the optical drive, both the IDE and power cable. Power up with it unplugged. Power off and plug it backin.
Running Windows xp. We had a power failure. When the power came back on and I rebooted, the dvd tray keeps opening and then immediately closing about every 15 secs. Machine is behind a surge protector.
I've rebooted, powered off ( unplugged ) and powered on and it still cycles. When I actually use it, say for a backup, it works fine.