I electrically tested the magnetron, diode and capacitor and determined both magnetron and diode were defective. Ordered replacement parts late on Friday (unfortunately Monday was Memorial Day) and order wasn't processed until Tues. Regardless, I received parts a little after noon on Thursday in upstate NY. Installed parts on Friday and microwave has a new lease on life. Job well done by AppliancePartsPros!! Repair was complicated a bit as the KitchenAid microwave doubles as a convection oven and is mounted in a double convection oven stack.