This is a cross post, from the DH forum,
So I've resolved several issues on my project DH, to the point where the game boots and plays. Now I'm chasing down other problems. On power up/boot, the auto plunger coil pulses 4 times, also occasionally the gun launch coil will do the same. I know these coils are on the same voltage connection #2 & #3 schematically. One thing that I am wondering about since they can both be actuated by the ball launch switch, (the gun handle trigger switch #11,) and I assembled this game from parts, is there a diode missing from the mix some where that I failed to account for?
Thoughts and advice appreciated!

Bump on this, thanks.

Thinking I might have a partially broken wire on the gun chamber opto, so sometimes the machine thinks a ball is in the gun chamber on boot up, anyone else have something like this happen?

There was a break somewhere in one of the wires to the gun chamber opto that sometimes made contact, but mostly not. When it did complete the circuit usually randomly during a game the gun would start rotating and timers on features would not count down. I ran a new wire to bypass the faulty one and voila most of the game play problems have gone away, still have that pesky 4 pulses on the auto plunger at boot up though. Help?