Name of game, manufacturer and year: Terminator 3, Stern, 2003

Did it ever work in your Possession?: Yes

Did You Run the Diagnostics?: Yes, although I am not sure what I am doing.

Where did the game come from?: Alberta

Have needed MODS been done?: no

Are any aftermarket boards installed?: Not that I am aware of

What was the last service you performed?: Coil repair on backbox canon

Battery Corrosion: not sure

LED or Incandescent lighting?: LED

Blown fuses: no

Smell: no

Obvious Past Work Performed: not sure

Do you have a Volt Meter?: yes

Can you solder?: yes

Location: Courtice Ontario

Hi there,
Sorry but I am brand new to the hobby and looking to troubelshoot and fix some issues I am having. I got this game few weeks ago and it seems to me (inexperienced) to be in good shape and works well most of the time.
A few nights ago after much playing with no problems, the game started shooting balls after multi-ball mode was activated forever and ever, jackpot after jackpot. Even if we let all the balls do down, they would just keep shooting up.
I have done some research and saw someone else with almost the same issue on a different game and the issue was cased by the through switches. In his case, one of the pins had broken off entirely and the fix was obvious. In my case nothing looks broken and my diagnostics, seems to register when I move balls on and off the switches.

The second and more rare (related maybe) issue I am having, is sometimes after a ball goes down, the game never shoots the next ball over to the launcher and the game loses another turn. In other words, after ball 1 is done, it just also downs ball 2 and starts you on ball 3 but ball 2 never even entered the playing area.

Anyway, sorry if this is a bit confusing but I wanted to get some advice before I start ordering new switches which may end up being a waste of my time.
Any feedback is greatly appreciated as I expect I will have more issues down the line and I want to communicate as effectively as possible on these forums.

My picture of the switches are attached.

20200713_013712 (resized).jpg

Thank you for replying. Just to make sure I understand what an opto board is, you are referring to the two outside switches that the balls roll over when entering the chamber? If yes, I will remove them both and redo the soldering. Should I reflow the resistors solder at the same time? They seem to attach from pin1 to pin3 on each opto board.
Since the issue is intermittent, would it make sense to replace anything while I'm doing this or just reflow and then test test test?

That's awesome, I'm very glad I asked. For this price, I will look for a Canadian store that I could order these boards from and just replace. I really appreciate your advice and I will report back afterwards.

While I wait for my parts, I wanted to document some more about this issue for anyone else who may have the same kind of problem.

1. The issue seems to only occur after the table has been on and played for a few hours. After the issue starts to occur, it happens all the time.

2. The game seems to NOT be in multiball mode since it allows me to play and earn towards a multiball bonus.
3. Multiball is only supposed to shoot 3 balls into the play field, but when this issue occurs, all 4 balls go into play continuously. Even if I don't do anything and allow all the balls to drain, the game keeps shooting them out indefinitely and I have to turn the machine off.
4. Even after turning the machine off then back on, the problem will still occur. I need to let the machine "cool down" before it will work properly again.

Once my new opto boards get here and I replace them, I will post back the results.
Thank you

So to update. The optoboards arrived a while ago and I have installed them. Need to give this a good test run to see if they made any difference. I'll keep the thread updated.

Worked the machine last night for about 5 hours and the issue did NOT reoccur yet. Going to give it another go on Saturday before thinking it's fixed.

Ran the table for over 7 hours last night and no issues. I'm thinking the issue is now solved. Not only did the table NOT spit out balls forever in multiball mode, but it never skipped a ball on anyone (meaning going from ball1 to ball3 as if ball2 was drained).

Before I close this thread, is anyone able to explain to me logically, how replacing the opto boards fixed this issue? I would like to have an understansing so I can learn and use the knowledge for the next problem I encounter.

Thank you!

This is all great info. Thank you all for your help and input.