Our M/W just began to intermittently work/not work with no obvious (noises/lack of noise, etc.) differences in operation. It gives all outward appearances of working; however, we have been ambushed a couple times when it failed to zap our food. It doesn't make any difference if we use the express settings or just punch in the time. Light comes on, turntable rotates, clock works - it just doesn't always heat, but sometimes it does. :confused:

Any assistance would be appreciated. Thanks in advance :)