I purchased a refurb AGP Leadtek 6800GT off newegg a few days ago. After the card arrived, I installed it with ease.
Before we begin, let me dismiss a few easy fixes people might point out or suggest.
1. The card feeds off a 450watt PSU with only one optical drive hooked up to it. NOTHING on my comp is overclocked.
2. I've updated drivers/dx9 over three times.
3. The card shows no signs of overheating -- it idles at 52c.
Screenshots similar to THIS depict what my comp looks like seconds before a crash:
I've tested both Oblivion and 3dmark2006 (the same thing happens in 3dmark06). Each of these events occurs only minutes or seconds into gameplay. I'm almost sure my card is dead and I need to RMA it tomorrow.
Any advice, confirmation, or feedback would be appreciated =).