If the unit jams/hums...
1. Turn the unit off. After turning the unit off, remove anything that has fallen into the grinding chamber.
2. Turn the unit off. After turning the unit off, insert an "unjamming" tool, (if originally supplied with your unit) into the bottom and turn clockwise. Once the tool turns freely, remove whatever was causing the jam.
3. If the unit is dead, press the red reset button located on the bottom of the disposal - if the unit begins to hum and the reset trips again, it is still jammed. Repeat step #2 and #3.