Well with the cover off does the fan on the vid card spin, touch it with your finger if you can not see it, does it start right up again after you stop it. You might need a case fan, and pointing the right way. all fans if you look closely, on the side have 2 arrows. One is rotation the other is the direction of the air flow. the rule is, if you are cooling one component ..ie processor have the arrow pointing at it, if multiple components, have the arrow pointing away, this way it is pushing air out the back of the pc and pulling in cool air from front vents over multiple componenets.