Heres the problem Powermac G5 1.8 Dual, running well for 5 years. Had a loud crack sound like a CD case breaking. Machine goes off, no light when pushing power button there after. The crack sound happened after pulling out firewire pocket drive from the front firewire port. Do you think with these symptoms = Power supply Does a power supply fault make a crack sound? Could a new a power supply unit fix my problems? I could take a risk and buy a Power supply unit for £100, I could probably manage to install myself. Getting it fixed by an Apple engineer with parts and labour would cost more than its worth. Also what the odds some other part would be messed? I know the harddrive is working OK.