got the new power supply, found bad on button, fixed it and it powed up, put win 2000 disk in, partitioned, started formatting drive c. last i looked it was 35% when i came back 20 min. or so later, it had shut down on its own. turned it on and the keyboard lights for only a few sec and nothing on the monitor. ps running, cpu fan running, lights on the mobo on. can anyone help?