I'm not 100% sure how the reset circuit works on this vintage of Stern game, but I can give you an educated guess.

If your reset relay is the type that pulls in and stays locked on until the end of the score reset sequence, then it is likely there is a switch on each score unit that is closed when the score unit is not at zero, and only opens when the unit is at zero. Each of these switches is wired in parallel, so if any one (or more) switches are closed, the reset relay will stay energized. Since all of your score units are back at zero, you probably have one or more score units where the zero switch is out of adjustment and is staying closed even though its score unit is at zero.

With the above circuit, there may also be a switch on the score motor that is wired in parallel with the zero switches. The score motor switch opens at the end of the cycle to ensure that the reset relay stays pulled in until the score motor is back at the home position.

If your reset relay is the type that latches on game start, and gets tripped at the end of the score reset sequence, then you likely still have a zero switch on each score unit, but with two important differences. First, each zero switch is open when the score unit is not at zero, and only closes when the score unit is at zero. Second, the switches are wired in series, not in parallel. When all the score units are back at zero, all of the zero switches should be closed, which will complete the circuit to the coil that trips the reset relay. If any one (or more) of these switches isn't making good contact and is staying open even when its score unit is at zero, you'll be stuck in reset.

With the above circuit, there may also be a switch on the score motor that is wired in series with the zero switches. The score motor switch closes at the end of the cycle to ensure that the reset relay doesn't trip until the score motor is back at the home position.

It's rather tedious because you have so many score units, but if either of the above is correct for your game, you should probably check the zero switch on each score unit and confirm that they are all operating as they should. Also, if there is a score motor switch in the circuit, you'll need to check that switch as well.

If you have a schematic, it can help you determine if either of the above circuits apply to your game, and it should also help you determine if there is a score motor switch involved.

- TimMe

What about the score motor switch to the right of the reset relay coil? Have you confirmed that it's closing and making good contact, and that there are no detached wires at the switch solder lugs?

If the score motor switch is OK, you'll probably want to start going over the circuit one section at a time. Here is one suggestion:

1. With the game on and the far-right score motor switch closed (I'm assuming that happens when the score motor is in the home position), run a direct jumper wire to the reset relay coil from the left-hand power bus, to confirm that the coil is actually working. If the coil doesn't energize, you either have a bad coil, or you have a circuit fault in the wiring that goes through the score motor switch. You can run a different jumper from the right-hand power bus to the other solder lug of the coil to figure out which problem you're dealing with.

2. If you can energize the coil with the left-hand direct power jumper wire, then you can use the same jumper to start applying power to the double-blade wiper of each score unit - these are acting as the zero switch for the score unit, and they should be conducting (switch closed) when the unit is at zero. Start with the score unit whose wiring goes directly to the reset relay coil, and work your way backward through the daisy-chain from there. Each time you touch the jumper wire to the double-blade wiper, the reset relay should energize. IMPORTANT: The score unit must be in the zero position for this test to work!

3. Keep checking each score unit in the chain until you hit the one where the relay no longer gets energized. Then you will know the circuit fault is somewhere between that score unit and the previous score unit you checked (that DID work), and you can focus on that part of the circuit.

- TimMe