I recently purchased an SDN144A0 sound decoder for my Atlas N scale Dash 8 locomotive. The problem isn't with the functions of the sound, thought it is not that loud in comparison with some of the other brands. That is besides the point. The issue I am having is there is no movement. The motor will spin and the wheel will move. I ran it many times pre decoder instillation. Now nothing but sound and lights. What should I do?