Ian, thanks for the info on the smoke unit the other day..
Whilst posting pictures.. Do you have one of the inside of a (recent-ish) one please? - The one I was dealing with, I put a new smoke unit in, and still nothing..
Turns out the loco will run on analogue, but not on a DCC system (address 0).. Stick 12V on the skates, engine runs, but only just over a volt on the smoke unit power-pins.. Looks like the internal electronics are 'smoked'.
After an idea of how much electronics are in it, and how easy to replace/repair/bypass it will be.
TIA,
PhilP.