my laptop randomly started running very hot a few weeks ago... the fan's constantly alternate between max and medium speeds. it's only a little over a year old, and i'm looking for opinions. obviously it could be that a fan failed or something like that... i'm going to open it up once i get my hands on a screw driver small enough. but are there any other more common causes? this is after 15 minutes of a fan blowing under the laptop and i'm literally doing nothing but browsing OT.