85W charger.

On original charger:
PPDCIN_G3H is around 1.5V most of the time
Diode mode there is 0.5
I've replace D7012 twice, ISL twice, Q7180 3x (last time I did Q7180 at same time as ISL just in case), Replaced Q7010 twice
Resistors i've checked that measure good: R7005/6, R7010/1/2, R7180/1/5/6, R7105, R7010/1
REsistance between pins 17/18 of ISL is 2.1 ohms, 27/28 pins 20 ohms.

Once briefly after replacing ISL the board started but I believe this was shortly after having on power supply so not sure if that was related.

Any thoughts? I feel like I've replaced everything I could think of for typical leakage cause at least once.
 

grmacs

Member
Those resistors are good as mentioned and yes, tried different DCIN boards.
Somehow I started getting intermittent board start up on original magsafe charger.
I changed the DCIN Port and Q7080 and Q7010. PPDCIN is consistently 16.8V now but PPBUS G3H is consistently low 1.1V

ISL:
1- 0V
2 - 16.5V
3 - 4V
6- 0V
9- 0V
12- 3.4V
13- 3.4V
14- 3.4V
17- 1.1V
27- 1.1V

Same REsistance between pins 17/18 of ISL is 2.1 ohms, 27/28 pins 20 ohms. I changed ISL again and same results.

diode at PPBUS G3H is .138
 

grmacs

Member
Well there previously must have been multiple issues remaining but I ended up replacing Q7180 for the 4th time and all is good. Unfortunately I don't know what the other problem that got solved ultimately got the board working. Must've been something that was blowing the Q7180's that I eventually replaced.

This one was a nightmare so not worth fixing but I can't NOT fix a charging issue haha!
 

grmacs

Member
Ahhhhhh... maybe that's what it was? I harvested off boards with non-charging issues but I will order new. Not worth beating my head against a bench for 3 hours over a $50 board haaha
 
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