Quoted from Rdoyle1978:

I followed the instructions from pinbits, but had to do a lot of figuring things out still - this is for instructions for adding it to a non-sample game, but you can figure most of it out:
http://iobium.com/third_magnet_project.htm
http://iobium.com/kit_contents.htm

Quoted from mbaumle:

The third magnet also changed the way the balls are grabbed during “the spiral” mode as well:

A mod definitely worth doing if you’re ever in the position to do a playfield swap.

Quoted from mbaumle:

If your sample has the 2 opto boards, instead of the single 10-opto board, wiring in the additional opto for the magnet should be as easy as running new wires and punching them into the existing connectors.

Quoted from hawknole:

Yes, those are opto plugs. Optos tell the magnets to engage. Look for similar 2 wire plugs that are plugged in to see if two are mixed up then change them all.

Quoted from DumbAss:

Third magnet is switch 82 (ORG-RED). Switch 86 (ORG-BLU) is NOT used.

The 2 pin connector (GRY/ORG-RED) is for the receiver (the blue opto board). You will need to find the connector for the transmitter (the green opto board). This should be a GRY-RED/BLK female connector. Typically these connectors are four pin connectors not two as the transmitter and receiver are paired for functionality. You can see one (further away) in the image that you posted.

Quoted from DumbAss:

<disclaimer>I have never worked on a sample Twilight Zone. I have never seen one. The manual is written for production machines and does not document anything about the sample machine. Everything here is based on the manual, observations from any images that you provide and deductions based on those observations.</disclaimer>

The board (front) that is visible in your image looks to be the column 8 board. The switch matrix connector has what appears to be a GRN-GRY wire indicating to me that it's column 8. The two connectors on the other side appear to have 6 orange wires and 6 gray wires off both of the connectors. These would be the six rows (81/83/84/85/86/87). I can't see anything further as the image resolution and lighting prohibits it. I don't see anything at opto 2 on the receiver side but there does look like there's a ORG-RED wire in the nearby bundle.

No need to. You have all the circuitry there to be able to simply insert or connector a wire from point to point. The (standard) custom 10-opto board for Twilight Zone supports 5 switches in column 7 and 5 switches in column 8. The sample machine used 2x 7-opto boards to support 7 switches in column 7 and 7 switches in column 8.
You are at the physical machine so you will have to do the digging around. The only way I can help further (other than the descriptions above) is for you to take more images of the wiring bundles and connectors. If you separate things out and take in focus and well illuminated images I can help you further.

Quoted from DumbAss:

Thanks. Excellent images. In focus. Well illuminated. Perfect.
You have all the wiring there. You will have to trace where it goes in the wiring bundle. I can't do that remotely. Just a reminder that there are TWO sets of ORG-XXX and GRY-XXX wires. One for each opto board. To be sure you are dealing with the correct opto board you will need to use a DMM to confirm the continuity.
For the most part you can ignore the BLK (kathode of the transmitter LED) and GRY (collector of the receiver phototransistor). Those wires are the same for all of them and they are all wired in parallel for distribution.
For the GRY-RED wires ... one goes to the rocket opto. That corresponds to the "left" opto board (as viewed when the playfield is raised). The other GRY-RED wire you will need to trace where it goes. It should go to a 0.062" 2-pin Molex female housing. Unless the wire wasn't stripped and just terminates somewhere in the harness. Again ... I've never seen one of these machines so I don't know what to expect.
For the ORG-RED wires ... one goes to the rocket opto. Same as above for the GRY-RED wire. The other should go to that 0.062" 2-pin Molex female housing shown dangling. Verify this with continuity.
Once you've located both the 2-pin Molex female housings you can simple install the transmitter and receiver opto boards on the top side of the playfield, drive the wires down underneath and crimp 0.062" male pins into a 2-pin Molex male housing and mate the housings.

Quoted from DumbAss:

That connector makes sense. The GRY-BRN and GRY-RED service the optos for the two magnets on the right. The BLK wire is common so it is daisy chained at the cathode (K) on the transmitter board. The 3-pin housing keeps the relevant wires together and also serves as a potentially different connector to avoid confusion when reconnecting.

Common expressions:

Ancient: don't judge a book by its cover.
Old: don't judge a person by their attire (the way they dress).
Modern: don't judge a Pinside user by the "tag" or "handle".

Glad to have been able to help you and any other potential sample owners in the future.

Quoted from Manny65:

Not sure what the prototype/early release machines have but the production machines use a micro-switch (switch #43) [quoted image]

Quoted from DumbAss:

First off: most all of the information you will ever need to service your WPC pinball machine (not just Twilight Zone) is in the manual. I think most people don't read the manual because the information can be daunting. My advice (not that anybody solicited it) is to read the manual, read the manual and then read the manual. The more you read it the more information will sink in. With enough information you can deduce things.

Thanks. One picture has the evidence needed.
This is the image from the thread. The wire color gives it away.
[quoted image]
This is the image from the machine (BadBrad97) that was first posted. The connector is for the receiver. I suspect there is another connector somewhere that is for the transmitter. The right 7-opto board has the wires for this and that opto board is column 8.
[quoted image]
This is the switch matrix.
[quoted image]
It's unused. The software registers the state of switch 82 and describes it as "NOT USED" and it will probably register this switch (86) when closed (actually open if an opto). It may not actually have any coding that uses the switch state. You would need to look at the disassembly of the software to see if there's anything there. Perhaps Ted Estes or Coyote would know. It probably got removed early in sample/prototype production.
Perhaps cost cutting? Perhaps the fact that the machine used 13 optos (2x 7-opto boards) and maybe at the time Williams didn't have the 16-opto board or at the very least did not have it at the time the machine was manufactured and re-wiring everything to use a 16-opto board just wouldn't work? Perhaps another reason or combinations of any of those reasons?
Column 7 has 6 available switches but only used 5 (switch 71 is unused although it does have the wiring). Column 8 has 7 available switches and all 7 were used. However, the 3rd magnet (switch 82) was removed leaving 6 switches used. That means 11 optos are required but an 11-opto board did not exist. The problem with supporting 11 optos using the LM339 quad comparator is that 10 optos use exactly 3x LM339s. To support the extra opto would require an extra LM339 and only one of the units would be used (leaving 3 unused units). That's a waste. Not only that it would require another new board. Instead ... remove switch 86 leaving 5 switches used for a total of 10 optos required. Make a single custom 10-opto board to support this and use 3x LM339s and a custom board that supports 5 switches in column 7 and 5 switches in column 8. Plus ... you save the cost of the wiring and the transmitter/receiver boards.
The above is pure supposition. I don't know the history. I only see the evidence of what is present and what can possibly explain it.
I believe that engineers (and most people) often choose to do things with a very good reason. Figuring out the reason why is the puzzle. Expiring minds want to know why.

Quoted from BadBrad97:

No way! You mean I have to track down and hook up another opto? This is turning into a nightmare. (joke)

Quoted from gameroompinball:

Mid game DMD issues started and now this on startup. Any idea where I should look first? Any help would be appreciated. Thanks
[quoted image][quoted image]