[DANLUDLOW]

For the past few months microwave was intermittently making a humming noise during operation. Now the microwave stopped making the noise but is not warming food as it used to do. It takes longer periods of time for the food to warm. What is causing this problem?

[Gene]

Most likely the problem is a bad magnetron, but there is a small chance that the 1100W inverter (#21 on the diagram) is bad as well. I would replace the magnetron first.

- The magnetron Part number: AP3881382

- The 1100W inverter Part number: AP4364963

Here are the breakdown diagrams and Replacement parts for WHIRLPOOL GH9176XMQ0 Microwave Oven 1.8 Cu. Ft. | AppliancePartsPros.com

Gene.

[DANLUDLOW]

Does the magnetron come with installation instructions? Can you give me a link for the magnetron installation instructions?

[Gene]

As soon as you will remove the microwave from the cabinet and remove the outer case, you'll see how simple it is.

Gene.

[DANLUDLOW]

I know I need to unplug the microwave during this repair. Do I need to be concerned about high voltage while replacing the magnetron?

[Gene]

Yes. It has to be discharged. The instructions are attached to the reply.

Gene.

[DANLUDLOW]

Thank you for the discharging instructions. Do I also need to discharge the 1100 watt inverter board if I'm only replacing the magnetron? Do I discharge both terminals on the magnetron? From the instructions that you sent for discaharging the 1100 watt inverter board it looks like you use needle point pliers to discharge thru a resistor correct? If pliers are used; how do you recommend that I ground the pliers and to what? Can you send some instructions on how to test the magnetron with a voltage meter?

[Gene]

If the microwave has been unplugged for more than an hour it probably does need any discharging.

There is no any reliable instrumental test for the magnetron. That's why I mentioned two parts which could cause such problem.

Gene.