Do-It-Yourself Story

Push buttons are membrane-type. The wiring inside the membrane corrodes over time (and heat and moisture) until it just doesn't work at all. The membrane is integrated with the top plastic panel - not separately replaceable. Replaced the control panel that's on the top of the door. Easy to fix! Only gotcha is that you have to take off the cover of the control box (inside the door) and slide the locking bar out on the connector for the ribbon cable - the cable doesn't just push in, you have to release/relock that locking bar. Remember to get a new vent seal and install it into the new control panel, or this repair won't last long!