Re: My BFG 6800GT dying? (Unique situation)
Youre right it might voied your warranty to take off the heatsink but it may be the problem. My card used a thermal pad originally. The thermal pad gets somewhat abused from constant heat and relaxes into a compressed state.
This makes it lose some contact pressure with the heatsink and graphics core.
Cleaning it off and replacing it with a good application of as5 will fix it.
That leaves you with a dilemna of whther to risk it and risk voiding your warranty. I did replace my thermal pad this way last year or so, it was completely shot.