Door switch
If the door switch or the door-switch actuator is defective, the dryer won't work and you need to replace the failed component. The switch is inside the dryer main housing near the door frame. Sometimes you need to raise or open the top or front of the dryer to reach the switch. To determine if the door switch has failed, watch the part testing video at the link on the bottom of this page.
Thermal fuse
On many dryers, there's a thermal fuse (a heat-sensitive fuse that blows if the dryer overheats) mounted to the exhaust duct inside the back cover panel. The fuse is about an inch long. It's usually embedded in black resin and mounted in a white plastic housing.
If the fuse has blown, it has no continuity. When this happens, your dryer either just stops heating, or it doesn't work at all. Be sure to inspect the venting/heating system before replacing the fuse to put the dryer back into operation. (You can't re-set this type of fuse.) To determine if the thermal fuse has blown out, watch the part testing video at the bottom of this page.
Wiring
Often the main wiring connection from the house, at the dryer, burns and the connection breaks. In this has happened to your dryer, you need to replace the power cord and the terminal block inside the dryer to which the wire is attached.
http://www.repairclinic.com/Dryer-Troubleshooting?red=Dryer-Repair-Help#repairHelpVideoTabs