I had this problem before the knob breaks, then I used vise grips until the stem BROKE down to the nub. So I had to get a new timer. Found AppliancePartsPros.com and looked up the item and watched the video. Called them, talked to the nicest service person ( Sarah), and ordered the parts, The parts came quickly, waited a day or two to focus on the job No problem took all the screws off the back, and took a picture to make sure all wires were in the right place switched the wires with needle nose pliers. They were a little hard to remove but Finally, the wires were switched. Put it all back together.