During the summer, which is to say, when the ambient temperature is hot, my computer freezes up randomly. This -only- happens in the summers, when it's around 80 degrees or hotter in the house. During winter, it runs completely fine, without a hitch. This... cycle... been going on for nearly three years now, the entire time I've had the computer. Considering how often I have to hard-reboot it from lockups during the summer, it runs great at all other times.
The lockup happens sometimes instantaneously, sometimes with a bit of a stutter first, but there's never any real on-screen indication except that my mouse won't move anymore. Games simply halt on the spot - no visual artifacting or anything like that. If any sound was playing while it locked up, it either crackles into nothingness or repeats in the way that locked up computers tend to do. The HDD light on my case either goes completely solid and stays solid, or simply turns off and stays off. Fans continue to spin, however. There's no noticable change in the noises it makes.
Upon being rebooted, the computer runs fine again, as if nothing happened in the first place.
While it is much more likely to occur when the system is under load, I've experienced the lockup when I was doing nothing but leaving the computer idle, with only background programs running. The only real trend is that it only happens when it is hot in the house (ie, summertime.) - 80 degrees or higher, generally.
Actions I've taken:
This has been going on for three years now with no apparent degradation in how my computer runs during normal operation. You'd think it was fine, aside from the locking-up part.
Swapped out video card. No change. Still locks up.
Swapped out hard drive / windows install. No change. Still locks up.
Done a full RAM integrity test. No apparent issues.
I tried swapping out the RAM, but apparently I just don't have the right stuff on hand - everything I tried caused it to fail to boot.
Done a full HDD integrity test. No apparent issues there, either.
The case has, currently, two intake fans, and a third-party, midrange CPU heat sink/fan. I vacuum it out regularly, very little dust.
Typical heat levels during standard use, taken from Speedfan (With the exception of the MCP, which I grabbed off my BIOS during boot)
Mobo: EVGA 780i SLI FTW
CPU: Intel Q9300 Core 2 Quad 2.5ghz
GPU: Nvidia Geforce 9800 GTX+
I don't overclock my computer at all - everything is running factory specs.
So... yup :\ I'm completely confounded. Is it at all possible this is a motherboard issue?
Edited by SeeTea, 08 July 2011 - 11:34 PM.