video card looks staticy

ok heres what happend. i use a seperet fan to cool off my vid card that i have to turn on, and one day i was playing battlefield2 and i forgot to turn on the fan so i started to see little boxes every were like a bad signal tv channel, so i turned off my computer and took off the heat sink from the vid card and re did the thermal paste and now the whole moniter looks all mestut up like a realy bad signal channel on a tv. it might be static or i just burned it out. so is ther any what to fix this. and if my typeing is off well its just that i can hardly see on the screen