Yes.

LTG : )

I've seen it on games. No idea the method.

Hopefully someone that has done it can help out.

LTG : )

Someone did this on a Flintstones I had(before I bought it). From what I saw, they literally just cut the header from the opto wiring harness and soldered the switch leads to a leaf switch. It was kinda screwy because they used 2 switches on one side, one for the lane switch and one for the regular flipper, as I recall. But, yeah, just throw a leaf switch in there. Might need a diode, too.

Double stack switches are needed to control upper flippers since they are separate. The fliptronics board itself handles flipper logic like lane changes.

I don't think there are diodes on the fliptronics flipper boards, but I haven't replaced on for awhile.

Lane changes, entering letters for high score.

LTG : )

No, I don't think so. There are 2 optos on the flipper board, one for upper and lower flippers, there isn't a separate logic switch, so it must be controlled at the main fliptronics board.

However there are resistors...

This pic is from Judge Dredd manual, with 2 flippers on the right.

pasted_image (resized).png

Closed fliptronics switches are passed to the mpu board for processing from the fliptronics board. The resistors are likely there for the opto receivers and can be left off the leaf switches.

Possible, yes.

However, pretty much nobody does this.

So I doubt that anyone has a guide for you.

EDIT: Dumbass looked at this deeper than I did! A lot of switch circuits have voltage across the switch on the switch sensor wire. This circuit isn't like this!

So, initially when I posted here, I was connecting ground to the switch line. That won't do much here. I'm rewriting this post to suggest connecting +12V.

I personally would stick a piece of solder in the holes of the connector for the left side flipper switch. I like .031 diameter solder because it allows me to rapidly connect to the .100 connectors.

I'd be looking for the grey-yellow (+12V), and one of these:

Black-Green
Black-Violet
Black-Blue
Black-Grey

(Check your book to find out what wires are connected to Fliptronics board J905... I got these colors from a Fishtales book, different pinballs used different wire colors...)

There is some weirdness with the 12V power wiring. On the left flipper button's contacts, there are grey-yellow wires, to pins 6 and 7. One of these is the source of +12V for both opto flipper button boards left, and right. It should be connected to pin 6, but on the board, 6 and 7 are tied together. It should be pin 7 on the left side flipper opto button that runs over to the right side flipper opto button pin 6 to power the right side. Colors may be different, so do some measuring and testing in case they wired +12V strangely.

I'd connect an alligator clip to the grey-yellow wire, and briefly touch it to the piece of solder sticking out of one of the colored switch wires mentioned above while in switch test. That'll confirm that a simple switch closure works.

Buy some double stack flipper button switches, maybe like this?

https://www.marcospecialties.com/pinball-parts/500-6890-01

I personally always have breakaway headers like this:

https://www.marcospecialties.com/pinball-parts/CM10036

Break off enough of the pins for your connectors.

This would allow you to solder to the header, and plug it into the connector that would normally go to the opto flipper board. Using a plug in header allows you to go back to optos, or if you don't want to do that, some later owner of the machine would appreciate you not just cutting wires and splicing in.

On the left side you'll have to bridge the two pins that connect the grey-yellow... one grey-yellow wire supplies +12V, the other branches on the opto circuit board to make connection for the ground wire for the right flipper button. Just bridge both of these pins together on your breakaway pin connector, otherwise your right flipper won't have ground! Pins 6 and 7.

Solder jumper wires from your breakaway header pieces to your flipper switch contacts. You'll only need a couple of inches of wire.

Then it's just a matter of unscrewing the opto boards, and screwing in the leaf switches. Plugging your breakaway headers into the connectors, and using test mode to make sure things work.

It doesn't seem difficult, but again, pretty much nobody does this.

It's far better to just buy these if your flipper buttons don't have enough 'pushback' or are troublesome with the optical interrupt. Adding the spring steel really helps:

https://www.marcospecialties.com/pinball-parts/01-14348.1

I believe you omit the +12 volts and have each switch return drive by the ground.

That's a good one to try it on, its only got single switches on both sides.

Yeah, it's been a long time since I looked at this particular hack.

The only thing that matters is you present a compatible signal to the detection circuit. The detection circuit is a comparator (LM339). It senses the voltage. When the switch is open the voltage is +12V (logic HIGH). When the switch is closed the voltage is 0V (logic LOW). That's it. How you achieve the state difference is up to you.

Williams chose to use a slotted opto to do this. No reason why you can't use a leaf switch. No resistor or diode is required. Just a switch. Don't believe me? Just short the non ORG wire on either J905 or J906 to the ORG wire while in switch test. Or short any pin (except 6) on J905 or J906 to pin 6 (ground). Switches F1-F8 will register as closed.

wpc_flp.jpg

For a one off like this, of you are going to make one, just grab some veroboard and hand make one.

Note: use gold contact points.