What specific game are you talking about? So you have replaced the pins on the driver board that drive this solenoid. When you intermittently ground the tab on the driver transistor associated with the outhole solenoid does it properly serve the ball? If it works fine, then replace the driver transistor it maybe weak. If grounding the driver transistor tab doesn't cause the ball to serve properly you have either a circuit path problem between the transistor and the coil or perhaps a bad coil. If you intermittently ground the coil tab opposite the diode lined side that should fire the coil and serve the ball if not the coil is bad.

Might want to check the fuse holder/fuse for tarnish.

Check the ball through and make sure nothing is slowing down the ball.

Are you using the correct coil? It's possible that the previous owner put a weaker coil into the machine by mistake.

Oh, I could I forget. If the driver board doesn't have a good ground you could have this problem. What this means is that you have to put in the ground mods on this machine. So before you do anything else, look up the ground mods and put them in.