hello everyone i have a old Hornby Margate Made 1993-1994 Princess elizabeth locomotive, the model is very jerkish on the rails and sometimes doesnt move at all, i checked to make sure everything is clean, the wheels, anything else that can pick up electricity, and it is, the motor runs fine when connected to anthor margate made chassis, Is there some kind of short circuit or issue with the chassis in general, or is it just a connection problem? the track is cleaned and everything. Awaiting a answer for this issue. thank you.