Our microwave will finish cooking and the display says "Food is Ready," but it continues to run. The light remains on, but the turntable stops and it is no longer actually heating. It will turn off when the door is opened, but begins running again when the door is closed again. Sometimes this is for just a second, sounding like a surge; sometimes it goes on for quite a while. At one point, it continued for so long that we unplugged it. It does not always do this, but is becoming more frequent. My husband checked the door switches with the multi-meter, and they seem to test okay. Could one still be going bad but test okay since the problem is intermittent? If it is in this "run" mode (but not cooking), the microwave responds correctly if I push buttons to actually cook again. If it's not the switches, could you suggest another problem to look for? Thanks!