I had the same issue and actually found that dmit2k's comment got me up and running again. I first took it to the Apple store and they said it was a goner, needed new logic board and wouldn't be covered by a flat rate repair because of the liquid damage. I went home, found dmit2k's comment, disconnected the LED indicator light module, and the machine has worked fine since though it doesn't always go to sleep if I close it.