A broken top limit and directional switch typically causes the motor to run constantly after the ram reaches its upper travel limit. Because the motor doesn't shut off, you'll typically hear a banging or hammering noise as the motor continues to run with the ram fully lifted.
Pull the trash compactor out of the cabinet and unplug the power cord. Remove the top panel and replace the top limit and directional switch. Reassemble the trash compactor, plug in the power cord and reinstall the trash compactor in the cabinet.
THESE REPAIRS MAY HELP SOLVE YOUR TRASH COMPACTOR PROBLEM
Replace the trash compactor top limit and directional switch
The top limit and directional switch stops the drive motor when the ram reaches its top travel limit. This switch also controls supply current going to the motor start windings to turn the motor clockwise to lower the ram and counter clockwise to lift the ram. Replace the top limit and directional switch if you hear rapid tamping when the ram returns to the top and the motor continues to run. You may also need to replace the top limit and directional switch if the motor won't start or the motor won't reverse directions when the reaches its bottom travel limit.