"AC Fan" several problems typical in maintenance must pay extra attention to ensure the effectiveness of each component of the fan, in order to give effect to provide a strong guarantee, if energized, the fan motor does not rotate, we must first power cords, plugs, sockets and other one by one check, replace damaged, the next step to check the band switch or rheostat damaged condition or wire excuse. Replacing a damaged or absolve element, re-welding connection. Second, check the motor field coil broken off or open circuit (internal) When the connection ring broken off can be re-welding. But the internal circuit coil can only rewind coil.