BTX Pentium D running XP Media Center activates fans but doesn't boot when powered on. Was running fine, turned off overnight, now will not boot. 4GB ram installed, tried with 1GB, 2GB and 0GB. No beeps when powered up with 0GB. -Tried integrated video connected and video card connected with no luck. -Replaced motherboard, same issue. -Also tried different processor when new MB installed. Same results. Went back to original Pent D. -Fans run full speed all the time. It was the power supply & the MB.