check the bios beep code here
www.bioscentral.com
turn the computer off
remove the power lead from the back
take the side off
remove the cmos battery
move the cmos jumper from pins 1 and 2 to pin 2 and 3 and the back to pins 1 and 2
replace the battery
put the side on
replug in the power lead
boot the computer
see if you can borrow a larger psu to try in it