Hi all,
I am having a very strange problem with the smoke unit installed in one of the locos... the 39014, not that the model matters any way. I'll explain what it does.
When I start the loco, sound and lights are functioning normal - standstill or running. When I turn on the smoke unit, the lights are ON and OFF twice a second and no smoke is coming out of the chimney. Furthermore, when I increase the speed from a standstill with the smoke unit ON, the loco stops and goes as explained above for the lights - twice a second stop and go and again, no smoke is coming out of the unit... When the smoke unit is OFF, everything functions normally. I am not sure what is going on here... There seems to be a problem with the smoke unit, or some kind of short circuit... I am not sure. I cannot tell which smoke unit is installed in the loco, as it has been installed at purchase time by the dealer. I will bring it back to the shop, as the loco is still under warranty (not even 3 months old) and only the third time on the rails, but if somebody has an explanation for this weird behaviour, it would be appreciated.
Thanks for you help guys.

Tom is correct: you have a short circuit somewhere - either on the function lead from the decoder or else in the smoker itself. If, as Tom points out, you have the little wire tongue of the smoker pointing in the wrong direction, it's possible to have the sprung smoker contact make contact with both the wire tongue and the body of the smoker at the same time. If that looks ok and there's nothing else obvious try and sort it with an ohmeter before lighting up again - although the decoder outputs are reasonably protected from a short circuit (that's why the decoder is shutting down) it may not stand that sort of thing for too long.

cheers
Dennis