General 

Problem

 

Possible  Cause 

 

Recommended Action

Motor Noise                        Firstly determine if the noise is electrical or mechanical.                         If the noise doesn't stop instantly, but runs down with the motor, the problem is more likely to be mechanical, generally the bearings; see Mechanical section: If the motor is switched off and the noise stops instantly the problem is more likely to be electrical;  see Electrical section.