Did you verify that the CPU sees all switches closed and assigns them their correct #, or did you just see the "99" and not know there was more to the switch test?

Steve
System 80, not just a job, it's an adventure

Yeah, I went back through your thread and looked closer, then modified my post to omit everything but the switch test question. I hoped I would correct this before you found it but I was too slow.

Most forget or don't realize that there's more to the switch test. In switch test 18, when all the switches are open, you'll see a "99" in the credit window. Then, you can test each switch by closing it and see if the CPU sees them as closed and assigns them the right number. I've seen a game boot to attract mode but go wonky during game play and then lock up because the game saw two sets of strobe 4 lines and no strobe 5 (for example). So, I always verify that the switch assigned numbers match the numbers the CPU assigns the switch that's being tested. It may be nothing in the case of your game but it's worth a look. I wish you had another working CPU board to test with since it's still possible that the CPU is having logic issues. Still ... replacing a transistor isn't difficult either.

Steve
System 80, not just a job, it's an adventure

Nothing to see here. Dummy clicks send instead of close.

I would think this indicates that you have a CPU logic issue that's keeping the A relay driver transistor turned on. If you had a working CPU board to swap into your game you'd be able eliminate it as the cause.

I'm going to go under the assumption that the new boards operate the same as original one's do since I've never needed to buy a new one.

A shot in the dark question; have you replaced your A1J4 to A3J1 connector or if not, looked at it for bad/broken or alkaline damaged bifurcon connections? If you are running a new connector too, this next part will be of no help. IIRC, if there's a communication break between the CPU and driver board (A1J4-P to A3J1-P or A1J4-5 to A3J1-5), transistors (Q48 included) can get locked on. Since you have no way to play the game yet, are there other LD4 controlled or Z12 driver transistors locking lights on? This could be an indicator of a bad/broken connection.

Steve
System 80, not just a job, it's an adventure

Sorry I jumped into the thread so late, we could have stumbled onto your answer sooner. I usually steer clear of replacement aftermarket board threads but your problem didn't make any sense to me and got me curious. At least now you can play the game, good detective work.

Steve
System 80, not just a job, it's an adventure