I have a Genz Benz Shuttle 6.2 that sometimes has a high pitched whine when I start it up. After a bit, the whine fades and then goes away entirely. I noticed that it seemed to be coming from the side of the case, near the fan vents. If I blow a little onto the fan (through the vents), the fan spins up and the whine stops. It seems like the fan is malfunctioning. Is this a common problem with Shuttles? What's the remedy?