1N4004 through 1N4007. Any diode in that range is what you need.

Sounds like you have a switch matrix issue.

Did this just start ? If so check what you did last.

Common switch martix issue is a switch wired wrong, diode on backwards. Easy to check the switches in your game, start with the row and column the left slingshot is on, then all the others.

Every switch into your game is wired the same. Black end of the diode to a lug with the white wire, silver band end of the diode to a lug, green wire to a lug. They should all be the same, easy to spot the different one. Look for any that have wires and diode mashed together.

LTG : )

Odds of the diode being bad are slim. The odds it's wired incorrectly are MUCH higher. Yes. You said it was wired wrong and that you re-wired it. Have you considered that you re-wired it incorrectly?

Post an image of how it is currently wired since I assume you didn't record how it was originally wired.

There are many ways to wire up switches in the switch matrix but only a few ways to wire it up correctly.

You should be able to test the diode in circuit. You shouldn't have a problem with a standard leaf switch (which is what slingshots are normally). The microswitch requires special manipulation.

Thanks. I cannot see the switch lugs nor the diode and its orientation. It needs to be a wider angle view. I just cannot see enough in that image.

The left outlane switch is incorrectly wired. It is unlikely that it spontaneously wired itself incorrectly.

Lol! Very true Victor. White wire is soldered to the banded side of the diode. Should be soldered to the non banded side.
Easy fix but can be a tough investigation.

Doesn't matter. They do the same thing. Look at their traces.

Move the white wire from the silver banded end of the diode to the black end of the diode. As DumbAss pointed out.

LTG : )

Not always if you pay attention to Williams wiring pattern. Solid color on the wires, not stripes to quick check.

Every switch in the game is wired the same. White wire to black end of diode to a lug. Green wire to a lug. Silver band end of diode to a lug.

Once you study it a bit, looking over the switches top of playfield and underside of playfield, only takes a few minutes to quick check.

And look for any lugs squished together, or if you changed a switch or target recently. Start there.

Get that down and you can save a lot of time and trouble.

LTG : )

The following cites the above as the basis for comment but the comment is not directed to HEP.

The investigation is the part that requires work. Often from the person asking for the help. Quite a few times, the person wants a quick and easy solution or suggestion to fix their problem. That is rarely the actual outcome.

I was trained in a profession that taught the approach to an investigation is made up of two important things.

1. History
2. Examination

The history requires not only asking questions but getting answers to them. There's plenty of examples of questions being asked in response to requests for help that go unanswered. An unanswered question hampers the person attempting to provide the help since there is missing information to make an assessment.

Examination often requires visual inspection. Since the help is being provided remotely, what is visible to the person asking for help is not visible to the person providing the help. This is the reason I always ask for images. There are numerous examples of "I checked the wiring and it's correct" when, in fact, the wiring is incorrect. There are also numerous examples of "no evidence of corrosion" when, in fact, there is evidence of light (sometimes heavy) corrosion.

Agree with the above advice. Fix the wiring (as suggested) and try the tests again. If the tests still result in multiple switch closures for a single switch then post some more images of the wiring. Particularly wiring that may have been recently changed. These games do not leave the factory wired incorrectly. They end up being wired incorrectly when someone changes something.

No idea.

Search for a 1N4001, or 1N4004, or 1N4007.

1N4001 is usually used, I like the other two. Higher voltage and if you accidentally put on a coil, they work there too.

LTG : )

The factory used a 1N4004 general purpose rectifier diode. It is rated at 400V and 1A. You can use a 1N4007 (1000V) as well. These are readily available from many electronics merchants - Marco is not the only place that carries these.

https://www.marcospecialties.com/pinball-parts/1N4004

LTG : )

Get a few extra while your at it so you can keep some on hand.

Have you looked over all the switches yet for any wired wrong, diode on backwards ?

LTG : )

Always look for a single cause that explains all things you are seeing. The more you change (re-wire) the more locations for possible error. Always change one thing at a time and RE-TEST. I would advise clearly documenting the history (changes) that were made and showing images of the wiring of the changes. Since the reader of this thread cannot see what you see, posting an image is important as a means of second opinion.

That 16-opto board has had some prior work done to it. If you suspect the board then disconnect J5 from the board and re-run your switch test. Ignore the error reported about checking fuses. The error is reported because you disconnected the trough optos and the software looks for that. Just enter switch edge tests and report your findings for the problematic switches.

• Re-seat the 4 position 34-pin ribbon cable at all points. Be sure you have not inserted it off-by-one in either X or Y axis.
• Make sure you have J116/J117/J118 power to the DMC board.

So did that fix the display issue? "DMD and power back on" does not specify if the display issue has been fixed. It could mean that you have power allowing the random dots to be displayed. It's not specific enough.

If the display is now functioning correctly then what is/are the issue(s) that still need resolving? I can't speak for others but since it takes a week between posts I have forgotten what your current issues are since a lot can change (that you may or may not have documented) in the space of a week's worth of time.

Post images of the wiring if you are unsure. More eyes will allow more assessment.

Sorry. I don't know the rules for this game. When I do diagnosis, I primarily determine results from diagnostic tests not game play features.