My Inspiron 5150 has a really loud fan--it often runs in high gear even when it has no reason to (a.k.a. it will be just sitting there with the screensaver on). I had the motherboard replaced this summer (after only a year of owning the computer) but this problem occured even before then, and the fan is clean. I ran the BIOS update to A38 but that's not helping. Other suggestions? I'm still under a service contract, so I can get any repairs I need...