I'm still working on restoring my 1972 Gottlieb King Rock. I'm about 95% there and working on smaller and smaller details.

I'm currently trying to iron out some weird inconsistencies in how the machine is handling coins.

First off, I have the manual and schematics, but as I had mentioned in a prior post, my machine does not match up to either when it comes to the coin handling setup.

For example, though they appear on the schematic and the manual, my machine does not have an X (2 Play Relay) or Y (2 Coins per play relay). It has only the W (3rd Chute Relay). The only jumper adjustment I have for pricing is a "Extra Chute Adjustment" that seems analogous to the "3rd Chute Adjustment" that is described in my manual. These are clearly not operator modifications as its clear that these features were never installed in my machine by the factory.

I have two coin chutes, and as far as I can tell, both are wired to the W relay and when a coin is inserted it adds a player and advances the replay counter by one (based on my 3rd Chute Adjustment setting being on 2 plays - it has no one coin one play option). So far so good... I plan on putting "25 cents for 2 plays" decals on the machine and all would be well. But here is the weird part...

If there are one or more credits on the Replay Counter wheel and the replay button is pressed, about 75% of the time the game will advance the player counter by one, decrement the Replay counter, BUT THEN ALSO ADVANCE THE REPLAY COUNTER back up again. So you end up with the same amount of credits on the machine even though you just spent one. But not always - sometimes it works fine.

From watching the relays fire, what seems to be happening is that upon pushing the Replay Button the S (start) relay fires, the score motor turns and the W relay trips which is advancing the Replay Counter. But not always, sometimes just the S relay fires and all is well - the credit wheel goes down one and stays down. At first I thought it was doing this 1 out of 3 times, which would tell me its something about the score motor, but its not that consistent. I have not been able to find a pattern except that it is much more consistently adding the credit back than it is operating properly.

I've posted the relevant parts of the schematic in case that helps... But keep in mind, I only have the W relay circuit in my machine, no X or Y...

I'm stumped... Anyone have any ideas?

- Gblaz

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