May or may not be an issue, but check the microswitch on the side of the cannon itself.

The lugs on the switch can bend and make contact. Which would fire the cannon.

Worth a look.

Dave.

Is it possible the game is loading the cannon when it shouldn't be loaded? If the right ramp cannon diverter was stuck down this would happen. Does the games skull voice say to fire the cannonade is the right cannon flasher lit?

Played a fresh out of box Premium yesterday with the same issue.
Cannon auto fired down the left spinner lane almost everytime.

VERY FRUSTRATING

I guess you could call stern. The support staff is there right now.

Must have been at lunch. They have always picked up very fast when I have called.

Report back your findings on the SW 62 test. Also how fast is your cannon moving? Is it really slow? Perhaps SW times out before the cannon gets to the TNT targets.

Tighten the screws on prox switch. I also had this problem after I tried to remove Canon mounting bracket to replace motor. You may have to loosen the mount screws and adjusts the bracket so it's closer to the switch.

There was another thread on common cannon issues which was very helpful. Stern has had great tech support with all my new pins.

Here's a pic of bracket.

a712f4c17c3051ad36799ee1017f02a3.jpg

I just got AC/DC Premium last night and am having the same issue. Is there an update on how to correct this?

Same Here my Canon is randomly Autofiring as well I just got the game today.

Just to add more details to my earlier post.
The canon only loads when it is supposed to load. How do I know this? Well the yellow light on the playfield signifying the canon mode is lit and I just started noticing that the red light above and to the right of the canon is also lit when it loads. After the canon loads the fire switch is always lit up, The DMD gives instructions on what to shoot at , Steve Richie (SR) also chimes in to fire the canon.
Then the canon swings out to about the switch 62 position and automatically fires. About the same time SR is shouting fire or Come On x 4. After the canon autofires, it finishes its path out and back to the starting position. Once it has returned SR screams "Next time use the fire button stupid!" or "You Lose(might be "snooze" it is hard to tell) You Lose."

My understanding of how the canon is supposed to work is that the canon will swing out and back for you to fire the ball. If you do not fire the ball it will swing out again and autofire the ball at which time it tells you to use the fire button next time.

Based on the symptoms displayed by my machine I believe that for some reason it is skipping the first swing out and back. Something is making the machine think it has already made the first out and back pass so it is going right to the second swing autofire mode.

I have spoken with the CS at Stern and while they have said they will work with me on this the person I spoke to didn't have any ideas on how to fix it.

Any help is appreciated.
JtL

Had the same problem, replaced the cannon opto, works perfect now.

Thanks Sk8ball,
Stern is sending out a new Opto so hopefully that will solve my problem as well.

I'm having the same problem with the cannon. What's an opto switch?

Mine did this. I just had to restart the game to get it working fine again. <shrugs>

Called JJ at game exchange he walked me through cleaning opto switch and I haven't had anymore problems.

So did you get the issue resolved? Seems to be common issue so hoping you're back in business Taylor.

A solution can be to loose the screws of the opto pcb push it in the direction of the interruptor and fix it again. It seems that the timer for interrupt the opto times out, so it will help to decrease the way to the opto.

Hope this will help.

SOS. My AC/DC Pro just started to give the following error message Cannon Eject Device malfunction. When starting the machine, the cannon will deploy and then go in and out a dozen times (sometimes it is a quarter inch away from totally returning to the ramp.) Eventually, it stops trying and reads out the error message. The ball detection microswitch checks out ok. The solenoid will repeatedly try to fire the ball as the empty cannon deploys. Any thoughts, please? Regards, Bo

Any updates on a fix? My new game played correctly a few times, now it autofires every time. And damn, Steve Ritchie keeps calling me stupid!

Fixed. The opto pcb was loose, tightened the screws and it works every time. Thanks to Av8 for suggesting this.

second this for anyone else that runs into it. My opto was dirty. Cleaned it and re-installed and all works now.

Updating a very old thread. Friend has this issue. I played with opto a bit. It activates perfectly every time but it then fires the ball after 1 second and Steve Ritchie yells and says to use the fire button. Not sure about cleaning opto. The metal travel arm runs through the opto path right away and seems to be functioning correctly. But ball fires as soon as cannon moves and sw activates

How does that make you feel when Steve says that?
You do have an option on the machine menu to adjust the "insult level" or something like that...
Perhaps if you get your feelings hurt when that happens a lot, you can make the machine less insulting.
Personally, I like mine on "heavy"...
I think it's funny...

Thx. On the small opto board are there 2 spacers ? One for each screw? Funny after messing with it he says it’s worked fine for 10 games. Plan B is cleaning opto with q tip then I can tape off opto like you did

If you need a new opto card for the cannon, you can get one here...
I think this is the same one that is on the bell.
It is about $11, plus shipping.
https://www.pinballlife.com/stern-opto-board-with-right-angle-connector.html

Had the same issue with my 'Luci', removed and cleaned the cannon opto with a QTip and alcohol and now works great!