So I picked up a Power Mac G4 from a dumpster. Its a PowerMac 3,6 - that mirror drive edition. Anyway it won't start when the power button is pressed. However when I connect it to the 17" Apple Studio display (the one that does not have its own power cord) and press the power button that comes with the display then everything works, the computer runs fine. So the problem looks like the power button on the PowerMac is broken. Now when I disconnect the display and connect the USB keyboard with the power button, the PowerMac still won't start when I press the power button on the keyboard. Please any mac expert knows what this problem is ? I know the keyboard must work because I can start another PowerMac G4 with this keyboard.