Power shuts off

CheeseMo

Honorable
Feb 27, 2013
4
0
10,510
Hi all! I just built my first PC from scratch by myself almost a week ago. Once I got it running with Win7, it ran for a couple of days with no issues. Now it shuts off and won't turn back on unless I unplug the power cable. I noticed that the time it takes to die decreases each time it get it running again.

Everything seems to be working properly short of the power failure. The voltage looks good in the BIOS but the 12V rail is reading just over 8V in hwmonitor (haven't verified with voltmeter). Temps don't go above 36C on anything. I also reconnected everything except for the CPU (and cooler).

At this point I have a feeling that it's the PSU, but I wanted to know what you guys thought. Does any one have any ideas on what could be causing this?

Specs:

Mobo: Gigabyte GA-990FXA-UD3
CPU: AMD FX8350
GPU: Zotac GeForce GT620 1GB
RAM: Ballistix (Crucial) 2x4GB DDR3-1333
PSU: Thermaltake TR600 (600W)
HDD: Toshiba 1TB
Case: Raidmax Viper (white)
CPU cooler: Coller Master Hyper 212 Plus
I also have an optical drive (just CD/DVD read/write).