[Holymoly]

Recently I've experienced a problem when booting up from cold. Occasionally when I switch on I can hear the fans running normally but the hard drive light doesn't come on the system just hangs. If I reset it can get so far then switch off again of its own accord (usually the first Windows screen with the blue progress lights - I'm using XP). To date it will eventually boot up. I've been in the case and there doesn't appear to be any loose power cables. I have two harddrives with the C: and E: drives sharing a partitioned 70gig drive and a separate D: storage drive. Does this sound like a problem with the PSU or a HDD controller?

[Fozzik]

Sounds a little more like the motherboard. It could be the power supply as well, but since the fans are spinning up and lights are coming on, the power supply is at least operating in some fashion when you're having the problem.

It could really be any number of things, though. To troubleshoot, I'd probably start by unplugging everything non-essential to boot...like all drives, all but one stick of RAM, all fans, etc. Then plug things back in one at a time (try switching to the other sticks of RAM by themselves to test each individually).

If the problem isn't consistent, it's going to be a bit harder to pin down...I'm not sure what to say about that other than it will likely get more consistent as time goes on.

[Holymoly]

Seems like it was an ailing PSU. One other thing turned up however. When the case was stripped out it was found that the 8800GTS graphics card still had the transportation film on it! This PC was almost 2.5 years old and the PSU had been trying to keep the GPU cool with the windows closed all this time. No wonder it was worn out.