The typical blow-dryer is a pistol shaped unit consisting of a handle with switches; a circular housing containing an impeller (or fan); and a barrel 11/2 to 2 inches in diameter with a heating element inside. The impeller draws air in through a series of holes and passes it over the heating element while expelling it from the barrel. Replacement is the best answer for a faulty motor, heating element, or switch. However, minor repairs to the plug or cord are worthwhile. Unplug the appliance before working on it.
When a blow-dryer fails to operate at all when plugged into a functioning outlet, replace the plug before attempting any troubleshooting.
If the appliance still won’t operate, check the power cord. For this, you must open the housing. Remove the screws holding the halves of the housing together (sometimes the screws are hidden beneath a label). Slide the barrel off and part the housing halves with a screwdriver. Use a continuity tester to check the power cord. If the cord is defective, install a new one, soldering the bare ends to the switch mounting posts.
If the power cord is all right, the air intake grille or the impeller may be stuffed with hair, causing overheating and automatic shutdown. Open the housing and clean out the debris.
A defective cord may also be the problem if a dryer operates only when held in certain positions. Test and proceed as above.