Hi All, I'll preface my remarks by stating that troubleshooting
a player system has always been most effectively accomplished via
a process of elimination. That process typically begins at the
vacuum source. In this case, the fact that other components in the
system are operating properly can be a bit deceptive.

Regarding Mike Lott's dilemma, the first step in troubleshooting
this problem should be determining if there is sufficient air flow
into the pump distributor box when the system is in the Play mode.
So, disconnect one of the two main vacuum supply hoses leading to the
expression devices and see if there's good air flow. (Vacuum level
can be deceiving because it could be high even though there's almost
no air flow.) If there is good air flow, the problem is related to
the expression devices. If not, the problem is related to the action
cut-out.

The feeling I get is that the action cut-out valve isn't working
properly. If it was, then no notes would play when the manual
expression buttons are pressed. To eliminate the action cut-out block,
and other components related to that block, as the source of the
problem, disconnected and plug the hose leading to the action cut-out
pouch in the pump distributor. If that gets the music playing again,
then the problem is related to the action cut-out block or the port
on the transmission that triggers the block. If there is still
insufficient air flow, then the problem is in the distributor --
which would be uncommon.

Musically,
John A Tuttle
Player-Care
Brick, New Jersey