I have a Philips DSR 6000 SD DirecTivo unit that is probably 5 years old. It had worked fine until last night. About 11 PM last night, the screen flickered off, and it appeared as if the unit was rebooting (got the grey powering screen). It got part way through and restarted again (this happened about 4 times), and then the unit just died. When its plugged in, there's no lights on the front of the unit (though I can hear something spinning inside, probably the fan). I've tried a different plug but still nothing.

Do you think its a bad hard drive or power supply?