My Eliminator Lighting E108 Double Derby will not move to the music. The lights stay on and never move with plenty of loud sound in the room. The sensitivity knob does not help by turning either way. It worked fine without grounding the housing from the rear ground screw many times from different outlets. I hooked up the motor to a 12v power supply and the motor moves. Do I need better grounding? Anyone have any ideas? I would greatly appreciate any ideas!!! Thank you!!!!