The chips on the encoder are probably not available anymore, but there is a modern version. I can try to replace them for you. If there are enough people that need this encoder board, I can make a batch of new ones.
Have you cleaned and inspected the valve body and pneumatic delay on the motor/raise circuit? I'm trying to remember how my setup worked without the turret on, although I think I waited until it was all together. I think there should be a fair amount of air leaking, in the normal state to hold the turret down. When the solenoid gets activated, the hold-down air should stop and the up air and motor should start. I think there should be enough pressure to run the motor and the leak, but if not, I would try to stop the leak with my finger, no scratch that, something to plug the up air port. Another thing comes to mind, does the coil resistance on both solenoids match? Also, I seem to recall the aluminum cap with the electrical terminals, unscrews to reveal a disk with a small orifice under it which might be plugged. I can post a picture, if needed.
Your limit sensors short the sensor output wire to the sensor ground when activated. With only the sensor output tied to the IO board, the sensor shorts the voltage that is on the input to the sensor ground. The sensor ground needs to be tied to the IO board input ground to complete the circuit. Plus, normally an input doesn't have any voltage on it, so if you short the input to ground, nothing happens. To make this work, you need to tie the IO board's input supply (+5 V ?) to a resistor (2k Ohms ?) to the input. This brings the voltage on the input up. When the sensor activates it shorts it to ground or 0 V. Sometimes the IO board will have a pull up feature on the board to do this. When the IO board is powered up, can you see any voltage on the unconnected inputs?
I don't know anything about a Cubloc, but my wild guess here is that Mach and the Cubloc exchange a signal called a "charge pump", or I prefer "watchdog". It is a periodic pulse that is like the two saying to each other "are you there" ... "I'm here". Mach and Cubloc may check to see if the signal is valid and if not, they assume something is wrong and go into e-stop or shutdown. This may be another signal that needs to go through your IO board.
Kirk,
Kirk Wallace's Machine Shop