No wonder you didn't see smoke coming out of the machine (if 5v was showing as 12v)
Either way, my A3000 green screens because of a leaky battery
My A500 did because of a burnt (I have no idea how) DRAM chip. Had to unsolder all of them and place sockets and play the game of elimination until I narrowed it down to the faulty one. Pain in the butt, but it worked. Ah, another trick to try with faulty DRAMs is this: piggy-back chips you know are NOT faulty on top of the soldered DRAMs, until you find a combination (of piggy-backing) that make the machine work, which points to the faulty chip(s)
Either way, good luck to all of us with dead 'migies!
