(Topic ID: 49434)

LED lights in Bally 1978 SS game - new board required??????

By rufessor

6 years ago

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  • 78 posts
  • 28 Pinsiders participating
  • Latest reply 1 year ago by rufessor
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#1 6 years ago

Hi All-

Just acquired a Bally 1978 Playboy. I am thinking of going with LED everywhere and see kits that include a new driver board. Is this really necessary, I typically just custom order my LED's from coin taker so I can do the colors as I would like... do I really need to also change the power supply board? Seems totally not required, Coin Taker has LED's that are designed to deal with the flicker issues that were common early on. So- if I use LED's designed specifically to avoid the flicker, can I just put in new bulbs and leave the power supply/board alone?


If the answer is that I do not need to get a new board... ca you can explain why it is that the kits come with a board - I would appreciate it as a knowledge building exercise.

#10 6 years ago

Ok... glad I asked this cause its not as simple as I thought-

I will probably look at some higher power (draw) multi LED lamps for the switched LEDs. They are mostly under the playfield under inserts and since much of the light on a multi socket is distributed to the sides (if you get the right one) it should not be too bright. In fact, I have some extras. This should answer the question as to if I will need to fix the sockets with a solder mod for the switched bulbs. I will check this and post back if it works.

I believe the flicker on the LEDs in GI is probably due to the DC rectifier and a voltage dip - the No flicker LEDS probably solve this with a capacitor in there or similar ... The no flicker LEDS should solve any GI issues as the draw would be plenty I would assume.

#12 6 years ago

Well... this is the easy part... but I can tell you that replacing about 1/2 of the bulbs behind the back glass with LED from coin taker, cool white I cannot remember exactly which one but at least a generation 2 bulb... and its works fine- I need warm whites for the colors but I had about 12 coin takers left over from the last project I did a total conversion on and so I just tried it out. Of course things could be different once they are all LED but I doubt it... seems rock solid stable light.

Will continue to update with programed pulsed lights being the most interesting to try to convert without the mods to the latch circuitry. . . this is phase 0.1

#15 6 years ago

I too would be interested... how much mod would need to be done to incorporate them into the game?

#17 6 years ago

Interested- need to see what in fact it is your making but price seems right and its needed. Maybe let us know whats up or show a pic.

On same topic. Just to illustrate the difference between switched bulbs with LED replacements and standard GI/Backglass always on lights. Here is a link to a video I took last night. I replaced all the lights behind the top of the back glass with coin taker LEDs and then also replaced the "recent High Score" lights, which are switched with LEDs. And this is a "best case" scenario, as there are TWO bulbs that are in the switched circuit so the current draw is additive for both LEDs- yet the flicker is amazingly annoying. Remember, the middle art work on the backglass is standard lighting, the top row lighting behind the words PLAYBOY and the pink bunnies are Coin taker Cool White LED, and the two bulbs under the high score are also the same LED but switched... and they flash super bad.

You tube video I uploaded... link

#19 6 years ago

Agree- good price

1 month later
#31 6 years ago

With respect to the requested pics.... I can post one of my 1978 playboy. Seems like you all ready know there is an issue so if you want a pic just ask again. The Playboy has a limited # of controlled bulbs. But enough that I am not certain I want do that much soldering as it gets into removing original equipment and modding it, so let me know if you Make progress, just running a cable through a small aux board seems less intrusive and could be done with Velcro or something removable. still interested

1 month later
#33 6 years ago

Cool... still on the fence about this- Currently working on what will be a very long restore process on my play field and have probably months before I will be installing LEDs in the game. This looks OK but I am trying to figure out a way to do this without quite as much modding to the game. I wonder if it would be possible to trace these wires back to the control board and somehow put a resistor in line there? Did you look into this at all?

Just thinking that if its an easy connection you could theoretically put a resistor in series there (just remove the wire from the board connector and add a resistor and a small wire to place back in the connector... in this way the original wire would not even be cut and you could simply just desolder the resistor and place the original wire back into the control board if you ever wanted it gone.

Anyone know where these wires come from- is it in fact 1 wire/bulb coming off a control board? Seems like it should be since they are in fact controlled independently. I just have not a clue where to look!

Reason I ask, is I will be rebuilding all the connectors, so this is a 1 minute mod at that point...

#38 6 years ago

Thanks for the tip on the sound board. I noted it but didn't really think much of it. Being so old I kinda assumed it was normal. Now I can check that... in a few months or more when it starts to go back together.

As for the lamp boards, I have zero issue basically rebuilding a board from scratch with chips and a soldering iron so I have no hesitation about diving in and adding some resistors. However, if the pricing is right and its real easy- would still consider purchase of adapter. Only reason I asked was that I have not in fact begun any type of restore on this part (I am dealing with play field first as thats the worst part and if I can make it shine... the rest of the game will be fully restored- but not until then). So I just wanted to be sure that I had this correct. Since I will be rebuilding the connectors and even replacing some of the CAPs on the power supply board I figured I would ask if there was a good reason not to do the mod there.

Will keep an eye out here to see if you get a board out and the price and then decide, but for now its no rush on my part.


1 month later
#40 6 years ago

Indeed my prior post is conflicting.

I have a little bit of circuitry knowledge but not on the level that these boards require to fully understand. I am basically a beginner electronics hack, I figure out what I want to do, ask questions with usually incorrect terminology and learn as I go. What I should have said, is that I can figure it out given a little time and some help and have no problem with the mechanics of the required skills, I can solder PCB components (not production level but not overly sloppy either) I can do some basic tracing etc and identify common old school components like resistors, caps, diodes, zenner diodes etc and know what these do and how to for instance make a bridge rectifier and other common uses for these components... and I have some relevant experience in building LED lighting systems... but its all hobby level type stuff. Sorry if it sounded like a complete hack. When I said I didn't know where to look for the origin of the wires I should have said I do not have schematics and my skill level in reading them leaves MUCH to be desired so it would possibly be unclear to me where they physically resided even if I had them locked down on the schematic...

Just trying to get my head around what the actual technical challenges to this mod are... your information was very helpful and I appreciate it. Indeed it would appear that the basic path is either through the sockets or what has or is being developed and discussed here.

Here is a question then....

If I do this...
is the reason it would not work this...

If I were to disassemble the wiring harness from the light control board, and add a resistor to the end of each independently controlled light (which must be a single unique wire- correct) and then simply solder a connector onto the other end of the resistor and plug it back into the harness...

Would the LED now NOT function because of the induced voltage drop associated with this resistor? Cause although I do not know what the latch current is, perhaps you could choose a resistor that would pull that current while leaving enough voltage to power the LED... LEDs can be some what flexible with respect to input voltage so long as its above their threshold...

This (if I am not now over my head and exposing further ignorance) would be a fully reversible mod that would actually be pretty easy)

But it depends on

A) my actually understanding this (shaky at best)
B) if A is affirmative - the lost voltage being insignificant with respect to the LED operation.

#42 6 years ago


I apologize, I understand the difference between series and parallel in nomenclature, but what I had asked was why it would not work.

I think I can reason this through- the total current draw through a series circuit is the same at any point... current is basically just the number of electrons moving and we don't "use them up" anywhere....

So if you place a resistor in series its basically just acting to either drop voltage or limit current, and the LEDs all ready must have a current limiting resistor in series.... so there would be no change to the latch current seen by the board.

If you put it in series then additional current can flow... and the latch circuitry will now see enough draw to remain open and the light will not flicker. What I now am thinking about doing is shown in the following post-

Basically, simply add a resistor in series to each post of the wiring harness for the controlled lamps.

#43 6 years ago

Like this


#44 6 years ago

Where each pin is shown connecting to both the resistor and the LED in the game-

I guess if no one argues with this and since the playboy has a very limited set of controlled boards, all I would need to do is get a schematic and figure out which wire from which harness is running the controlled lamps. I might be able to trace with a continuity meter but that may or may not work.

Schematic indicates that basically all used pins on J1, J2 and J3 would need to be modded to go full LED... GI seems to come out J4 although I am unsure what J4 pin 8 labeled KEY is...

This will be a little work, but cost is negligible and I was going to re-pin these anyways... so really almost no extra time on top of that.

Ugly.. but perhaps functional and no one will see it anyways. At least its all sitting right there in front of you.

#46 6 years ago

Cool.. I think I will just mod the connectors... Since I am re-pinning anyhow this is no trouble whereas re-pinning plus dealing with sockets is 2x the work and a more permanent mod and I have no interest in dealing with the LEDs themselves. Great quote...

SORRY for the confusion, I had not THOUGHT through my proposal to put it in series... my bad... Thank god my day job does not involve circuit design (who would have guessed?!)
Simple-stoopid but I stand corrected and happy to have an easy, viable, mod to accomplish.


#49 6 years ago

I am going to try to do this in a way that does not look like a massive hack! I will post pics! Here.. but its going to be a good long while until I get to this.

#51 6 years ago

Wil post pic for sure...

I am almost over the hump on the fairly detailed restoration of a partially trashed play field, probably another month+ of work in paint (granted, this is a very very part time hobby...) Then after I get it cleared and ready to assemble I may or may not go right to this mod... but probably will do mechanical first and then.... I need to repaint the inside of the cabinet and thats easier with the play field fully stripped since I can just set it down (upside down) and not have to worry about damaging anything so its going to be a good while before I do this. At least I know the game played 100% prior and I did some board work on the displays to fix a few issues before I got really into the game so once its ready for assembly it should go quick.

1 month later
#61 5 years ago

Jumping in since it was asked- The status of my restore is that I am making progress and on the last step of the major part I "learned" again and need to wipe off a fair bit of work and start over

Although I will be putting resistors in line on the connectors its going to be months before I get to that. I have another week or more of re-do-the-work-I-JUST-did.... Seems like I will be using this thread as a reference as I asked the question but others have done this and the knowledge here is great- Thanks to those who worked this out in practice and have working LED's in controlled lamp circuits-

Great JOB!

I will post pics here when I get around to doing it the way I outlined- but its not any different really than what has been shown, just the location of the resistors.

4 years later
#78 1 year ago

SiegCraft electronics sells basically this mod... it's basically a plug and play jumper with resistors to ground for each of the controlled lamps. I ended up buying one but will not be installing it. I cannot stand the instant on and off the LED yields whereas the incandescent bulbs give you a fade in and out... so for me it was an interesting adventure but not fruitful in the end. I would actually pay 100+ for a PWM controll board... if someone wants to make that....

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