Just had a retina going fine. Determined it needed a new battery. Put one in, and the mag safe light goes off. I suspect it's blown the mag safe? I changed MagSafes, ran the board sans battery, works fine. Plugged in battery, plugged in MagSafe, light was green for a moment, then dead. (Board stayed lit up from battery power). No apparent previous liquid damage, but did have a prior charging issue. Any ideas? I hate 3476 boards.