Can't you just jumper the "9TH. POS. UNITS UNIT" switch and score 1 pt repeatedly and see if the tens fires as well?

If you've jumpered (shorted) that switch correctly and the 10pt relay isn't firing, then as Billc479 said, you probably have a break in the wiring somewhere.

On the schematic snippet you posted, you're trying to jump the GR-BLK wire on one side of the "9TH. POS. UNITS UNIT" switch with the YEL-BL-RED wire on the other side of the same switch. Effectively, you're just shorting the switch, forcing it closed.

With that switch closed, every pulse from the N relay should fire the M relay....if everything's connected as it should be. That's assuming that N switch is good.

You can use your jumper to bypass (short) lengths of wire also, in case there's a break in the wire. For example, you could hook one end directly to the lug of the M relay that's not connected to the black wire, and the other end of the jumper to the left (on the schematic) switch tab of the "9th. Pos. Units Unit" switch. Both those points should have the same color wire (YEL-BL-RED). If pressing the N relay with your finger then made the M relay fire, you'd know you have a break in the YEL-BL-RED wire somewhere in the length that you jumped.

Hey durriti,
I don't have a schematic - what color is the vertical wire on the right side above the "Zero Pos. Balls to Play Unit" switch?

Just to make sure you understand the reasoning behind what we're doing here - the circuit that fires the M relay when the 1 pt. score reel is at 9 and you score 1 more pt. (N relay fires) is pretty simple: just 2 switches (N and 9th. Pos. Units Unit) and the M relay coil itself.

FC problem (resized).JPG

What we're trying to do with the jumpers is short one or both switches, effectively taking them out of the circuit, or forcing them closed, if you prefer to think of it that way.

Putting one end of the jumper where the red X is (non-black wire on the M relay) and putting the other end where the yellow X is, should make the M relay fire. You're just bypassing both switches and connecting the M relay coil straight to the other side of the power bus. (This assumes that some switches along the right vertical wire on the schematic are closed as well. They should be, or none of your scoring relays would work.) If you do this, don't leave the jumper connected long - you'll burn up the M relay coil.

If the M relay doesn't fire when you do this, you have a problem with the M relay coil itself.

If you keep one end of the jumper at the red X and put the other end where the green X is (GR-BLK wire), you're shorting the "9th. Pos. Units Unit" switch. That switch is on the units score reel, though the GR-BLK wire runs elsewhere. Let's assume that your N relay switches are all working as they should, (which means that the N switch on the right side of the schematic snippet above closes when you either score 1 pt. or press the N relay armature closed with your finger.)

IF that's true that the N relay switches are working correctly, and you are jumpered between the red and green X's:

- if the M relay DOES fire when the N relay fires, the problem is in the switch (or wiring) that you jumpered...namely the "9th. Pos. Units Unit" switch.

- if the M relay DOES NOT fire when the N relay fires, the problem would be in the N relay switch, which you have not jumpered.

The problem could also be in the wiring between the switches, not the actual switches themselves. Look very carefully at all the solder tabs - hopefully, it's something you can see visually.

If not, you can use the jumper wire to "replace" the wire between switches. Go between one switch tab (in the back) and the next on the schematic - effectively replacing the original wire with your jumper.

The trick is making sure you're on the right tabs, switches or wires, especially with those old, faded wire colors. Also make sure your switch contacts are clean and sliding past each other slightly when closing. Looking good visually is no guarantee of an electrical connection, though - that's why we're using the jumpers.