John for Model Number GH7145XFB1 My microwave just started to make the very loud noise which vibrates as well and I noticed it smelled on the inside. It also stopped heating. This was very sudden. It has never given me an minutes issue but now I cant use it. What would it be? I know it can be one of three things. I don't know if I should buy a new one or just put in the parts. Should I take it to a repair man (because a house call would cost a fortune). Is it worth repairing or replacing? BTW I don't know how to work on these things and don't know how to discharge anything to get it ready for repair. I do know how to replace pull it out and I am sure I can replace the parts by myself but what would you say is the best option at this point. The microwave is 16 years old. Would the capacitor make this kind of noise or would it be the Magnetron? The high voltage capasitor either works or it doesn't right? Isn't like a coil on a car, it either works or it doesnt? Please HELP
Answer Hello John. You most likely have a "high voltage" side malfunction. Transformer, diode, magnetron, Capacitor. You will need to be extremely careful if you decide to test the components with a multi meter, Very high residual voltage is present, so make sure you remove power to the microwave and short across the terminals on the capacitor. The magnetron should have a reading of less than 1 ohm resistance across the two terminals, and an "open" circuit between each terminal and chassis ground. The diode/rectifier should have a resistance reading in one direction only, no resistance, or resistance in both directions indicate a faulty diode. The primary winding on the transformer should read approximately 450 Ohms resistance, the secondary winding should read 80 ohms resistance, and the filament transformer should read 100 ohms resistance. All of these are +- 10%. If all the readings are proper and in range, replace the magnetron. Read More... Answered by AppliancePartsPros.com | Monday, January 4, 2016