|Dunno if beep ever worked.|
You can get some ideas from any fans or keyboard lights or hard/floppy drive blinks during post.
If the power supply now will not turn on then just connect one hard drive to the PS only and use paper clip to jump the two PS motherboard wires. Be sure you are on the low voltage 20/24 pin and on the correct pins. Plenty of how to's on web.
If your PS fan starts up and you test for voltage then suspect the on off button or the lan between them on the motherboard.
"Best Practices", Event viewer, host file, perfmon, antivirus, anti-spyware, Live CD's, backups, are in my top 10