I know enough about computers to break them, but apparently not enough to fix them.
I moved the MOBO and HDD from my gateway LX6810 to an 'Ultra X-Blaster Black ATX Mid-Tower Case & Diablotek PHD 650W ATX Power Supply Bundle' that I had laying around. I moved it because when I installed the oft recommended Radeon 5670 video card, in the gateway case with its 400W PSU I received a boot error after the POST that implied insufficient power. Sorry I can't quote that for you. I also preferred the great airflow of the ULTRA case.
The video card performed wonderfully for about three hours, running Dragon Age II at full specs (DX11, 1680x1050 res, High Graphics Quality). Then the screen flickered and I received a message saying that the driver had suffered a catastrophic failure and recovered.
After that failure the amount of time that the card would run that game or Fallout: New Vegas without issue has been reduced to minutes, Fallout hasn't caused the card to fail but shows major screen glitching. I have turned down the graphics quality as low as it goes, same result.
I suspected overheating so I watched the Catalyst Control Center and saw that the card never goes over 35 deg. It idles at about 30. I double checked with GPU-z same temps. Additionally I put a finger to the card, it feels cool. I didn't take any temp info before the first several failures.
My machine runs the stock Nvidia GT 120 without issue, both games run fine. Also the Radeon seems to run with just the operating system fine.
some important info to note is that this case and PSU originally held a AMD athalon X2 MOBO and nvidia 8600. The 8600 suffered similar symptoms after running for a year (on almost 24/7/365). I assumed the 8600 had failed originally, but now that I have two card with similar symptoms I am beginning to question the PSU.
I have not updated the BIOS version, but I have an exhaust fan on the back of the case. heat does not appear to be an issue for any component in the build according to speedfan.
Boards can also kill cards but both are always costly and very frustrating so I suggest that you may as well replace the unit but you can try to check the volts using a software utility such as speed fan ect. Low will be like 11.5v on the 12v source. Spikes and dips even when the voltage is well above that ware changes are like .3v or more then you may as well replace the unit before it costs you more time and money. As for the board if new psu doesn't solve the problem then it is worth while to replace it. New cards are far from free.