I had this issue with my Whirlpool Gold model #UMC5200BAS06. At first it spun with the door open and after I continued to get several use out of it, it finally decided to not spin but still did it's countdown. I found a helpful video on YouTube and decided it wasn't going to hurt to try and switch out the door switches before I would call a repair man. So I order all three new door switch for it since I didn't have the tool to test which one worked and which one was bad. Turns out only the bottom door switch was bad which I just replaced it myself. It was $8 for three new door switch and $7 for shipping from Appliance Parts Pros.com Discount Appliance Parts. Probably would of been $10 if I didn't order the other two. But now I have replacement parts if I need them. Needless to say my microwave works and I only spent $15 bucks on it. ;)