Microwave shuts off after a few seconds. My Microwave now shuts off after about three seconds of

Question

My Microwave now shuts off after about three seconds of cooking. All of the lights light up for around 10 seconds, and then it resets to the time/date setup prompt. It does it every time now. For months before, it would randomly shut down in the same manner while cooking, but not at the three second mark, and not every time.Please help.