Check the dryer vent
If the dryer isn't getting hot enough to dry clothes, this could indicate a problem with a clogged vent. Look at the outside dryer vent, and remove any debris that may have collected. Lack of heat or no heat at all also may require some dryer repair parts. The dryer's thermistor or heating element may be the culprits when the dryer isn't heating as it should.
Investigate the power supply
If the dryer refuses to turn on at all, check the power cord. If everything appears to be properly plugged in, check the home's circuit breakers for evidence of a possible power surge. Some dryer troubleshooting may be in order if the power supply looks connected. No power at all may be the sign of a faulty dryer timer or electronic circuit board, parts that are simple to replace.
Listen for dryer noises
Check the contents of the dryer drum to make sure there are no loose objects in the dryer. Common items that make noise include loose zippers, change and other items left in pockets. If there is no debris in the drum, the dryer may need a dryer blower fan blade replacement. When this blade is damaged, it typically makes loud banging or rattling noises.
Sears PartsDirect has a vast inventory of Jenn-Air dryer parts available to keep your machine up and running.