Enter the world's most annoying 820-2879. Very close to throwing this into a blender.
It works, but Q7085, SI7149DP runs BOILING hot. I replaced it, same nonsense.
I saw C7085 and R7085 are missing. The pads are missing, the component is missing, the traces going to the pads are missing. It's almost as if a comet landed on the board and little street cleaning robots cleaned up all remnants of it. Without looking at another 820-2879, I would have never seen this. There is no discoloration, no rip, no liquid remnants.
I get a 470k resistor and a 0.1 uF capacitor, and cortical coat them to what would be their original locations. Using some fine wire, one end of each goes to the source of Q7085, the other end of each goes to R7086. Since the pad & traces that connect R7086 to pin 4 of Q7085 are gone, I run a wire to make this connection as well.
At this point the board is back to the setup it had before it was beaten to a bloody pulp in its last life. Beautiful! It turns on, and Q7085 runs nice and cool. Alas, it's slow as hell. Really, badly, terribly slow.
I take the wire off of R7086 to go back to where I was. Nothing. Magsafe lights up but it wont turn the thing on. It'll even charge the battery – the magsafe adapter color will be green or orange, depending. However, it won't turn the computer on. Oy. Did I really make this worse by removing it? I try a battery on it, and now it works. It won't function unless the battery is plugged in.
I've solved no charging, I've solved not running off the battery, I've solved the machine not seeing the magsafe, and I've solved runs slow off battery/runs fast on AC adapter. This is just god damn confusing. The board has the ability to turn on and function with a power source. It has the ability to get power from the DC adapter to the battery... but it can't run off the DC adapter. This is driving me nuts. I know I am missing something silly and AC, as I usually am at 3 AM. If I figure something out, I'll post description and pictures.
