Hair blow dryers work by using a fan to blow a jet of air through a section of heated wires that are powered by a motor. Most hair dryers will automatically shut off if the device becomes too hot to avoid motor damage, but sometimes a dryer will randomly stop working. By troubleshooting the hair dryer, you can identify any small or average problems and usually fix them yourself and save money.
Plug in the hair dryer. Make sure the electrical outlet is on by pushing the "reset" button. If it still doesn't work, unplug the dryer and inspect the power cord to make sure it is securely lodged in both the dryer itself and the power plug. Look over the cord to make sure there are no nicks or tears in the protective wire covering.
Use a screwdriver to remove fasteners that are holding the two sides of the hair dryer together. Carefully separate the two sides without letting any of the fasteners fall out. Check the motor for any obvious heat damage and make sure the buttons on the dryer are working.
Observe the fan switch and heat switch using a multimeter. Look over the fan itself to make sure nothing is broken or stuck. Check the heating wires to make sure none of them are broken or oddly bent.
Remove hair, dust and debris from the intake grill. If the grill is clogged, it can reduce the flow of air into the hair dryer, causing it to overheat or work improperly.
Contact the manufacturer of the hair dryer to see where you can order extra replacement parts.