My 4 Square is so close to being right. The 0-9 is now working perfectly, and I FINALLY found the broken solder joint on the ground that was preventing the lit 100 pt center bumper from scoring. However:

For anyone familiar with the game, should the center pop bumper trigger the alternating relay? Right now when it's lit it scores and chimes, but unlit it just pops (that feels wrong to me). I just want to make sure I'm not chasing something that is t there if that is the way it's supposed to work. The other two pops alternate it, which seems more right.

I've traced it a bit more since posting this. Yes, the alternating relay fires with both the 1 and the 10 point relays. From that video that Chris posted (thanks Chris!) I think the behavior of it is that the center pop if unlit, should score something (not sure if 1 or 10) and alternate. If it is lit for 100 it should stay lit after scoring.

So now I'm down to the fact that the center pop when not lit isn't scoring anything (scores fine when lit), and I don't think that is right. And the alternating relay issue is just a result of that pop not scoring anything.

And I have to admit, I'm not even totally sure how an EM scores at all, but I'm working on it

Found it!!! And what an adventure this little game has been.

My real problem came down to the game not scoring those 10 points when the unlit center pop was beig hit. I finally found the switch in the alternating relay that although it was closed, didn't have continuity. I hit it with a meter, nothing. Filed it down, and the occasional beep from the meter. Got it cleaned, adjusted, and now it scores the 10 points just fine.

Thanks for the help. And thanks everyone else for the trough help, the 0-9 help, and the general wealth of helpful information hat you all have left scattered in poss over the years.

Dave