STTNG cannons - anyone have experience getting them to work correctly?

[arzoo]

I recently purchased a STTNG which I'm in the process of restoring. One thing I can't seem to get working correctly are the cannons. Basically I'm trying to adjust the cannons so that they don't allow firing the ball too early or too late in the rotation. For example, the left cannon will allow a shot as early as the Time Rift targets but it should not allow firing the ball before the Mission shot. The right cannon has the opposite problem, it should allow a shot as early as the Alpha ramp but it doesn't allow the ball to fire until the Neutral Zone.

Per the manual, under the L/R Launcher tests; "If the Mark switch is closed, the launcher should be in a position where it can't launch the ball." Running the test shows the Home and Mark switches opening and closing at the correct points. For example, on the left cannon, the Mark switch does not open until the cannon is pointing at the Missing shot. But when playing a game, the cannon can be fired much before that point.

So for the fun of it, I taped the Mark switch closed. I would assume the cannon should never be able to fire the ball. But that's not the case, with the Mark switch held closed at all times, the ball can still be fired. The only difference is if I don't fire the ball the cannon continues to rotate endlessly - it never fires the ball on it's own (before returning home). It seems the only thing the Mark switch controls it dumping the ball out of the cannon before it returns home (when the player fails to fire it).

That leaves the Home switch. Does the Home switch determine when the ball can and can't be fired? I tried bending the long blade on that switch and it does seem to have an effect. Is the manual totally wrong? Can anyone confirm this?