when you say "lifted up the fan" do you mean the heat-sink also? GPU's also have thermal compound that is used between the GPU heat spreader and the surface of the heat-sink. the factory thermal compound is often white/grey in color. when you reassemble the heat-sink/fan you need to clean the old thermal compound off and re-apply new compound to it, or the next time you start your machine your card will burn up in about 4 seconds.