System won't boot at all

[bz2h]

I am putting together a computer from old parts, but the system refuses to boot. All the fans works, although the CPU fan spins really loud, presumebly at top speed. But there is no power at all to the hard drive and optical drive, i.e. i hear no sound from hard drive and the optical drive does not light up nor will it open. The mouse and keyboard both turns on. There is no beeping sound, and the indicator light on the PSU (it's a stock one from Compaq) flashes on and off. Is this a PSU problem or is the motherboard malfunctioning? Thanks

 

[vigilante212]

Remove everything except the ram. See if it posts a message when you start it up if not you need to reseat the ram. Then Check each part one at a time.

 

[bz2h]

Remove everything except the ram. See if it posts a message when you start it up if not you need to reseat the ram. Then Check each part one at a time.

The RAM thing doesn't seem to make much of a difference. After I removed the IDE connectors of the hard drive, the computer seems to be rebooting it self every 2 sec or so (from what I can gather by the sound the hard drive is making and a small beep). Although the optical drive only open/closes when it is disconnected from the MB and only has power. Any idea what's going on?