Nov 26, 2020· How To Repair A Hair Dryer . How to repair a hair dryer. common hair dryer repairs include servicing the switch, fan, heating element, and thermal cutout. servicing a switch: on/off, fan-speed, and heat switches all work in the same way. they control the current going to the hair dryer, the fan, or the elements. some switches have only two positions: on or off, high or.