I have an Alienware m5790. The warranty has expired a little less than a year ago. Since day 1, it has been overheating and Alienware couldn't fix it. The CPU is constantly over 150 F. and the fan never comes on. The heat sink is not plugged, thermal grease is all good, video card and memory are all just fine. I believe that the fan or the fan controller is malfunctioning. Does anybody know how I can find out if it is one or the other?