lights and sound work? Check the motor connections and the motor functions. One of those little wires may be broken.
If you have not ran it for a while, you probably need to clean the wheels on both the locomotive and tender, and iinsure that your track is clean, especially if you live in a humid environment.
And I would like to suggest that you go back and edit your title - it's way too long.
I have a Bachmann Spectrum (Item #83804) HO USRA Light 2-10-2 w/Sound, which I run off of a MRC Tech6 2.0 Sound Controller that runs either DCC or DC Loco's. I have had it for a few years but I hardly run it at all. Today I put in on my layout for a quick run and it started to run fine but then "stopped" for no apparent reason. It still has all the sounds and the light works, but it won't run in forward or reverse. I disconnected the "Plug Ins" from the Tender that connect to the rear of the Locomotive and cleaned them with electronics contact cleaner in case there was some "Dirt" on the points but it still won't run. I also tried to reset it to factory settings by pressing SHIFT, the 9,9 on the controller, but that didn't work. I also tried to do a CV 8 reset? But that did not work either. Does anyone have any suggestions? The Engine is an older one but is just like new. As I said I do not run it much at all. Any help would be appreciated.Thanks!