See all that dust and lint and whatnot? That's bad. Get rid of it, and use canned air to blow out the fan. Fold the fan blades still and move the nozzle of the canned air around the motor housing, where the round sticker is. If you point the nozzle into the rectangular slot and use it to spin the fan, you can actually spin it faster than is was designed to go, and damage the bearings.