gigabyte x58a-ud3r rev 2.0 random reboots

[markwal]

Long story short. I had gigabyte x58a-ud3r rev 1 motherboard and had to rma it awhile back they sent me a gigabyte x58a-ud3r rev2. Great!

So after I got it I put it all back together but once a week or so it would randomly reboot no reason never had this problem with the old board. 2 months later it's doing it everyday. I get no dumps, no blue screens it just reboots. Please I really need some ideas my ram is testing fine with mem86 I've actually run prime95 for hours and had no heat issues. I don't notice the front fan lights  dim or anything when it reboots so not sure about the psu cutting off and back on. Any ideas any of you could give me would be much appreciated.

Thank you.
 
System details
Ram 12 gigs  6 x 2gig OCZ3G1600LV6GK
intel i7 930
GA-X58A-UD3R rev2
Diamond ATI Radeon HD5770
PSU Thermaltake tr2RX 750W
Hard Drives 2 x st310005n1a1AS-RK 1 tera each non raid
OS Windows 7 64-bit sp1

[Dark Mantis]

Hi

Well I would first think of the memory or the power supply. That could be the mains supply that is browning out or your PSU is dipping.

When you said you ran Memtest did you do a thorough check ? One stick at a time for at least ten loops ?

How old is the PSU ?

Are you connected to the mains supply via a UPS ?

[Lsdmeasap]

Are you using the latest BIOS for the board?   If not I would start there

[markwal]

I didn't do memory test stick by stick I just let it run for over 24 hours last week came back fine.
Windows ram test came back fine also.
 PSU is 9 months old

It is connected to a ups, well was I thought that might be the problem so I unhooked it and have it plugged into another outlet with a surge protector atm. Still having the problem.

Bios is latest but not the beta version.

[markwal]

Just a little more info it is completely random and this system is always taxed because of what I use it for. Processor is never lower then 30% on any core at any given time usually around 50% My memory is almost always tacked at 12gigs. Sometimes it will run for days. After the last reboot 2 hours ago it's running very stable only thing I did is bump up my ram voltage. But before that I had multiple reboots after I just logged into windows also while I was upgrading to the new vmware workstation version which I just got installed. It's just completely random.

[Dark Mantis]

Well I would do what Lsdmeasap advised first and make sure that you are using the latest BIOS version.

Obviously it is not the mains supply then as the UPS would have ironed that out. It still could be a problem with the PSU though.

[markwal]

This morning it rebooted and then posted finished mem check went into bios to check cpu heat saw 33 then it rebooted on me! Must be power supply.

[Dark Mantis]

It would certainly sound like it I'm afraid.   Double check the connections first though before junking it.