Thank you for your reply.  I have the owner's manual and a Bachmann "DC Wiring Connection" diagram for the 4-4-0 but neither shows how to get inside the boiler tube to access the PC boards.  I cannot find any screws on the outside to open up the tube and I do not see a way to remove the smoke box front to access the end entrance to the boiler tube. From what I see all the control PC boards are inside the boiler tube.  If there is other Bachmann information available I would like to find out how I can get a copy because repair will be - I believe - impossoble with access to the boards to trace wires.

I bought a non working used 4-4-0 at a train show with the hope of getting it running and converting it to radio control battery power.  The previous owner tried to do the same but was unable to complete a working conversion.  I have the Bachmann RC Wiring Connection diagram which shows the control boards  I have removed the running gear from the boiler but I do not know how to access the control boards in the boiler.I want to trace each wire to know where I need to make my hookups from the tender. Can someone please tell me how to access the control boards.  Thank you