Quoted from Djshakes:I started working on this and got all the switches working except on opto and the Cannon switches. As you can see the ball keeps trying to stage as one opto in the vux isn't working. I have diagnosed it down to a connector that I will fix tonight. Then I might tackle the Cannon switches. If I get if fully functioning it's not going to be this cheap.
» YouTube video
sometimes the wiring that feeds up to the cannons goes bad just from all the twisting and turning and just needs to be replaced . Sounds like this could very well be the issue with the cannons on your game , pretty easy fix . Star Trek the Next Generation is a really good game , good luck with your sale.