1. The power indicator does not light and the fan does not turn. First check the power transformer and fuse, use a universal meter to measure the resistance value to see if the coil or fuse is burnt out. If it is short-circuited, replace the same type of transformer or fuse in time.
2. The power indicator is on, but the fan does not turn. When the power indicator light indicates that the high voltage circuit is properly powered, it may be that the fan has failed. First check if the bearing is severely worn and there is no foreign matter in the middle of the fan blade. If there is no problem, use a multimeter to measure whether the motor circuit has an open circuit. If there is a motor unit open circuit, replace the fan motor of the same specification.