Mark S Endicott , NY January 04, 2016 Appliance: KitchenAid Microwave Oven 1.8 Cubic Foot KCMS185JWH2 Kitchenaid Microwave Kcms185jwh2: 12 yr old kitchen aid counter top not cooking. How to replace Magnetron. Routine diagnostics found to be mag tube quoted customer est agreed ordered part installed 12/31/15 tested ok customer picked up Do-It-Yourself Rating: Repair Time Estimate: 30-60 minutes