Randomly Restarting PC

Problem

PC is randomly restarting once every day or two. I could replicate it easily by playing Call of Duty 4 for a couple of minutes.

Cause

I haven’t found the cause yet.

The most likely cause of the shutdowns would be overheating. I took a spare 120mm fan and put it inside the rig’s aluminum case.

Still shuts down when playing COD4.

Tried to double check the heating problem. I downloaded Orthos Stress Prime and Furmark to stress test the rig.

It doesn’t shut down even if the load is a lot higher than what COD4 does to the system.

Power supply problem? I highly doubt it because I’m using a Corsair HX 520 PSU. Just to make sure, I switched the rails used by the video card.

Still shuts down when playing COD4.

Maybe it’s the drivers. So I uninstalled the drivers then used DriverSweeper to scrub the drivers clean. Reinstalled the latest ++ATI Catalyst drivers.

Still shuts down.

Maybe it’s the video card itself. Besides, it is a factory overclocked video card. So I switched it with my old video card, an nVidia 8800GTS 320MB card. Of course, I re-scrubbed the drivers again.

Still shuts down.

Maybe it’s a memory problem. Ran memtest86+ using a Ubuntu installer cd I have lying around.

No memory errors.

—

At this point, the only possible cause for the shutdown I could think of right now is the motherboard itself. It is a quality motherboard, but even high-end devices can have defects later in their lifetime.

Before I could decide to replace the board, I have to try one last risky thing: flashing the mobo BIOS. Downloaded the latest version and flashed the BIOS with it.

Still shut down after 1.5 hours of COD4.

Looks like I’m going to have to buy a new one these next few weeks. Now the board itself is pretty stable and wouldn’t require replacement; I’m just worried that a random shutdown would affect the other hardware (e.g. the Seagate drive I had RMA’ed last week).

[August 14 Update:]

Solution

Bought a new motherboard to replace current one. This time, I was able to run through the first act of CoD4 without experiencing any crashes.