How to Stop Noise in a DC Fan Motor

DC fans commonly known as PC case fans are designed with a sleeve bearing assembly. These fans are designed to work without the user being aware of their existence. However; fan motor noise is your first indication that the assembly is not perfect. DC fan motor noise occurs when the lubrication on the sleeve bearing shaft has dried up. Most users discard the fans and by new ones, unaware that these fans can be lubricated. Lubricating the DC fan motor will returns the fan to a quiet running state and prevent eventual malfunction.

Open the computer case. Use a bristled brush to remove dust buildup from the DC computer fans. Vacuum the dust from the case using a small attachment to fit into tiny cracks. Be careful not to scrape across the components in the case.

Remove the fan that is causing the noise. DC computer fans have a screw at each corner securing them to the case. Remove these screws with a Phillip's head screw driver.

Lay the fan on a flat work surface with the front facing up. Peel away the sticker at the center of the fan to reveal a small rubber plug. The rubber plug is the cap for the lubrication well.

Insert the head of a small flat screw driver between the rubber plug and the fan casing. Pry the plug out gently to expose the fan motor. Apply a single drop of 3-in-1 machine oil to the center of the lubrication well. Spin the fan with your fingers to lubricate the shaft inside. Reinstall the case fan.