I have a dell precision model m50. I recently had a fan replaced as I thought the bearings had gone (even though the laptop isn't very old), the fans were also cleaned and cooling gel was put on them. As soon as I got home I noticed that still one of the fans doesn't work (I think it's the same one)... it doesn't even try. One of the fans kicks in and is very quiet but because its working on its own within a few seconds it goes really fast and gets noisy. My laptop doesnt ever crash from overheating but I do have problems watching videos e.g. YouTube which is what I use the laptop for. Does anybody know what the problem is and how I should go about fixing it? It's just confused me.