I may have hit a road block!! This might be over my head! So, this part is going to take a while......
I found out my transistor is good, Q31, for anyone that tries to work on one of these with out a schematic. I'll put all the transistors that I figured out below to help make it a little quicker for someone else later on.
I have a 15 to 20 second, then a 5V pulse that activates or closes the gate(?) on the transistor activating the coil for a second or two, over and over, while the game is in play. The sensors are good that are supposed to activate that solenoid! I switched them with a known good set from the machine to make sure.
So....I'm kind of lost now! I have some more guess's. But? That's about it! It's like the machine is stuck in a loop, just for that coil.
Without a schematic.....I now have to sit down, study the board, study the IC's and try to figure out how each one is working, then maybe start checking them up the line....If I can figure all of that out?!!
I'm trying to locate the chip, or whatever that opto sensor operates. I thought that would be a good start. Maybe the computer sees that opto as tripped(?) and is trying to clear the ball out of the way. This only happens in game play and with that solenoid(coil, I know, I know, I use the two words for the same thing. ) only. Since, I know the sensor and wiring are good, I'll try to find what's next in line in that direction too.
Anyhow....Here are the transistors and what they operate, in case someone needs this. They won't have to spend the same time I did figuring this part out.
Giving a list of wire colors is kind of pointless, Seems like each plug and system in the game are using the same colors for everything. And that's easy enough to figure out, just have to unplug all connectors when chasing wires. Dead End them all, and they are simple to trace with a meter.
Q20= Pebbles character coil
Q21= Fred character coil
Q23=BAMBAM character coil
Q24,Q25 operate left and right flippers, I'll Edit this later...
Q28=Ball Release coil
Q29=Dino Character coil
Q30=Barny character coil
Q31=Cave out hole kicker coil
I made my own descriptions, but it's simple enough to figure out.
I have the opto's almost figured out, I'll post that later....