power supply surging
Custom built desktop in a Raidmax case
Motherboard ASUS P5B-E
CPU Intel Core 2 Quad 6600
Video EVGA 8800GT
Power supply at time of failure Antec Trio 650Watt
2 internal SATA hard drives, 1 DVD
I had windows 7 installed, the computer was booting up and down normally, no obvious issues. I left it in "sleep" mode and when I returned (2 or 3 hours later)the power supply was surging ~ once per second (as noticed via the fans and lights) and out to the usb mouse.
After a check over I chose to replace the power supply. The replacement power supply is a Raidmax Volcano 630 Watt. Once in place and powered up the symptoms are the same. There are no POST beeps and the computer does not enter BIOS stage.
I have selectively disconnected power to HDD's, DVD, video, fans ... The power supply
I noticed a similar thread here - but from what I had read that person had not changed the power supply.
What's next in troubleshooting this problem, what would indicate a motherboard or CPU issue (motherboard vs CPU)?
I appreciate any assistance!