Carol B Somerville , TX July 31, 2015 Appliance: Amana Microwave D1200 Amana Microwave D1200: My jennair is aprox 30 y o the knobs wore out stripped out. How to replace Knob, Thermostat. Ordered new ones they worked out really great... 1 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes