Another 802-2915-B

[Anterweb]

Drink spill,
Wasnt to bad inside, Bit of muck around L8920 / Q8950 area so cleaned that up with IPA ,.

Have no power no lights at all on magsafe, and only reading .205v on F6905. So not getting much of any reading on anything else,. its like no power is getting to the board,

Using known good dc in board and Apple 85w magsafe,

Doing a visual inspection I noticed that D6990 was burnt out, I've replaced that now but it's made no difference.
Am i pissing in the wind with this one or is it fixable?

 

[2informaticos]

Possibly input leakage detected by original charger.
Did you test with fake charger, or lab PSU?

Post exact values of R7080/81 and R7085/86 (measured onboard, ohm scale).

 

[Anterweb]

tried fake charger, same deal.

R7080 = 50k
R70801= 35.2k

R7085 = .230mh
R7086 =145k

 

[2informaticos]

Do you mean still no voltage on F6905?
Is the fuse good?

Change Q7080; resistors value look bad.

 

[Anterweb]

Still onl;y .205v ob either side of F6905 and fuse is good, It feels like a short is bringing down the volatge as soon as I connect magsafe,

As the wife is about to drag me out the door to go and watch bloody disney on ice I havent had time to change Q7080 yet ill do that later butjust having a quick probe I noticed that C6990 is shorting to ground on both sides, if that helps?

 

[2informaticos]

Remove C6990 and check for short on board again.
If still short, change U6990.
Don't touch Q7080 yet...

 

[Anterweb]

Removed C6990 and wow! Not sure if it was the corrosion or something had burnt out here but the board was a complete mess underneath layers of the PCB corroded and traces destroyed,

Guy dosent want to pay to have this repaired so ive thrown it onto the donor pile!,. Might have a go at repairing the traces if I get the time,.