I was defrosting a item and everything was working fine then all of a sudden i did not hear the microwave going i looked at it and the timer was still counjting down but there was no noise i tested all the buttons and everything works on it except it sounds as if the motor is not running however it seems as if everything is working but i can not use it because the motor seems not to run is it a simple fix or do i have to but a new one it is not even a year old plesase help