The selector knob and timer quit working on our GE dryer. We noticed the plastic selector knob was cracked inside when we pulled it off. We decided to order a new timer along with the selector knob just in case the new knob didn't solve the problem. We put on the new knob as easy as we pulled it off and the dryer would turn on again, however it was not going off in the selected amount of time it was supposed to. So it turns out we did need the timer part as well. These parts came in the mail in about 2 days so we were able to fix the problem before having to go to the laundry mat to dry clothes.