What could be the problem and how can I fix it?

Brand: KDK
Solutions tried: Changing different plug point... not working

1) Make sure that the outlet you are using is hot. Plug a lamp or radio into the receptacle and if they work, the supply is not the failure.

Next pace to suspect is the switch. Then the cord from the plug back through the fan motor.

Burned out motor.

Do you have an electrical multi-meter to allow you to test the equipment?