Never heard that one before.

During the DE days they would only be selling to operators, not 'consumers'.

Me either.

That's a new one.

There were a few corrections and updates in service bulletins that weren't included in the original game manuals, but that's about it.

If a manufacturer didn't want someone to fix things, they wouldn't have released the schematics in the first place.

New one on me too. Sounds like the pinball guy is BSing you. If he does think like this, Then he doesn't know what he is doing.

I've used DE schematics quite a bit, and never encountered any particularly meaningful errors, for what that's worth.

I'd like to see examples pointed out that a service bulletin didn't address later. I've seen incorrect wire colors on EM schematics, but I heard that was normal because at times manufacturers would use up whatever wire was laying around.

I've never had one issue that I can remember with a DE schematic. The operator probably has run across problems in the schematics, but saying that it was done deliberately is quite a stretch.

Pure BS.

FACT: If the operators could not easily service those games, they would never buy another game from DE.

I think what he may be referring to is the rumored old practice of intentionally putting in a mistake of some kind (usually, but not always harmless) into a schematic or other printed matter. For instance, Thomas Bros was said to have done this in their map books to try and stop the bootlegging that was occurring . If unauthorized copies were made/sold the publisher or owner of the material could come after whoever was making the copies. If you were claiming this material was your own work, no way their "mistake" would be included.

A possible example (or just a story); my brother and I re-cap'd and re-wired the caps on a vintage Ampeg amp as per the factory schematic. Didn't work. Nothing bad happened, it just didn't work. I called the Ampeg guru--"Oh, yeah--the schematic is wrong on that wire--do it like this..." His way worked perfectly. A mistake--who knows what kind.

Every schematic of modern pinball will have a mistake or two, that's normal for something of that complexity.

But if DE put the wrong schematics in their manuals so operators could not fix them, their games would have been piled to the roof at the distributors.

Like I said, the story is total BS.

As with most conspiracy theories, complete BS.

I heard that too.

Hmm. Sounds like he's trying to use that Jedi mind trick on you, so that you'll always have to go to him, instead of trying to figure it out yourself.

New one to me. Lazy and/or unskilled document-manual writers? Yeah, I believe that. Decent document-manual writers and a missing process to "check-review-correct" others work? Yeah, I would buy into that one too..a result of cost cutting and understaffing in many companies...then and now! Not sure I believe in intentional "sabotage" practices though...nah.

I have yet to experience this in DE board work. Schematics all match up and make sense, so I'd consider this misinformation. Actually, I'll go further and say that DE manuals did a better job with their schematics. They're easier to work with than the Williams/Bally IMO. I also like the block layout they created with zones on the MPU.

I'm not "The Pinball Guy" but I do live in Omaha. I could help with some of the issues you have.
Although the sound/humming problems you are having may not have a clear, easy answer.
P.S. I am only full of BS half the time

Either a good urban legend, or a pretty tricky way to spot a fake.

Poor grounding is the biggest issue I've experienced on DE games. Sometimes it is as stupid as tightening the screws on the audio board. That, and digital ground isolation in the actual design isn't the greatest, but then again these were meant to be operated in noisy areas.

There's an entire thread on this somewhere in the Data East section but using nylon washers when mounting the sound board - thereby isolating those contacts from the backbox ground plane - is what many have found to be effective in greatly reducing the hum.

Curious who the "pinball guy" might be. I've met a ton of pinball guys in omaha, but not THE pinball guy

I've done this on my Star Trek. It helped quite a bit, however, there still is a slight buzzing sound, but nothing bad. I think it's worth doing.

I have a feeling if you happen to bump into him, he'll be sure to tell you he is THE pinball guy...

Sounds like you need to find Another Pinball Guy.

I noticed an error on a system 11 schematic the other day.

On my noisy DE Jurassic Park, I placed nylon washers under the screw heads on the sound board. This effectively floats ground from the backbox ground plate. Note: there is no trace material on the backside of the soundboard under these screws or inside the mounting thruholes. Others have noted variable success rates with this approach.

There was a substantial reduction in the hum (60% better, by ear ). I further noticed this effect was most prominent (possibly limited to) the lower left mounting screw, near where the connectors terminate. When I jump backplate ground to the trace under that isolated screw head, HUM returns to 100%. No change @ the other screws.

I've resigned trying to diagnose further. I'll just live with it as a Data East thing.

Elsewhere, others have report replacing the stock backbox speakers with higher quality units had a noticeable effect. I'm not willing to make the investment to try this out as I doubt the claims, unless there is some built-in filtering at the speakers themselves - doubtful. 60Hz hum will affect any speaker.

Good luck. Report back your progress.

Maybe this guy. http://www.thejukeboxguy.com/

But aren't the operators....the consumers?

Good question, my answer would be "no". Is a rental car company the consumer? No, the person renting the car is the consumer. I would say the operator is the middleman.

Malicious intent? Uh, most likely... DE just made a mistake. Screwed up. Occam's Razor, y'all.

No, he's talking out his ass. DE schematics are 99% accurate... just like all other pinball manufaturers.

Mylstar must have had a couple of schematic errors in M*A*C*H*3, eh?

i have no knowledge of this except there was post a few months ago that rocky and Bullwinkle sound boards schematic did not match boards.i met this guy a year ago and he does have extensive knowledge to fix games.

Schematics have errors. But not intentional like this guy is suggesting. From time to time, I've found where a MFG included the wrong schematic in a manual due to a generation change in boards - but that's very uncommon.

A friend of mine sent me a text with this photo. Asked me if he was legit. I told him to stay away based on what I read on this post. It's funny how many guys think they're experts....most of whom I wouldn't trust to flush a toilet properly.

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