Had the same thing happen jsut the other night, once i got into it i thought it was the harddrive I could hear it powering up and down over and over in the few secs in was on. If i unhooked the drive(which is brand new) the computer booted, i threw another psu in and all powered right up, so power supply went on mine, keep it in mind if nothing else comes up.
What size is the power supply? 300W is minimum recommended for that setup. A good 250W might handle it but it's iff'y because the large RAM and new HDs use a lot more current on the 5vdc than the older systems did.
The power supply rating will be on a label on one of it's covers visible inside the case.
Ep, glad to see you come back and tidy up...did want to ask a one day favor, I want to enhance my resume , was hoping you could make me administrator for a day, if so, take me right off since I won't be here to do anything, and don't know the slightest about the board, but it would be nice putting "served administrator osnn", if can do, THANKS