Michael S Stuart , FL May 04, 2015 Appliance: Frigidaire Microwave Hood Combo FPBM189KFC Frigidaire Microwave Fpbm189kfc: Microwave working not heating. How to replace Magnetron (Microwave). My Frigidaire microwave less than 4 years old was working but not heating. During the actual process it was also making a loud humming type noise Replaced the Magnetron and voila the Microwave is happy again. 7 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: 30-60 minutes