Matthew L Severna Park , MD March 02, 2019 Appliance: Model GE MICROWAVE MODEL # PEM31DM4BB Microwave would not turn on with door shut countdown timer would work The door switch needed to be replaced. Here are a few tips that I could not find and figured out on my own. First off when you remove the microwave cover for some reason two of the back screws are not Phillips rather they are Torx with the center pin. No homeowner has this tool I promise. Here is that you do. Knock out the center pin with a small straight screw driver. Then use a T15 torx. Second thing I discovered is that once in there are actually 3 door switches. You need to look for the broken one. By broken one I mean the one that the actual small lever part is stick inside the switch. In my case it was the top door switch. This is a very simple fix even for someone with limited mechanical ability. Don't be afraid to try and save a ton of money. Do-It-Yourself Rating: Repair Time Estimate: 15-30 minutes