Bill Ory for Model Number PT970BM1BB My 4.5 year old GE Microwave PT970M1BB Buzzes Loudly when the door is shut. This microwave is built-in with an Oven below. Loud buzzing starts immediately when the door is shut. So far, I have replaced the Transformer, Magenetron & a plastic "Air-Cover" (basically a duct that goes between the Magenetron & the side wall of the microwave cooking chamber). I have also replaced a Diode that goes between the capacitor and the sheet metal of the microwave. The original "Air Cover" was melted on top so I assumed the Magnetron was overheating causing this problem. I just completed the replacement of all these parts and when I shut the door the buzzing starts and I see some "whisps" of smoke coming up from the magenetron. I am not sure if this is just because it is new and needs to break in a little and burn off some paint or if this is another symptom of the real problem. I called one of the sales folks and they looked up my problem and said that other Posts have indicated either a bad door switch or the control board for the microwave. Hopefully this will be a relatively cheap-fix since I have already sunk alot of money and time into this unit. Thanks for your help. Bill
Answer Hello Bill, It sounds like you have a bad control board or a shorted or pinched wire and will need to inspect the wiring. Read More... Answered by AppliancePartsPros.com | Wednesday, February 20, 2013