I have an issue with the x-wing cannon on star wars trilogy. The switches and motor seem to be functioning correctly in diagnostics and the cannon fires reliably from the diagnostics menu as well. In play, the cannon does not fire reliably. I wonder if reviewing the game logic might help me determine where the malfunction is since everything works correctly in test, but not play.

How complicated is reviewing game logic from a ROM?

#star-wars-trilogy

Thanks for the replies. I’m really excited to get some new ideas on how to troubleshoot. I have been working at this for 4 years and have basically worked myself back to square one…. but with lots of “experience”

The reed switch, home, and loaded switches all seem to be working and adjusted correctly. In diagnostic mode I can see that the cannon registers as loaded as expected. ‘Home’ is active until the X-wing pivots past the loading ramp, and the 3rd switch (Ready?) remains active until the very end the the X-wing pivot. Maybe unrelated, but this is about the spot that the xwing cannon might actually fire.

I can get more specific on diagnostics but here is a general summary of what I have experienced.

In play the ball loads at home mostly reliably. As it pivots I can hit the launch button and nothing happens. I can hit it again a few more times as the xwing continues to pivot and it fires often after the xwing has swung past the ideal cannon fire shot, hitting somewhere between the 3rd and 4th target from the left. Other times it won’t fire at all and eventually auto fires on the second pass.

In diagnostics sometimes the motor will not run after repeated start/stop while testing. The cannon coil fires 100% reliably in diagnostics including when the motor is activated/running. I believe if the problem was a cracked wire, this would not fire consistently.

The part of the motor that spins is a little loose but I’m not confident this is the issue.

There is a little resistance from the reed switch and cannon coil cables that might create some additional force on the motor but in diagnostic mode the motor handles some added resistance just fine. I’ve tried holding onto the cannon while running the motor to see if I could replicate the motor not functioning.

I have replaced the coil and wires leading from it down to the connector under the playfield.

I have replaced the reed switch and adjusted it. I did find that the reed switch was being activated by a nearby gate or some other metal nearby.

I replaced the motor since the original had a slightly loose post(?) but I later realized that the replacement motor had a slightly shorter post and was creating some uneven force between the motor and the X-wing rod. I just reinstalled the old motor again since I wasn’t sure how to make the new motor match the height needed.

I have not replaced the motor control board yet.

It looks like there was maybe some damage or someone replaced a couple of the solenoids. Q17,18, 25, 26 all show a little discoloration or damage. I tested each of them with a multimeter and they all showed similar resistance.

I noticed the neon bulb attached at the connector to the motor relay board would light up occasionally when testing. Then I broke that bulb and had to replace it.

Thanks again for your thoughts.

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Looking over your list of specific items, the closest is

“This is by far the most common, cannon enable switch, sometimes home switch)
Does the cannon rotate OK, but when you pull the trigger it sometimes won't fire?
Does the cannon rotate OK, but when you pull the trigger it never fires?
Does the cannon rotate OK, but you can only get the trigger to fire the ball in a very small area?”

The cannon mostly rotates ok in game mode. It does fire at times but not in the correct position. I thought I had ruled out a switch adjustment problem since in diagnostic mode the switches seem to open/close at the correct times. The reed switch seems to recognize the cannon is loaded at the correct time. The xwing mostly finds Home reliably. Enable seems to be showing open/closed at the right times as well.

I tried taping the Enable switch down so I could rule out this being the problem. It might have worked for a day but after messing with a couple things then trying to re-tape it, I had the same problem with the X-wing.

This may actually be a problem with the Enable switch position (sw 36). I'd like to confirm when the intended switch state at different positions of the x-wing pivot.

Position 1 (Home, not loaded)
Sw 35 - x-wing Home - Active
Sw 36 - x-wing Enable - Active
Sw 37 - Loaded - Inactive

When x-wing is loaded
Sw 37 => active

As x-wing pivots away from home
Sw 35 => Inactive - correctly adjusted this is only active when x-wing is in the position where a ball can be loaded from the ramp
Sw 36 => Inactive - unsure at what point this should switch from active to inactive

My initial assumption was that the cannon would only fire in game when
Sw 35 = Inactive - suggesting the cannon was no longer at home position
Sw 36 = Active - (possibly incorrectly) assuming x-wing cannon was 'enabled' to fire
Sw 37 = Active - there is a ball to fire

I think I was wrong about the ability to fire the cannon based on Sw 36 state. After adjusting the position of the plate that activates Sw 36 higher on the rod, sw 36 deactivates earlier. Now I can fire earlier. I think this part of the problem is solved now.

The last item I want to address is the motor not running consistently. In diagnostic I can replicate the problem readily. I run the motor, and stop occasionally. Sometimes after stopping, I am unable to restart the motor. It seems that I can sometimes get the motor to start again after wiggling things a little but this doesn't reliably work so I can't be certain I'm actually affecting anything.

I previously replaced Motor 24 VAC 6 RPM 3 w 60 Hz #041-5058-00 with the only replacement I could find #041-5048-00. This part has a shorter shaft so the cam link assemblies were no longer aligned and the link was at a somewhat sharp angle.

I will wait for feedback before considering re-installing the new motor.
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I adjusted Sw 36 so that it was INACTIVE in the window I wanted the x-wing cannon to fire and this resolved the firing problem after 4 YEARS

I'll summarize some of the steps I followed for others that encounter similar issues.

Problem: x-wing cannon would not fire reliably
Resolution: adjusted the cam link assembly (915-6649-00) so that sw 36 would switch to inactive earlier. It seems that sw 36 needs to be inactive in order to fire. I had thought that it needed to be active. I also bent the metal plate on the micro switch slightly (180-5119-02) which might have been an ok alternative to adjusting the position of the cam link assembly.

What I had failed to notice was that in gameplay, the cannon would fire reliably in a certain position, and reliably not fire when in another position. I may have been able to fire in the 'correct' window on the as the x-wing pivoted back to home due to a slight delay in sw 36 returning to Active.

Other things I tried which may be the source for others' x-wing cannon problems:
- Replaced sw 37 (reed switch) which might not recognize the ball when cannon is loaded
- replaced wiring from the cannon coil as the regular movement of the x-wing can crack wire over time
- tested solenoids

I did not need to try pinballplusMN excellent suggestion "When in game play when button doesn't fire ball quickly put into switch test asap and test Reed switch in gun to see if it senses ball.", but this is a good idea for the future.

PinRetail thank you for your summary of common problems and likely source. This was a huge help.