Have a polar express locomotive that will no longer operate...my other locomotive works fine on the same track....the engine acts like it is shorted out....the remote has new batteries and. None of the functions work...no forward or reverse and no sound functions either...I Will admit the track is in need of cleaning but as I said other engine works fine...cleaned pic up on engine...everything looks fine but the locomotive will not operate.  The light on the locomotive is bright, and if I listen closely there is a slight buzz sound from the tender car.