Microwave issue

Question

I have a kenmore over the range microwave. It is about 6 years old. I have never had any issues with it untill now. We have have a few issues with on and off arcing up by the top stirrer plate. We continued to use it and now it has a hole burned into the plate. I removed the unit and bleed out the voltage. I removed the stirrer motor and tested it and seems to be not working. Could this be the problem or do you think this is a result of another issue?