Random Reboots

[Blakkout47]

Hi, sorry if this is the wrong forum but I need help. Every now and then, my computer will randomly reboot. It turns off as if I've held the power button, and then turns back on. The first couple times it would reboot. One time it sat at my motherboard's welcome screen and just sat there, and now it doesn't boot at all. No video, now keyboard power. If it doesn't boot, I have to leave it off for about 10 minutes before I can boot it again.

I have ruled out overheating. It is pretty damn cold in here, I cleaned out the dust last night, and it rebooted with a temp checker open, all temps were below 40 C.

It seems to happen at random times, although the first few times were all when I was playing WoW. It has only happened once out of a game, and I was just sitting in windows with IRC and ventrilo open.

I've considered it to be a possible power supply issue, but I am not 100% convinced. I ran a stresstest (prime 95) and it did it fine, did not reboot, so being under load and not rebooting made me less convinced.

However I've noticed that some of my rails are very skewed. My 3.3 and my 5V rails are within range, however my + and - 12V rails are very very off. my +12V rail reads between +2.3V and +8V (8V was achieved under the stress test). My -12V rail is constantly at -16.97V. During a virus scan, my -5V went to -8.58V. I know that it is possible for speedfan to be wrong, so once I find my multimeter I'm going to test them again. Also in the BIOS all my rails read fine, which further convinces me speed fan is wrong.

Specs:
GIGABYTE GA-P35-DS3L LGA 775 Intel P35 Mobo
Intel Core 2 Duo E6850 Conroe 3.0GHz LGA 775 65W Dual-Core BX80557E6850
OCZ GameXStream OCZ700GXSSLI 700W ATX12V SLI Certified CrossFire Ready Active PFC PSU
G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) RAM
Western Digital Caviar Blue WD6400AAKS 640GB 7200 RPM SATA x2
SONY DRU840A and DRU710A DVD burners
EVGA nvidia GTX260

any help is greatly appreciated

 

[Blakkout47]

So, I can't find my multimeter, but looking at my PSU it shows that I have 4 +12V rails and what they're designated to. The plugs for my PSU have the same indicators that are on the lable, such as pci-e 1 and pci-e 2. So I'm curious if those correlate to the rails or if that is just for ease of installation. Also, my graphics card has a 36 amperage requirement, and my 12V rails are rated at 18A, but since it's getting 2 it's ok? but one is possibly shared so it's bad? but it's worked for a year? please help

 

[Blakkout47]

so i found a multimeter, and tested my rails while running prime95 to put my system at full load. my 3.3 and 5 rails were all fine, but all of my 12V rails were at 10-10.5V. I had a meter with a needle, so it wasn't the most exact, but it never broke 11V. All these readings are below the tolerance level for the +12V rail. However, while under full load, twice now, it has not rebooted.