Help!!!! Have a Kenmore Smart Touch Sensor Micro-Hood (Model 721.80513600) that has woked fine until today. Suddenly the unit will not cut off- has the light and the interior cooking (not exhaust) fan running. You can open the door and the fan turns off, but the light is still on. Close the door and the fan and light are both on. This unit doesn't have an on/off button, but a clear or reset button. The only way to cut everything off is to unplug the unit, which is a royal pain since it is mounted above the cooktop. Left it unplugged for some time and tried replugging and "rebooting", but didn't help. Cannot find any problems with door latches etc. Any suggestions greatly appreciated. Thank you. :(