Stopped microwaving no heat just a loud buzz, sounds like it’s working

Hi,

Check that the two door switches are operating OK and that they’re not loose, faulty or perhaps the door actuating latch is not operating them fully etc.

These switches control the power to the magnetron circuit which heats the food. They are also a safety mechanism that prevents harmful radiation escaping from the oven if the door is opened whilst it is operating by stopping the magnetron circuit from operating

Here’s the service manual for the microwave (I think). On p.51-52 it details how to test the switches and the interlock circuit.

The parts supplier linked above is only to show the switches, their location (click on the switch link) and their possible cost. If a switch is faulty and needs to be replaced, there are other suppliers online that may suit you better. Search online using the manufacturer’s part number only to get results.

If it is not the switches then the schematic on p.57 will help to find out what’s wrong.

Here’s a link that in general details how to test microwave ovens that may also help.

Be safety aware when working on microwave ovens. The HV capacitor can store >6000V DC for months even if the power has been disconnected for this length of time. This amount of voltage can seriously injure you. The HV capacitor needs to be correctly discharged as soon as it is accessible after the oven’s cover has been removed and before doing any further work inside the oven. If you don’t know what you’re doing then don’t do it! Contact a reputable, professional, appliance repair service and ask for a quote.