2 days ago, my iBook G4 was working fine. The optical drive was acting up (occasional noises, having trouble ejecting discs) but no other problems. Then, suddenly, it stopped working. It simply does nothing when the power button is pressed. I have tried multiple outlets for the plug and it has sat, plugged in, for over 20 minutes. I have also tried booting with no battery. But it still does nothing. Any ideas on what to try? Thanks.