Quoted from Robotworkshop:At some point I'll want to install fresh sets but since it moves so much they should be made with the super flexible wires.
I honestly believe the cannon harness is more robust that most people think. Several of you are probably already shanking your and saying Pin_Guy has finally lost his marbles .... but hear me out.
Before restoring my STTNG I read a lot of information on this and my machine also had a harness that was questionably repaired so I spent a good deal of time investigating this to answer the "Why" question on this high failure rate and I concluded the following:
1) The cannon on this game does rotate yes, but it only moves around 45 degrees back and forth a few time per game if it moves at all.
2) The cannon harness itself really doesn't twist at all but instead gently moves back and forth with roughly 1" of travel per cycle on a cable that's fairly long in length.
3) If the cannon assembly is put together wrong, or the cable is routed incorrectly, or worse both of these things happen at the same time then a great deal of stress will be put on the cannon wires and they will likely break in a short amount of time.
4) My damaged cable that was cut apart and repaired was the likely result of a canon repair that involved removing the cannon from the game and not properly routing the cable when it was reinstalled. The cable in the other canon appeared to be original and that cannon looked like it had never been worked on but like many other parts of this machine it had its own intermittent issues.
Fact: Replacing this cable fixes almost all cannon issues; this is undeniable.
But saying that the cable wiring was the issue is shortsighted and ignores corroded connectors and cracked solder joints as likely causes even though these are the two biggest issues you find on these older machines; replacing the cable corrects all of these as this cable has eight wires all of which are soldered in place on the cannon side and go to three connectors under the playfield. By merely replacing this cable you just cycled all three connectors (minor cleaning action) and redid all eight of the solder points; any of which could have been the actual issue. Lets not forget that the actual metal part of the cannon that all of the parts with soldered on wires connects to contains a baby ball trough with optos on each side and a high powered AE23-800 coil which makes this whole mechanism a high vibration device.
Based on my own research and conclusions in this matter the original cannon loom was removed, cleaned, inspected, and reinstalled back in my machine during the complete restoration on my own machine where it is working flawlessly after 28 years in service.