There are several common reasons why a dryer may stop working, and all of them can be repaired. The most common cause for a dryer not working is a blown thermal fuse. Replacement fuses are available at home maintenance stores, such as The Home Depot and Lowe's Parts Quick.
Other common problems involve the door switch and the drive belt; replacements for both parts are readily available at the same stores, and fixing either problem is relatively easy. A faulty drive motor, a bad main control panel or problems with the incoming electrical power supply are much less common and harder to diagnose. If the other items have been checked, the services of a professional may be required to fix the dryer.