The main reasons for the motor not rotating are: winding open circuit, lack of oil to hold the shaft, abnormal capacitor, etc. Judging from the maintenance practice of electric fans, the latter two faults are mostly. For non-rotating electric fans, my maintenance steps are to measure the plug, rotate the motor, measure the capacitance, and then process it.
The first step is to measure the operation of the electric fan and the speed regulating winding. Rotate the electric fan timer first. When you hear a click, the timer is normal. If there is no click, the timer is damaged. If there is no resistance value, it may be that the motor windings have been burnt and broken. For a motor with a thermal fuse, the thermal fuse may be an open circuit. You should also disassemble the motor and take a look. If it is only an open circuit, short-circuit the thermal fuse to return to normal. The gear switches are all damaged, but the possibility is unlikely.
The second step is to check whether it is holding the shaft, disassemble the electric fan guard, and rotate the motor shaft by hand. If it does not turn, it means that the motor is holding the shaft seriously. Disassemble the motor, first remove the oil and rust on the front and rear bushings and the motor shaft, and then add enough sewing machine oil to the linoleum of the front and rear bushings. Most electric fans can be trouble-free.
The third step is to measure the starting capacitance. If the motor shaft rotates flexibly, it is necessary to measure the starting capacitance of the electric fan motor. First of all, use a multimeter to measure the resistance value of the motor starting capacitor at both ends of the motor starting capacitor, the whole electric fan motor running, starting and speed regulating winding, that is, the resistance value of the black and yellow lead wires.