Hey All,

Not to proudly display how little I know about electronics to everyone here, but if it's shielding we need, can we use the copper shielding tape used in electric guitar wiring cavities?

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Nope....different kind of shielding needed for magnets.....

Matt
M&M Creations

I did have this same type of problem with my Flash game. Right after putting in the NMP board it was working fine, and the next night the pop bumper next to it was resetting the 3-bank pop bumper every time the pop bumper fired. My problem was one of the magnets had come off the drop target and stuck to the metal of the drop assembly. Once I fixed that, it all worked great.

Thanks for the update. Glad you fixed it.

I am getting a reset on the 3 bank every time I hit the lower pop bumper now in my Flash game. All magnets are in the proper place. The 3 bank drops work fine as long as you don't hit the lower pop bumper.

You may require shielding......

The targets and pop bumper are similar layout as Gorgar.

Try the shield and please let us know if that fixes it.

Yeah, I'd be interested to know. It didn't work for me on my Gorgar, but I've still left it for the time being as it's still better than the horse shoe. For me I found that the pop bumper would only trigger the closest target. I could hit it as long as the other 2 weren't down and the bank wouldn't reset. After physically removing the bank from the playfield and testing the bank clamped down to a 2x4 the issue didn't arise. I even double layered shielding over that reed switch to no avail. I'll be trying to replace the pop bumper coil next to see if that helps at all. If not, I might try a different shielding material...

In your case, I think doubling the thickness wasn't the answer, I think the 4" strip was only an 1" wide and likely needed to be doubled to 2" wide...the EM field isn't strong enough to permeate through the shield material - but it can pass around....that would be the next step...

Matt

Matt

This is my fix. It is a piece of soup can. I did bend the edges to make it less sharp and wrapped in duct tape. Basically, a rectangle. It has been working flawlessly for about the last 2 weeks.

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I suggested trying a plain old steel panel but yeah it's probably hit and miss as suggested. Change the dimensions of the plate or the exact position/distance between the sensors and the pop coil, or make the plate a little curved or basically flat, might not work 100%. Whereas the mumetal sounds sure-fire.

My god - I can't believe it, it finally works! I just did the same thing to mine. Finally I can put some real stock in the scores I get. Thanks for the tip!

Hey gang, I just found this thread and I’ve noticed that my GAR target would reset with the bumper hit from time to time.

I think I’ve even seen my GOR target (or that area) trigger a random tilt on my Gorgar.

Is the suggestion to add a 2x4” piece of MuMetal to the drops? That’s what I’ve gathered from the thread. How are you cutting it? What kind of double sided tape are you using?

Thank you!

It’s not necessary to cover the entire board – just cover the sensors. I used double sided foam tape but covered the edges with electrical tape so they don’t cut into any wires. You can cut it with a good pair of scissors.
Be sure to use:
ebay.com link: itm

Others have used some different stuff that didn’t work as well.

Thanks for the response! I did use your link to purchase a sheet. The ask about the size was due to one of the posts mentioning it didn’t work for him and there was a suggestion that the strip wasn’t wide enough and possibly the magnetic field had gotten around the metal…

I’ll wrap the sheet in duct tape to cover the edges and preven anything touching the metal to avoid shorts…

I can’t wait to see if this works!

Thanks again

I wouldn't wrap the sheet in duct tape if you can avoid it. Using thin 3M foam tape is best for something like this:
https://www.amazon.com/VHB-Adhesive-5952-Automotive-Industrial/dp/B00MAT2WZU

Pretty low risk of issues. I only used duct tape because I also added on a flattened aluminum can which made the board stick out quite a bit as it wasn't perfectly flat and had sharp edges.

FWIW - I've heard of more issues on people who have done playfield swaps (myself included). Still some original setups have had an issue too. In my case I had a 1 inch strip and it wasn't enough. If you start with a 2 inch one, you're probably going to just fine.

I received the metal today and was surprised to see it was so thin. I assumed it was going to be thicker (I guess size doesn't matter!). I can't wait to try it.

btw I figured wrapping with duct tape would avoid sharp edges (though I doubt this stuff would hurt anyone) and to avoid any conductive contact. Also, I figured it adds more insulation.

It's interesting you mentioned a playfield swap. I did get another playfield which was populated that was in better shape than my original, however it had its own issues. I did rebuild the drop targets, replaced the coils, added new boards for the magnetic boards (if it means anything!)

Thanks again,

-Sal

Oh, you should be fine if it's original. I think most issues were on Mirco reproduction ones which mine is. I just ended up making the foam tape slightly longer on each side as to not expose a sharp edge. It didn't stick out enough for me or get too close to my wires to cause a concern. The soup can on the other hand...lol

In some games (Gorgar and Flash) the pop bumper may cause interference with the sensors causing a false connection on the sensors. An easy fix for this is to shield the sensors from the pop bumper coil. Ultraperm 80, (AKA MuMetal) is a perfect shield for this application. A small piece (4” x 1”) is all that’s needed. Also you need to protect the bottom edge of the metal so it doesn’t cut the wires.

I have pre-made shields for this purpose made from Ultraperm 80. The shields have a protective rubber edging on the bottom to protect the wiring. I’ve also attached 3M VHB (very high bond) double stick tape. Easy install – just peel and stick to the sensors.

Price is $7.50 plus shipping. Or $5.00 with purchase of new sensors.

Contact me at [email protected]

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Well...I thought I was in the clear. Spoke too soon. Guess I just kept testing the order of drops in a way that made me think I fixed it.

Here's what I'm getting - Every time I hit the "R" it resets the whole bank. Wiring looks good to me...

Here's a video...which YouTube annoyingly puts in "Short" form. The angle isn't great, but hopefully you can get the idea. Kinda hard to test in-game stuff. I'm using a small magnet and approaching the leaf switches for each letter.

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The side facing the camera should be facing the targets when installed. The shielding should be on the other side – facing out. I think the shielding is shorting the solder connections.

Remove the shielding and run your test again. If that fixes the reset problem, then install the board and install the shield on the outside.

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Removed the shield and tried again. Now each of them will score, but nothing triggers a reset when all targets are hit...think the shorting killed a diode? I think you're right in that the shield was shorting something. When I went to remove the 3m tape it was very thin and fell apart as I was peeling it off from adding and removing it so many times.

I wonder if a two layer PCB tinned would be enough shielding? Add score mark to snap off the shield, matching drill holes and small stand offs? If its not ferromagnetic to block the issue then you can tape across the shield board and use the standoff hardware to help hold it in place.

These original WMS drop targets suck so bad. I want to use these in a Gorgar my dad has with flaky drops.

Sparksterz:

Keep in mind that all targets must be down to trigger the reset – therefore all three sensors must be closed to complete the reset circuit. You need three magnets to hold the sensors closed at the same time.

It could be an open diode. Diode D0 is the one for the series. If that doesn’t fix it contact me at [email protected] and I’ll send you a replacement.

Barakandl:

It doesn’t take much shielding – actually only about 10% of the Gorgar games require any shielding at all.

I’ve found the MuMetal to be the best material. It can simply be applied to the sensors with VHB double stick tape. (same tape they use for auto trim).

Contact me and I’ll take care of your dad’s flaky drops once and for all.

oh my god - of course...I sometimes forget the era of machine I'm working on and inherrently assume its ability to track the state in memory. Of course it's the presence of the magnet on all 3 that trigger it to be aware. Thanks for pointing out what'd normally be obvious to anyone working on machines of this era lol.

Disco Fever is the only game of that era that I know of that doesn't use the series switches. The MPU knows when all targets are down.

Just to add my experience to this thread, I did a drop conversion on my firepower and the closest targets to the pop bumpers are being triggered by pops. 2/3/4 trigger every time the adjacent pop goes off.

I reached out to Matt, hopefully I'll get the shields soon. Meanwhile, I'm loving the drop target life!

Edit: the shields work great! Problem solved. Now to roll over this score to the 7th digit!

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