Anthony R Phoenix , AZ June 26, 2020 Appliance: KitchenAid 30" Built-In Electric Combo Oven Thermal Convection KEMS308SSS04 Kitchenaid Oven Kems308sss04: Microwave will not heat. How to replace Inverter. Replaced magnetron and inverter. Would not have been possible if I didn't find the service guide online. Complex panel removal and opening of unit. Requires 2 torx bits as well as phillips screwdriver. Do-It-Yourself Rating: Repair Time Estimate: 1-2 hours