Tom P Unionville , MO July 08, 2018 Appliance: Model GTDP220EF1WW Thought it was the timer, turned out to be the knob. Turned the timer-didn't feel right-so thought the timer was bad, turns out I need a new knob. The stem cracked in half even though it has a metal insert. The fix itself was easy enough. About 5 minutes after watching the video. Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes