guys i removed the fan from the heat sink to clean the fan from all the dust that had accumulated on it anyway, i go to put it back on and now for some stupid reason it makes noise! what the hell did i do wrong putting it back on? i mean it looks pretty straight forward there are holes for the fan to be screwed into the heat sink and so whatever ducts are their in the heat sink i just slide the screw into the holes of the fan and tighten so did i do something wrong installing it? or what help!!!!!!