820-2850 No power. Green light only

[rob777]

hey guys. Been a while since posting. Must of learnt something!
Am now stuck on a old 820-2580 board. Seconds away from giving up and this post is my last resort.

PPBUS_G3H is not holding and is always changing values. From around 8v to 12.6v.
F7040 is fine and I even changed U7000 off a working board. Same result.
R7020 and R7050 are those sense resistors. I don't quite understand how they work although the readings seem fine. Can't find any shorts.
Possible for some nudges in the right direction??
Thaks again.

 

[rob777]

can close this. I fkd the board good and proper. Made a fire

 

[dukefawks]

So this is obviously a liquid damaged board you got. In most cases no battery recognized is a dead SMC and U7000. Did you test with a good battery? Yours could have died in the fire with the other board. Also the battery indicator can cause issues, disconnect it to be sure.

 

[rob777]

Thanks Duke, I think your right, it does seem so.. I'm going with dead, I tested with two working original batteries. Only had a fan, dc port and battery connected too.
Probably best off doing an eBay return at this point. It cost me $675AU!

 

[rob777]

actually probably try changing u7000 first I reckon

 

[dukefawks]

675? Fuck that shit. Return that garbage.

 

[rob777]

Changed it, no difference. Got ripped. Sending it back.

 

[rob777]

One last go...
r5281 is 3.4v r5280 is .5v
i don't have a working oscilloscope to know if pins 2 of r5280 and r5281 are doing what they are supposed to do right now either.

Changed u7000 r5281 and r5280. Something is fucking up the data lines.

 

[dukefawks]

SMC is dead...