I went to test my PSU (Xtreme Gear 800W ATX Power Supply model XG-P800) with my Coolmax PC/SPS/ Tester. All of the lights except the +3.3v and the -5v lights are on. My computer will turn on for about 5-10 seconds, with no signal to the monitor or any peripherals. After that it will shut off for about 5-10 seconds, then restart. I reset the CMOS, I have a new CPU, motherboard, case, heat sink, and RAM. Any ideas?