My computer keeps rebooting 2-5 seconds after i've turned it on

[Gumpen]

For these last couple of months i've had issues with BSODs. I blamed it on the RAMs and returned them to the store. While i was waiting for them to return, i borrowed my brother's RAMs, and it turned out i still got the BSODs. Anyway, i fixed the problem a few days ago when i updated most of my drivers.

Today i got my RAMs back. I switched them out with my brother's RAMs and booted the computer. it looked fine the first 2-5 seconds but then it turns off and boots again by itself a few seconds later.

I've had a similar issue before, and it turned out it was my heatsink which wasnt proberbly mounted. I checked it, and it might have been loose but i managed to fix it and now it should be mounted correctly. Still, the computer reboots after a couple of seconds.

Ive checked all the cables to see it any of them were loose
Ive tried to plug the videocard into another plug
Ive taken the CPU out and back in
Ive tried to switch out the RAMs one by one

Do you have any suggestions ???
Thanks in advance.

SPECS:

4x 1 GB Corsair XMS2 Dominator 1066 mHz
Gigabyte GA-EP35-DS3P Motherboard
OCZ StealthXStream PSU
Seagate Barracuda 7200.11 500 GB HD
Core 2 Quad Q6600 8 MB (Intel Boxed) CPU
ASUS EAH4870/HTDI (512 MB) GPU

[Saxon]

I looked over your mobo's memory supported list real quick and did not see it mentioned in there so that might be your problem. I would double check because I might of missed it
[url]http://www.gigabyte.us/FileList/MemorySupport/motherboard_memory_ga-ep35-ds3p_2.1.pdf[/url]

[Gumpen]

But this PC have been running great for half a year?

[yngndrw]

I have the same issue, only started when I updated the BIOS to the latest version.

Its really annoying. Previous to this I had a very slow "Pre-POST" time as well as the "Verifying DMI Pool Data" time, which is why I updated it. Oddly the computer is fine after it has booted up.

Using an EVGA x58.

[Gibo990]

Make sure the motherboard is correctly screwed into the case using standoffs, otherwise it will keep shorting out (which could be your problem although unlikely). Try unscrewing it and checking if you have standoffs there, if not put them in the correct holes and then attach the motherboard again.

Or take out the battery in the motherboard and leave it out for 5-10 mins, then put it back in and try again.

[JohnEdwards]

Seagate Barracuda [B]7200.11[/B]
think I found your problem alot of the .11 have high failure rates

[Gumpen]

Thanks for all your help. I'll look into it.