is my 6600gt dead?

i opened up my video cards heatsink and saw that my thermal paste needed to be replaced. i cleaned the gpu up and put some as3 on, but got some crap on the architecture that the gpu sits on. i tried to use alcohol to clean the stuff up, but there seemed to still be some stains on it that wouldnt come off. anyways, i put my heatsink back on and booted up my comp. i hooked my monitor onto my video card and the computer booted up to the main menu completely fine. however, i did not get the chance to test the video card with graphically demanding things and will not be able to for quite some time. right now, im trying to figure out whether or not my graphics card could be fried. could it still be messed up, even though it booted up fine onto the main menu? im kind of worried about these stains near the gpu.

If it works obviously it isn't hosed. If the stains arn't going through the core itself or none of the inards are exposed it should be fine.

alrighty. well, can anyone else confirm this?