I was using my laptop on my lap, (as one does) and I must have held it in the perfect way to make one of the fans collide with the body. There was a very unnatural grinding sound that I figured must have been one of the fans rubbing against something. I powered it down, and left to go get a screwdriver. I pulled one screw out which let the corner of the case open. I thought "I should check to see if the restart fixed it instead of opening the whole damn thing", so I put the screw back and booted it up. I'm now typing this from my laptop with normal sounding fans. I think taking the one screw out and putting it back in relieved whatever pressure was on the fan. Very glad that my laptop didn't brick.