The electric fan can be solved by replacing the bearing or cleaning the lubrication grease, replacing the new motor or a new capacitor.
If the motor bearing is worn and dry, the bearing should be replaced or the lubricating grease should be cleaned and added. In the case of no power, the fan blade or shaft can be moved by hand to see if it can be rotated flexibly. If the rotation is flexible, it indicates that there is no problem.
Knock the rotor stator and rotor, you can first loosen the fixing screws, use the wooden stick to knock the rotating shaft around and around, until you can turn flexible, and then gradually tighten the fixing screws diagonally.
This page is taken from experience without authorization