that doesn't work on this game ... and maybe not any of the gtb 1 player games that used trip relays for reset complete.

the schem appears to be drawn at the time just before DB1 and DB2 have tripped but the score reels have reset.

note the "zero position ball count unit" switch in the DB1/2 circuit is still closed, which it wouldn't be after the ball has been sent to the shooter (the ball count unit steps up when the ball rolls over the trough switch).

it's easiest to follow if you assume the score reels zeroed on any of the first 4 motor 1A pulses in the cycle - nothing else happens until motor 2B closes.

it's a bit more confusing if the last reel(s) zeroed on the 5th pulse when there's timing overlap between motors 1A, 2B and 4C switches - but the schem would be drawn at the instant the score reel zero switch were all closed but the magnetic field in the DBx coils hadn't built up enough to trip the relay.

it seems like a good time to draw the schem since a common issues would be the score reels aren't resetting, or they did but a reel zero switch didn't close so the reset sequence is stalled.

hmmm ... 1970 and they just designed a game called Psychedelic. We should probably be grateful the lines are reasonably straight and connect to something

I really have no idea if there was some consistent logic behind how the schems were drawn. If there was, it changed over the years.

there was an addendum to the "game reset, ball at shooter, and game powered off" rule of thumb. You sometimes needed to add in "and reset all trip relays and stepper units".

I think there's been cases where the schematic just appeared to be wrong, but it did depend on when you were looking. If the symbol was drawn with the game in the rule-of-thumb state, it would seem to be impossible to power a coil.

unless a schem or manual specifically says at what time the state was drawn, I've had better luck ignoring the rule-of-thumb. If I have access to the game, it's a lot faster to go look (turn score motor by hand, operate devices, etc.).

I can totally see how the schematic rules may have changed over time. You think you've got something that works in all cases and eventually you find a case where it doesn't. Anyone who's ever written code or used a web site has probably run into that.

Just look at the Gottlieb Score Motor for example. The original design dates to the late 40s I think but along the way they had to add S and L switch dog positions and do some other wacky stuff to squeeze all they could out of the base design.

As much as I'd like to assume that the schematics were all drawn in the same state I'm pretty sure I've run into other cases where they didn't make sense unless you put that assumption aside. Or maybe it was just me...