Just recently, my Inspiron 5150 laptop has decided that when I turn the power off, it wants to run the fan! Sometimes it runs on an almost idle-speed, but most often it is running full blast. The moment I power up the laptop, the fan returns to normal operating speeds. If i plug in the power cord and charge it all the way, the fan turns off...but the moment i unplug it, the fan goes back on! I have absolutely no clue what is causing this. It's extremely annoying, as the battery dies quite quickly when I take my laptop with me and the loud fan is extremely, extremely annoying. Any ideas?