(Topic ID: 6050)

Eddy board adjustment

By Marten

11 years ago


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  • 36 posts
  • 10 Pinsiders participating
  • Latest reply 7 years ago by neurokinetik
  • Topic is favorited by 12 Pinsiders

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#1 11 years ago

Hi everybody,
I have a Roadshow which has three eddyboards (and sensors).
Two of them are ok, but one, for the bulldozer hit, keeps needing adjusting.
It's almost a daily thing. Sometimes the LED stays on all the time and sometimes it stays off when
I move a pinball over the sensor. I've already tried switching the eddyboards around but
the problem stays with the bulldozer. I've seen that you can buy a replacement board
that adjusts automatically but before I spend the money I'd like to see if I can fix it myself.
Where do I start? Any advice is welcome!

Thanks!

#2 11 years ago

Those Eddy boards do go bad over time and since you have tried
adjusting it and keeps doing the same thing it would be a good
idea to go ahead and replace it.

#3 11 years ago

"Eddy" boards??? What exactly is "Eddy"? I don't know that's why I'm asking...

#4 11 years ago

Thanks Pinmike,
I'm not sure if the problem is only with the one board though. I moved the board that was
at the bulldozer to an other sensor and there it is working with no problems and the
one that was good over there is now having problems. Do the sensors ever go bad or is
there maybe higher vibration at the bulldozer that knocks them out of adjustment?
Could replacing the potmeter on the board fix it?

#5 11 years ago

Jrrdw,
Eddyboards are little circuit boards used in combination with sensors that sit just underneath the playfield that can sense when a pinball is close to them. They are used instead of conventional
switches that the ball has to push down to close it. I guess it is a similar system to the ones you see
at traffic lights where they put a loop in the asphalt to know there is a car waiting to cross the
intersection. They sense when there is a metal object close like a car or a pinball.

#6 11 years ago

The potmeter could have gone bad and its worth a shot to
change it if you dont plan on buying a new board.

#7 11 years ago

Ah, thanks for explaining that. It's a wonder they don't pick up on all the electromagnetism under the play field.

#8 11 years ago

It's not that I won't buy a new board but I like fixing things and if I can
do that by replacing a 50 cent part then that sounds cheaper and more fun than buying
a $60,- replacement board. I figure that if I mess it up I can just move a board from a not
so critical position while I wait for the new one.
Should I also replace the capacitors? I heard that they can go bad over time too. After all this is
a 17 year old game by now.

#9 11 years ago
Quoted from Marten:

Should I also replace the capacitors?

When they go bad you will see it. They will 'cook' and the top will open up and look like corrosion is growing, the plastic will receed from the top and they swell up.

#10 11 years ago
Quoted from jrrdw:

When they go bad you will see it. They will 'cook' and the top will open up and look like corrosion is growing, the plastic will receed from the top and they swell up.

Good point

#11 11 years ago

The adjustment middle part in the pot becomes weak I believe, and will start to move with vibration. I don't know if you can find them, but that would be the thing to replace in my opinion, however I'm not sure if I'm correct in this 100%. The left hokus pokus on my ToM needs re-adjusting about every 3-4 months, so nothing I'm concered with now, but if it became even a weekly thing, I'll review my options.

Do you notice any visible change in the adjustment once it stops working, as is, where you previously set it, it apears it has moved? If so, I might try setting it, and gluing it there. You could always heat that up later to remove, and if it doesn't work, it's not like you're hacking anything that won't be replaced anyway.

#12 11 years ago

Ah, thanks for explaining that to me jrrdw.
I haven't seen any of that on the capacitors.
I'm going to look for a replacement potmeter next week and break out
the solderingstation. Hope I still know how to solder. It's been more than two years.
Will let you all know how it went.
Thanks!

#13 11 years ago
Quoted from Marten:

Should I also replace the capacitors? I heard that they can go bad over time too. After all this is
a 17 year old game by now.

C3 should be removed regardless of the condition. Read this:

http://www.pinbits.com/index.php?main_page=product_info&cPath=13_4&products_id=188

#14 11 years ago

@atomicboy:
I tried looking whether the screw in the potmeter moved but haven't been able to see that.
The adjustments needed are tiny. I will try your gluing trick first.
For me the adjustments are almost everyday and sometimes twice.
It's just getting annoying. Removing the lockdownbar, sliding the glass out, removing the balls,
lifting the playfield, adjusting the potmeter, testing with a pinball and then putting everything back.

#15 11 years ago

Heres some info:Adjusting Eddy Sensor Boards.
Often eddy sensors can go out of adjustment and become less sensitive. This can cause the eddy sensor to not activate when a ball passes above it on the playfield. To adjust an eddy sensor do this:

* On the under the playfield eddy sensor control board, turn the potentiometer counter-clockwise until the LED just turns on.
* Now turn the potentiometer back clockwise until the LED just turns off.

That is all that is required to adjust the STNG/ToM/RS eddy sensor. To test the sensor, put the game into WPC diagnostic's first switch test. Then move a pinball over the playfield area where the eddy sensor is located. The switch should activate on display. Also from the bottom of the playfield, the eddy board LED should go ON as a ball passes in front of the eddy board's senssor (this can be seen anytime, the game does not need to be in switch test.)

Different R1/C1 Eddy Sensor Values (Fine Tuning).
Because the ball sensors are different on some games, the value for R1 on the Eddy sensor boards can be different. For example, on Star Trek Next Generation and (two of the eddys on) Theatre of Magic), R1 is 4.7k ohms (these games uses the small ball sensor). But on roadshow and the ToM trunk, which uses a much larger ball sensor, R1 is 2k ohms. So if you switch an Eddy board between these games, the Eddy R1 resistor may need to be changed to the correct value.

The purpose of the R1 resistor is to make the adjustment pot "centered" for the particular ball sensor. For example, if you use a 2k ohm R1 eddy board in STNG, the adjustment pot will be turned almost all the way up (with very little adjustment range). It still works most of the time, just the adjustment range is not centered.

With this in mind, I once had a roadshow where I could not get the eddy board's LED to turn off, no matter where the adjustment pot was moved. Normally roadshow uses 2k ohm R1 resistors for all three eddy boards - but in this case I had to replace the R1 resistor with a jumper wire (0 ohms). This put the adjustment pot about dead center, and the eddy boards worked great (with the 2k ohm R1 resistor, the eddy boards would not adjust, and hence would not work.) Another trick is to change the C1 cap to 3300pF, which widens the field of the eddy sensor a bit

#16 11 years ago

hmm, good read.

#17 11 years ago

Ah, interesting.
A lot of new info.
My potmeters are pretty much centered when adjusted right so I don't think it's the
resistors with me.
I don't think I have one of those "advanced controllers' installed but will take a closer look tomorrow.
If I don't, should I still remove C3?
Thanks!

P.S. have to run. I have to go to the airport in less than an hour. Flying home after 11 days away
for work. Missed playing pinball.

#18 11 years ago

Also, have you checked that the connector is okay on the board that's not working well? On my TZ (I assume these are the same kind of sensors as TZ uses to detect the powerball), I've never had to adjust them, but the connectors are really dodgy, and i've had to reseat them numerous times.

#19 11 years ago
Quoted from DrAzzy:

? On my TZ (I assume these are the same kind of sensors as TZ

No they are not the same boards as TZ, TZ has proximity sensor board.There is only
one eddy sensor in TZ and its in the ball trough, but it's a different design than the STNG/ToM/RS eddy sensor.

#20 11 years ago
Quoted from pinmike:

Heres some info:Adjusting Eddy Sensor Boards.
Often eddy sensors can go out of adjustment and become less sensitive. This can cause the eddy sensor to not activate when a ball passes above it on the playfield. To adjust an eddy sensor do this:

* On the under the playfield eddy sensor control board, turn the potentiometer counter-clockwise until the LED just turns on.
* Now turn the potentiometer back clockwise until the LED just turns off.

That is all that is required to adjust the STNG/ToM/RS eddy sensor. To test the sensor, put the game into WPC diagnostic's first switch test. Then move a pinball over the playfield area where the eddy sensor is located. The switch should activate on display. Also from the bottom of the playfield, the eddy board LED should go ON as a ball passes in front of the eddy board's senssor (this can be seen anytime, the game does not need to be in switch test.)

Different R1/C1 Eddy Sensor Values (Fine Tuning).
Because the ball sensors are different on some games, the value for R1 on the Eddy sensor boards can be different. For example, on Star Trek Next Generation and (two of the eddys on) Theatre of Magic), R1 is 4.7k ohms (these games uses the small ball sensor). But on roadshow and the ToM trunk, which uses a much larger ball sensor, R1 is 2k ohms. So if you switch an Eddy board between these games, the Eddy R1 resistor may need to be changed to the correct value.

The purpose of the R1 resistor is to make the adjustment pot "centered" for the particular ball sensor. For example, if you use a 2k ohm R1 eddy board in STNG, the adjustment pot will be turned almost all the way up (with very little adjustment range). It still works most of the time, just the adjustment range is not centered.

With this in mind, I once had a roadshow where I could not get the eddy board's LED to turn off, no matter where the adjustment pot was moved. Normally roadshow uses 2k ohm R1 resistors for all three eddy boards - but in this case I had to replace the R1 resistor with a jumper wire (0 ohms). This put the adjustment pot about dead center, and the eddy boards worked great (with the 2k ohm R1 resistor, the eddy boards would not adjust, and hence would not work.) Another trick is to change the C1 cap to 3300pF, which widens the field of the eddy sensor a bit

Does this apply to the trunk in TOM? My trunk does not register hits every time? Is this an eddy sensor and do I follow this advice? Thanks.

#21 11 years ago
Quoted from Shapeshifter:

Does this apply to the trunk in TOM? My trunk does not register hits every time? Is this an eddy sensor and do I follow this advice? Thanks.

Yes,This info also applies to TOM and you might want to check this out if you plan on changing the trunk board pretty cool design and it adjusts itself http://pinbits.com/index.php?main_page=product_info&cPath=13_33&products_id=375

#22 11 years ago

Thanks pinmike, that looks excellent

#23 11 years ago

The machine was cold, adjusted the potmeter and glued it in place.
Worked fine for half an hour of play and then it started to register rapid hits on the bulldozer.
Great for scoring but not quite what I was looking for. A little bit later the sensor was closed constantly.
Didn't touch anything and turned the machine off. After half an hour tried it again and it was fine.
But the process repeated itself.
Seems to me now that it is not the vibration moving the potmeter but probably heat build up
causing trouble.
But why does it only have an effect on the bulldozer hit?
HELP!

Post edited by Apekop : typo

#24 11 years ago

There must be a component on the board this is shorting out when it heats up, which makes me think it is an IC. My knowledge base ends there. Try checking RGP for anything similar to your issues. Is a resistor slowly going open...?

Quoted from Shapeshifter:

change the C1 cap to 3300pF, which widens the field of the eddy sensor a bit

This "sounds" like it might assist, but you may want to spring for the pinbits replacement at this point. I hate recommending a cop out like that, but I don't know what else to tell you, unless someone else has anything to add.

#25 11 years ago

Thanks Atomicboy,

I've already been looking at that board but it was out of stock a few days ago.
Maybe I'll try the shotgun approach and replace everything on the board.
Only the IC may be a little bit harder to find.
It couldn't be the sensor that is going bad right? It's only a loop after all.
Or a connector?

#26 11 years ago
Quoted from Marten:

It couldn't be the sensor that is going bad right?

Sensors do go bad.

#27 11 years ago
Quoted from pinmike:

Sensors do go bad.

Hmmm, maybe that's where I should direct my attention first.
Thanks.

#28 11 years ago

As for pinbits, they seldom go out of stock for anything. The website states this, but when you call, they usually have them, just haven't updated the site. They are a "mom and pop" shop so to speak, so their system gets updated when they get around to it.

#29 11 years ago

I've noticed that the sensor gets more and more sensitive as the game heats up and ends up
detecting a ball all the time even if it isn't there. So I adjusted the potmeter in a way that, when cold, it would barely sense the ball. Now during play it still gets more sensitive put doesn't lock on
any more. Potmeter lightly glued into place for good measure. Hope this solution holds.

The connectors also look like they have been reseated many times so I may just replace them all
for good molex ones instead of the old IDC's.

Thanks everyone for your help and I hope this is the end of it!

P.S. During testing the hold circuit on one of the flippers failed. A wire had fallen of the coil.
Does it ever end? Good thing I like tinkering.

1 year later
#30 9 years ago

So today I finally got sick of adjusting the potmeter for a year and replaced it.
It fixed the problem but the board stopped registering hits during the 2nd game I played.
Weird because the led came on when I held a ball over the sensor.
Turned out to be a wire being loose on the IDC connector. Easy fix.
Thanks again for the help and sorry for resurrecting this year old thread.

1 year later
#31 8 years ago

would anyone be willing to post some pictures of what you are adjusting and where its located? im a total n00b and am just totally lost on if my game has all these same control boards. my road show dozer sensor hasnt registered hits since i got it. i pulled up the play field but was totally lost. im slightly nervous to adjust stuff with power on, but im guessing thats necessary. thanks for any help.

#32 8 years ago
Quoted from tpike:

would anyone be willing to post some pictures of what you are adjusting and where its located?

It will be on the underside of the playfield around where the dozer is (apologies but I dont have a RS to take pictures for you). Look for a board like below. In the middle to the left of the red LED there is a black box with what looks like a screw head. That is what everyone is talking about adjusting. Theatre of Magic uses the same type of sensor. I turn it all the way until it doesnt turn anymore. The red LED will be off. You the turn it back slowly and once the LED comes on you want to stop. Your dozer should register now! If not it's possible you have a bad sensor and it needs replaced. Best to purchase the sensor from Pinbits as they're self calibrating thus you never need to adjust them!
http://www.pinbits.com/index.php?main_page=index&cPath=13_25
wmseddy1.jpg

#33 8 years ago

Y'all are awesome! Dozer works! Kids are cheering...ok it's really me cheering :p

#34 8 years ago
Quoted from tpike:

Y'all are awesome! Dozer works! Kids are cheering...ok it's really me cheering :p

Good to hear. Now these sensors can go in and out regularly so don't be surprised if you're adjusting it again!! One thing you can do is take some locktite or even nail polish and put a dab on that screw-head once you have it calibrated. By doing this it will keep the screw-head in place and limit the number of times you will need to re calibrate it!

2 months later
#35 7 years ago

I know this is a relatively old thread but wondering if someone could identify the IC used on the Eddy Sensor board, the williams manual does not list a specific IC.

#36 7 years ago
Quoted from Atomicboy:

Do you notice any visible change in the adjustment once it stops working, as is, where you previously set it, it apears it has moved? If so, I might try setting it, and gluing it there.

Or you could even replace the pot with a fixed value resistor, once you have it set where it works consistently.

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