Microwave Not Heating? Try This Simple Test
An effective way to check a microwave if it's working correctly, is to take a cup of water. Of course, you have to look at the model number, the the manual that comes with it, but it will tell you how long it should take to boil a cup of water. Eight ounces, 12 ounces, 14. So put the cup in and you can put a wooden starter in there if you like as well too, for this particular model, it's two minutes.
Start, and now I'm gonna wait two minutes, and in two minutes I'll take it out and it should be boiling or close to boiling. So we'll be right back in two minutes. Alright, so our time is up. Let's take the cup out of the microwave. Oh, you can feel it's warm. I don't think it's as warm as it's supposed to be though.
So this water. And inside the cup is 140 degrees, which means the microwave looks perfect, it's operating, however, it is not heating as it's supposed to be. So what is the only thing that can cause a microwave not heating like it's supposed to be in a glass when you do the test is the magnetron. So this microwave is not working and it's on its way out.