according to manual microcomputer may be temporarily scrambled. Unplug microwave from 120volt outlet the plug back in this should reset the microwave according to manual.There is also a smart diagnostic service with a phone near the top of the microwave panel . when yo call LG customer information center At 1-800-243-0000. When instructed to do so by the call center agent hold the mouthpiece of your phone over the smart diagnosis logo on the control panel. I hope this helps