Mensagem original de: metallikcherries ,
From what you described my first guess would be the logic board. When you are in open firmware and the keyboard does not respond that could be a sign that the ports have stopped responding due to the failure. My second guess would be the processors. What I would try to do is try and start the computer using only 1 RAM slot. If you can try and boot to your system disc or your AHT (Apple Hardware Test) CD do that and see what happens. If none of the above work, I think you'll have to take it to an Apple store to get it looked at. good luck!