Totally anecdotal, but the first thing I did when I haa any single glitch out of my cannons, was proactively replace the harnesses. ZERO problems since. It just aint worth the troubleshooting or headaches.

From Bay Area.
Code Name Quantity Price/Ea. Total
GS-STTNGH-17067REV3 Top Gun Cable - Star Trek The Next Generation H-17067 Rev 3 (each)
2 $22.00 $44.00

And broken wire in harness to/from said Opto.

Correct.

Correct. They will go from open to close. Try it, its pretty self explanatory and you have 2 cannons to compare in the test. They should act exactly the same.

Yes, and no.

The opto uses a transmitter and receiver. When the cannon is at rest the test may fail if the opto is bad, but it can also pass if the harness that feeds them is intermittent and failing when the cannon moves.

The cannon swinging limits are registered via the 2 switches underneath, but,,, say ball enters and at rest cannon and the cycle starts but it 'looses' the ball due to a bad harness, it will not fire but simple go to the end of swing and back.

Harness is not hard to replace, nor is cleaning up the mechs while your disassembled. Also you want to partially wrap the harness around the shaft so that swinging will release tension as opposed to the factory way of creating tension on move.

Correct. Caveat though is that cannon swing and switch tests are two different tests.

So they are mutually exclusive.

Another trick is you can ohm out the harnesses while wiggling them to find intermittent breaks, but that is highly unreliable. The reason folks stock the harnesses is that it removes a big variable and a high failure point.

If you swap them and still have issues, you ruled out the main cause AND you have a spare set of harnesses for next time.

Good tip.

Bah 20 mins at the iron.

I'm of the why play around for hours troubleshooting a 25 year old part that has run its course. I'ts like troubleshooting original caps on a same vintage supply, just change and worry after.

If one wants to shoot down to the broken or intermittent wire have fun all well and good. But the next wire will be shortly behind.

4 breaks? Good fix/find!

I use lighted CoinTaker 12vdc flipper buttons, but I do not have a shaker.

Like the flipper button metal nut.