lionel 6-22918 lionel backshop: connections

If you have one of these, pay no attention to the instructions I posted above.   Everything is mislabeled on my unit and the instruction sheet is wrong too.  to compound the confusion, the connections are not on a corner that looks like this picture, even in x-ray vision mode from above.  turn your unit upside down so you can see what color wires are coming from the terminals.  With the back shop in the front, as you lift the unit to turn it over, my red / black power  terminal is the one on the right, near the edge.  Now that I have power, I am hoping to get input on two items:

1) All the backshop equipment works but I have no sound and the doors don't seem to want to work.  Any ideas on these?

2) what is the new mother board supposed to fix?  Lionel still has these at $40 - is it worth the change out and could it be related to the items above?

thanks for any guidance.