I just got a "new" (supposedly open box but never used) gp30 with DC and Soundtraxx.  Put it on the track (DCC) and selected "3"--everything seems to work, the sounds work, the lights work, but it doesn't MOVE.  The "engine" throttles up and down, but the wheels don't turn.  The instructions don't include information on the CVs.  I assume it's a simple problem--can anyone help?  How can I reset it to factory defaults?  If I can't get it to move, it's going back to the seller!

I have three older regular (white box) Bachmann diesel locomotives.  These were purchased new retail 25-30 years ago, never run and stored in a clean closet.  When I took them out recently to try them, they all ran horrible with the same problem.  They make a loud but regular rattling/rasping noise, although they do run and the lights work.  These units have the small motor mounted directly on one truck, with wires to the other (pickup only) truck.  If I can attach a video, I will do so and it will demonstrate how these units currently run.  I have lubricated the truck gears and removed/cleaned the motor brushes.  I have NOT taken the motors apart.  While they do run a little bit better, this obviously did not fix the problem!  Since I found this on 3 different locomotives (GP9, GP30, GP50) I assume this is a common problem.  Has anyone else encountered this, and if so, were you able to fix it?  I appreciate any suggestions!
Dave
PS Apparently I can't include even a tiny video (too large).  Sorry; hope this still makes sense.  If anyone knows of a way to show a short video, please let me know.