My video card stopped working how do i fix?

I own a e - GeForce 8600GT 512 mb and after about 2 to 3 years of fantastic visual response my video card stopped giving video to the screen and the fan on it spins hard when i start the computer up and then goes quiet and does the same again continously until i shut down the computer...what's wrong with it and be reminded i have no other video card at the moment so im trying to fix the card itself.|||it sounds like the fan is failing to do it Job hence the alternating speeds try removing the card checking that it not clogged up with dust , make shure that the fan bearing has not gone dry meaning that it warn and has become unbalanced, not spinning as fast as it should the card may have shut down to protect its self|||Put it in the oven... no seriously look it up on youtube