Have the Bachmann Baldwin 4 6 0 n scale steam loco, had a digitrax sdxn 136 sound decoder installed, after install, when on track,  loco does not move. Sound comes on, light  comes on, goes off when digitrax zepher express is put into reverse. Assigned adress 4 on quick decoder set up.  But no response from motor. Could it be that the wiring on the circuit board for motor wires correct? There are 6 wires running from motor and soldered to the circuit board, 4 black ones along top of motor from front of the loco  and 1 black and 1 red from motor at the back end. Tried to upload pic but couldnt. Also, is this circuit board old version? Bought a new Bachmann spectrum dcc tender,  see it has 6 pins standing proud from circuit board. Current board does not have that? The decoder wires have been soldered to tabs running along 1 edge of the board? I was wondering if I should swop out the old tender and circuit board and try the new one. But where do I attach the 6 wires running from loco to new circuit board. Diagrams I have seen say attach decoder wires to the 6 pins. Where do i attach the motor wires on the board? Or, is whatever issue there is with original tender  circuit board possibly fixable?

Bought the little loco 2cnd hand but once on the track, the side rod on right hand side fell off. After much fiddling & cursing, managed to get the 2 little sprues on the tiny plastic attachment which the rod connects onto the little "plastic housing" fixed to side of the loco. When placed back on track, was ok, as soon went in reverse , it fell off again..... I see the "attachment"  to which rod must connect is loose from side of the loco whereas on other side its not, i. e . on other side where there is no problem, that attachment is firmly fixed to side of the loco, it is not loose.  After googling , seems this is a issue with this loco. Is there a fix, please? Thanks