Star Trek: The Next Generation
Williams, 1993I picked up a HUO STTNG this week. The right cannon would move extremely slow when a ball was loaded in it. I pulled it apart and cleaned the gummy residue that I know is an issue with these. When I put everything back together the right cannon starts rotating the second you turn on the power switch and will not stop. The switches on the right cannon do not work in test mode either. Any ideas what I should look for?
Check the molex connectors from the cannon wiring harness. Sounds like one came loose or you missed one when you worked on it. There are four or five of them IIRC.
I checked all of that. I didn't need to unplug any wiring to remove the shaft. Anything else I should look for?
The cannon will swing if it thinks there is a ball there. Check to make sure your optos are working in switch test. If that isn't it - go to the cannon test and make sure the home switch is activating.
The 2 switches for the cannon are not registering in switch test. The optos on the cannon do register in switch test. They are fine. I can't find any other switches that aren't working besides those two.
Quoted from SoCalPinballs:The 2 switches for the cannon are not registering in switch test. The optos on the cannon do register in switch test. They are fine. I can't find any other switches that aren't working besides those two.
You have to go into the cannon test - not switch test - they are special switches on this game.
When in the cannon test I hear the switch beep for both switches on the left cannon but nothing at all on the right cannon.
It should say home - then mark for each cannon, so that tells you that there is a break in the switches on the right side. Go to it!
Correction. The cannon switches DO work in cannon test. I must not have been doing it correctly before.
If the home and mark switches are working underneath, and the opto is working on top.... I'm not sure what else there is.
My guess is you have to redo the connectors on the opto board under the pf. Take them off and put them back on a few times (the grey one on the left) - see if it works after that.
Try this.
Swing the cannon out in switch test mode then open the coin door. (or do whatever to stop it from turning.
THEN, try the opto switch in the cannon, try the switch with the cannon in a few different locations. If you had a marginal harness and you have a break inside that insulation, it's possible the switch works fine in the home position, but is wonky during certain parts of the cannon rotation. I believe the cannon will keep rotating until it does a full rotation where it does not detect that switch opening. It could just be opening for a very short time.
Sounds like you have a marginal wiring harness that needs to be repaired or replaced.
The cannon just keeps rotating the second you turn the machine on. It doesn't matter if the coin door is open or closed. There is no way to stop it besides turning off the game or unplugging the cannon. This is a HUO game that is flawless and doesn't appear to have ever had any strange work done to it. It does have the laser cannon mod but I don't know if that has anything to do with it. The game worked fine before I removed the cannon to remove the gunk because it was turning so slow.
If you go into the menu the cannon will stop - I agree it may be a flaky harness - known to be a problem on this game.
I know it should do that but it will not stop even when I go to the menu. Strange I know. Nothing I do will stop it other than turning it off or unplugging the cabinet.
It sounds like you have a broken wire inside the harness . I had a similar problem with one that I shopped and fixed . It was driving me crazy ! The wire was broke inside the insulation ,so there was no way of really knowing until I pulled everything and checked each one . If it isn't the position switches or the opto , it has to be in the harness . You said it worked before you cleaned it ? The harnesses in these are notorious for causing problems.
Ok so now I unplugged all 3 connectors that run from the top of the cannon down below the playfield. As soon as I turn on the game the cannon begins rotating and wont stop. What now?
If it was a broken wire in the loom, why wont the cannon stop turning even in test mode with the door open?
Continuous power to the cannon motor? Short?
Quoted from SoCalPinballs:If it was a broken wire in the loom, why wont the cannon stop turning even in test mode with the door open?
Quoted from SoCalPinballs:If it was a broken wire in the loom, why wont the cannon stop turning even in test mode with the door open?
Good question - bad coin door switch?
Did you ever do this?
Quoted from SoCalPinballs:That makes sense. I will split open the loom and see if there is a broken wire.
I'm not sure I understand this. If the opto switch wire is broken or intermittent in the loom as the cannon turns, the switch opens and it thinks a ball is in there so it will keep rotating and firing.
Quoted from SoCalPinballs:If it was a broken wire in the loom, why wont the cannon stop turning even in test mode with the door open?
You've got 3 switches, home, mark and the opto. I'm 90% sure you are having an issue with your harness and the opto is the culprate.
I didn't split open the loom yet as it looks brand new. If the loom was bad why would the cannon start turning the second I turn the machine on even with the entire loom disconnected even when I put it in test mode. The cannon never stops turning. I can't imagine that would have anything to do with a bad cannon loom. I will switch the left side to right side when I get home just to confirm.
Optical switches are always shining a beam of light and being read by the receiver, with nothing blocking the beam the game reads the switch as closed. When something is blocking the light, like a ball in the cannon, the switch goes open to the game as the receiver is not reading the light from the transmitter. When the switch is opened, the game is interpreting that as a ball in the cannon.
When you are disconnecting the switch (disconnecting the entire loom), there is no beam of light being read so the game reads that as the switch is open, or, in this case, a ball is in the cannon.
Unplugging that switch is like perma sticking a ball in the cannon so it keeps swinging to try and eject it.
Quoted from SoCalPinballs:If the loom was bad why would the cannon start turning the second I turn the machine on even with the entire loom disconnected even when I put it in test mode.
I appreciate the help very much Jalpert. What I'm not understanding is why the cannon will not even stop in test mode with the door open. No other solenoids will fire in test mode so I know the door switch is good. Does this make sense that it would still rotate?
I just sold my STTNG 2 days ago, and I don't recall the behavior of the cannon with the door open. However, it is possible to me that the cannon motors aren't wired into the coin door switch, I'm just not sure about that either way.
Quoted from SoCalPinballs:I appreciate the help very much Jalpert. What I'm not understanding is why the cannon will not even stop in test mode with the door open. No other solenoids will fire in test mode so I know the door switch is good. Does this make sense that it would still rotate?
Maybe, with the game in test mode, put a ball in the working cannon and see if it swings out? It won't eject it because the coils will be disabled.
Quoted from jalpert:I just sold my STTNG 2 days ago, and I don't recall the behavior of the cannon with the door open. However, it is possible to me that the cannon motors aren't wired into the coin door switch, I'm just not sure about that either way.
The one I'm currently restoring sometimes stays put and sometimes the left cannon swings and the ball eject fires a few times.
You are swimming into the current if you continue with that harness. It is either the harness or your connector on the opto board.
I'm signing out on this thread since you want to do it your way...
Scott
Every STTNG cannon problem I have ever had was fixed by replacing the wiring harness. You have almost nothing to lose by going that route. They aren't expensive, they aren't difficult to install, and new ones are likely to be more durable anyway.
Are you referring to the opto boards under the playfield? I switched they from left to right and it didn't make a difference. I'm not sure what you mean about wanting to do it my way? I am looking for advice.
I have had this problem with other STTNG's as well and I am aware of the faulty harnesses. I will switch them when I get home and test it. All logic tells me that if the machine is in switch test and the cannon continues to move even with the harness unplugged something else is going on. Going into test mode should disable it.
Quoted from SoCalPinballs:Are you referring to the opto boards under the playfield? I switched they from left to right and it didn't make a difference. I'm not sure what you mean about wanting to do it my way? I am looking for advice.
The left right are for the inlane detect - the opto board I'm referring to is on the lower left - look at one of my posts above as far as which connector
If going into test mode should disable the cannon motors, and your cannon keeps swinging out, you have two sperate unrelated issues.
It sounds a little like you are trying to relate the two.
Honestly, sounds like normal behavior.
Quoted from SoCalPinballs:Going into test mode should disable it.
I switched the cannons from left to right and unplugged and plugged back in the connectors at the opto board. Same problem. The right cannon starts rotating the second you turn the game on.
How many times does it rotate? Once is normal.
With the harness plugged in, when the coil fires is the plunger sticking out at all? If that plunger doesn't snap back right away it can cause this. ( game doesn't think it ejected the ball)
It will not stop rotating at all. The plunger is not stuck. All optos and switches are working. The switches work great in launcher test but the cannon wont stop moving. Definitely not the switches, optos or wiring harness. I am stumped.
It has got to be one of those. I think you're missing something. The switches need to work so the cannon doesn't behave this way, and the harness is what connects the switches. If all your switches were working, odds are very very good your cannon wouldn't do this.
Quoted from SoCalPinballs:Definitely not the switches, optos or wiring harness. I am stumped.
I feel almost dirty for saying this, buy factory reset maybe?
The switches definitely work in cannon test and on switch test. I tried the factory reset just to see if that made a difference. Still the same.
What is really strange is the very instant you turn on the machine the right cannon starts rotating before any lights come on or the display comes on. The left cannon tests itself after a couple seconds when the machine starts to boot the way I have always seen in the past. It is like there is constant power to the right cannon.
I have a guy coming to see it tomorrow. It just frustrates me when I can't figure out something myself.
Quoted from SoCalPinballs:All logic tells me that if the machine is in switch test and the cannon continues to move even with the harness unplugged something else is going on. Going into test mode should disable it.
Totally agree. The other big clue is that you mentioned the canon is rotating even before the game boots up. The CPU clearly doesn't have control over it, so this wouldn't have anything to do with any switches (optos or otherwise).
You probably have a short somewhere which is causing power to get to the motor outside of the game's control. Look for a short/bad diode....
Good luck!
Andre
Wanna join the discussion? Please sign in to reply to this topic.
Great to see you're enjoying Pinside! Did you know Pinside is able to run without any 3rd-party banners or ads, thanks to the support from our visitors? Please consider a donation to Pinside and get anext to your username to show for it! Or better yet, subscribe to Pinside+!
This page was printed from https://pinside.com/pinball/forum/topic/sttng-cannon-wont-stop-turning and we tried optimising it for printing. Some page elements may have been deliberately hidden.
Scan the QR code on the left to jump to the URL this document was printed from.
Lake Elsinore, CA
