GA-965P-DQ6 775 keeps rebooting

[Litestream]

A couple of days ago, I returned to my pc to see that it had rebooted and was installing backup bios all on it's own.

My pc is just under 4 years old and I have never had any hardware issues before.

The board is populated with 4x 1GB Corsair Dominator DDR2 6400 RAM chips
GAINWARD 8800GTS 640MB PCI-E Graphics card
INTEL CORE 2 DUO E6700 Processor
The Processor is cooled by a Thermaltake water cooling system which is fully functional.

Since the above issue, the pc will not boot at all. It displays the Gigabyte loading screen for a couple of seconds then reboots.

So far I have:
Replaced the CMOS battery and closed the jumper posts adjacent to the battery holder.
Tried another PCI-E graphics card.
Attached a different bootable hard drive.
Tried different RAM.

Anyone have any other suggestions please?

[Fatman]

Try a different psu...It could be on its way out.

[Dark Mantis]

It is quite possible as fatman says that it is the PSU so I would advise you to test it first. The easiest way is to watch this video and then follow it's instructions.

http://www.corsair.com/cinema/movie.aspx?id=1358543

[Litestream]

Thanks for your advice. I invested in a Corsair 750W modular power supply and connected it all up.

The fans started, the PC booted and loaded Windows. Everything seemed ok for a few minutes, then it restarted and hung when it got to the BIOS screen.

I switched the power off and booted it up again. This time it loaded Windows, so I tried updating the graphics drivers to the latest version and loaded the latest motherboard BIOS from the Gigabyte UK website.

I then loaded World of Warcraft and within a couple of minutes, the PC froze again.

Any ideas what else I should try?

[Dark Mantis]

I would clear the CMOS and then load the optimised BIOS settings. If it still doesn't play ball then I would check the temperatures. It could well be an overheating problem. Another thing worth checking would be the pins on the CPU socket. Make sure that none of them are bent even slightly.

What BIOS version are you running?

[Litestream]

Thanks for your reply.

I'm using version F13 of the BIOS.

The CPU is firmly bolted to the motherboard with the watercooling block and hasn't been touched since it was installed 4 years ago.

The CPU temperatures range between 26C and 31C under heavy loading. GPU temperature is 64C.

I'll try clearing the CMOS and see if that helps.

[Dark Mantis]

I'm using version F13 of the BIOS.

The CPU is firmly bolted to the motherboard with the watercooling block and hasn't been touched since it was installed 4 years ago.

The CPU temperatures range between 26C and 31C under heavy loading. GPU temperature is 64C.

Well you are using the latest BIOS version so no joy there.
The temperatures, have you checked recently or is that what they normally are? It's just that at four years old maybe the pump is not functioning fully.

[Litestream]

I just checked the temperatures before I posted. The pump is working fine, it was replaced about 6 months ago.

I followed your advice and it seems to be behaving at the moment, so thanks again

[Dark Mantis]

Fingers crossed then. Please let us know how it goes.
One more thing just sprung to mind in case of any further problems is that did you update the backup BIOS after updating the Main BIOS? In other words are they matching?

[Fatman]

You may need to up the voltages on the MCH a notch and maybe a touch on the DDR2?

[Litestream]

This morning, it gets to the Gigabyte logo screen but will not advance any further. I can't even access the BIOS.

Any other ideas please?

[Fatman]

Take out one of your ram modules, try either number 4 or try 3 and see if it will boot.

[Fatman]

Also what is the rated voltage on the modules and what is bios telling you? If bios is saying 1.8 (default) and the voltage on memory says 2.1 then set accordingly in the M.I.T section.

[Dark Mantis]

This morning, it gets to the Gigabyte logo screen but will not advance any further. I can't even access the BIOS.

Any other ideas please?

You are going to have to clear the CMOS again if you can't even access the BIOS, so do that first. Then make sure that the two BIOS versions match.
Previously you said that you changed the memory. Is it on the QVL of the manufacturer as compatible with this motherboard?

[Litestream]

I took the RAM modules out of slots 2 and 4, now the PC seems to boot perfectly. All of my RAM is Corsair DDR2 6400 Dominator. It would appear that one or both failed when the PSU started playing up.

I followed the link from the Corsair website to a memory test site. I'll check all of my RAM.