The symptoms you describe suggest a mechanical problem with the swell pedal. When you move the swell pedal, does the shaft sticking out of the side of the swell box turn? Try disconnecting the lever from the swell box and turning the shaft by hand, it should
turn easily, and change the organ volume as it moves.?
I ended up after a couple of years with an m102 but it had some issues. i recently acquired another m102 in much better shape. It's only problem it seems is that the pedal seems to have on effect on volume. It plays at roughly the same full volume of the
old organ. the volume soft tab works and the drawbars all work. the lever behind the pedal works.?
any suggestion for next steps.... ie... a specific tube maybe? any suggestions would be appreciated.?