I wonder if the fact that I have all my bulbs removed from my backbox is mucking things up. I mean, apparently the backbox and the clock are tied together. Could I be disrupting the circuit by removing my bulbs? I'm waiting on new LED's from Comet. I will install the bulbs before reverting the connectors to the PDB. Tomorrow if I'm lucky.

No. Backbox and playfield are different.

Do you have power leaving GI string 3 from the power driver board ?

LTG : )

Which pinout from the PDB feeds GI string #3? Looking at page 3-32 in the manual now but not seeing it.
Closest I see is J114-3, Gray, +5VDC to J210-5, but J2xx is the CPU.

Take you meter, set to AC. See if you have AC on all the playfield lines leaving the driver board. If so then see if power is getting to the clock board connector for the LEDs.

LTG : )

Swap backbox and playfield connectors on the driver board. If clock doesn't light up you know it isn't a board issue. Then from the connector to the board in the clock you have a break.

LTG : )

J120 and J121 have exact pinouts. And yes, it means the clock's GI is Yellow and Yellow/White.

I just want to say, that out of all of the groups I am and have been a part of this has by far been the most helpful and positive. You guys are all great ambassadors to the hobby.

We're all unusual in this group here. It's the Twilight Zone, after all.

I absolutely agree with this! Thank you, all

I'm probably the biggest help hog up here right now, so, at the very least, I should second this sentiment. Thank you, nerdygrrl, Coyote, Manny, and LTG in particular. Y'all da' best!

Here is what I believe is the connector that supplies the clock power, excluding its movement.
The yellow/white on the far left measures 10VDC. Is this the yellow/white that originates at J121-3? Seems like plenty of juice for the clock LED's.
LED OCD remarked that it could be a polarity issue.
OCD board may be providing the wrong polarity.

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I am loving all of the trouble shooting. Have you been keeping a blog of your project? I am so curious where and what you started with.

I am feeling pretty good about this. The re-population has been going much smoother than I would have thought. I am hoping to wrap everything up tomorrow and get it back to my friend on Sunday. This has definitely been a fun one to clean up.

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Looks awesome.

Yeah, 'older' LED's are polarity specific. In the GI, just rotate the bulb 180° and put back in. I think with the clock LED's you would have to unsolder and flip them. I'm running both OCD boards and did have a few bulbs at first that I had to flip, but my clock LEDs worked fine. Another thing is the 'regular' modern LED's work great with the OCD boards... the non-ghosting ones won't work properly.

If you are using most boards OTHER than Ingo's and OEM, yes, they have their polarity wrong for the OCD boards.

This is ONLY an issue, though, if the lights on your backbox that are part of the same string (the title in upper center, and lower right behind the art of the clock) are ON and working normally.

You installed the OCD board and then the LEDs on the clock no longer work? The + and - pins to the LED lights on the clock need to be swapped. The reason the LCDs on the clock are not working is because of the polarity. GI J120-9 and J120-3 (White/Yellow) Swap these two wires by removing the wire from the back of the modex connector. I used a small screwdriver to push the pin & wire out of the molex connector. Make sure you are swapping the correct pair. (Double check me and confirm it really is J120-9 and 3.)

Since it's normally AC, and is only DC with the OCD board, it won't stop an OEM board from working if it's ever plugged back in.

The boards came from Marco. And were working until Jason was trying to get the flippers going and other things.

LTG : )

Yes, Marco's board they sell, then, won't work with OCD without reversing GI string wires. Was brought up recently here or in another thread a few months back.

I'm thinking if a potential fix would be to install a small header jumper on the LED clock board - it could be configured for "Normal" and "GIOCD" and would reverse those feeder pins if you add the option.

It could be done as a revision on the PC board. Makes me wonder if it's worth the effort - just how many TZ owners are using the GIOCD add-on? Maybe time for a poll....

Honestly, I just got 2 single-pin Molex connectors on the harness, and used tem so they can be flipped - unhook the two connectors, and reverse the wires.

Edit: However, if I was to design a LED clock board, I would just add a bridge-rectifier, so it doesn't matter which input wire is + and -, honestly.

That's one possibility, but there is a voltage drop in the diodes which would decrease the intensity of the LEDs. And, the drop is multiplied x2 because it's a bridge.

That said, the jumper is kind of a PITA as most people don't understand those little things....

OK guys I am stumped. I walked away last night, and revisited it today and I am still stumped. Can anyone tell me where the white opto for switch 81 (right magnet) opto connects to?

Per my breakdown pictures its line runs straight up the right hand side of the PF and exits at the hole on the top right. I labeled my connectors and truth be told my handwriting is atrocious, but it appears its mate is on the center top of the PF opposite side(marked with the blue tape). I have looked everywhere for another option, thinking that maybe the other line says 24 instead of 21 and don't see it and every other plug has lined up nicely.

I am truly stumped. There is no way this will reach across the PF and I don't see any other connectors without a mate.

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I believe that the Grey/xx colors should match. The plug for that opto looks like it is Grey/Orange. The wiring harness I can not see. Grey/Orange is the right ramp. (Powerfield ramp.)

Guessing that you have those reversed. While the Grey/x colors don't matter (i.e. one white LED is the same as another), it looks like you got them reversed.

LED and Opto colors are on page 3-16 of the manual. If you have a sample game (does not look like you do) the manual's wires should match up, color-wise.

Thanks, the manual is telling me opto in question should be green-grey, and orange-brown. This is like a black and then an orange-grey. I can't see how I would have mixed them up as they didn't get removed until I went to clean the ball guide and then they went right back on.

I'll go back down tomorrow and reverify the colors.

Maybe they were wrong before you started ?

LTG : )

Always blame the previous guy

Luckily my friend did a tear down on his before I started this, I had him save his photos and he's got some helpful shots. I'll tackle it tomorrow after some sleep. Amazing how something so small can derail your progress.

Jeebus, if I had a nickle for every time I had to diagnose work affected by a previous owner, another tech, or a less-than-stellar distributor service job back when I was an operator... I'd have enough nickels for a coin pusher.

So I think this is what you were saying. The ball guide in question has optos for both switch 81 and 83 on them and I have those reversed. And if so, yes, why I do believe that is it. Many thanks for the assist!

Good luck.

Now that I'm home, I can check my game. However, I have a sample game, so it may not match what you're working on there.

That was definitely the problem. Swapped them around and all is well in the world again, all except for that silly mini pf. I just fought with the stupid post lamps and the mini pf for the last three hours. The long Cliffy doesn't seem to fit well either. It's near impossible to get it around the nut. I ended up removing it. So much for wrapping this up today. So close, yet so far.

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It will be better tomorrow.
As Rudy says, "hey, its just pinball"

You're very clever. Raymond at LED OCD also told me it might be polarity.
I've never had any luck extracting a pin from a Molex connector, but I will try. LED OCD is hoping to fashion an adapter for me to try. Perhaps they will send it out next week.
Thanks for your input!

Do you mean you struggled to pull the old bulbs from those sockets? I can relate! Those two are devilish! You can't grab hold of them to do any real pulling. Or perhaps you're just talking about the star-post lights.
Your shop job is amazing. Mad props to you for doing such a thorough job.

Push tab in on the back of pin and pull up and out.

LTG : )

Or buy a cheap molex extraction tool

Sadly no, my friend wanted the start posts lights installed and they were a PIA with the limited clearance on the pf.

Hi again. Please see the attached photos to help me confirm that J120-3 and J120-9 are indeed the wires to swap at the PDB connector.
I heard from Harold at LED OCD and his suggestion was to swap two pairs of wires at the clock board. This seemed impossible as I can't possibly swap them inside the housing. Do I instead swap them at the clock's connector to the wiring harness?
And again, has anyone else had a clock GI issue after installing a GI LED OCD board?
Thanks.
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Clock GI Cont'd:

I realize there's a good chance I'm wearing out my welcome with my endless questions regarding my clock's GI, but I heard from Harold at LED OCD and his advice was conflicting with suggestions here and hard for me to understand, in part because in my game J2 is a 4-pin connector. Would you mind taking a quick look?

From Harold at LED OCD:

(Quote)

Jason,

From the TZ manual, the lamps are lit by wires connected to J2. Pins 6 and 5 are the positive terminal, pins 3 and 4 are the negative terminal.
image.png

Swapping 6 with 3 and 5 with 4 would allow LEDs that are turned the other way to light.
image.png

For an adapter, you could get a 0.1" pitch connector that would connect to J2, another that is male pins, then wire as below.
1-1
2-2
3-6
4-5
5-4
6-3
7-7
8-8

That said, I don't have a schematic for Casper's board, so I'm going from what I can see in that picture. It really looks like pins 5 and 6 are labeled C2 and C1, and the + terminal of the LED strips are as well. Based on this, I'm surprised they're not lighting. If the LED strips were rotated 180 degrees, they would still light when fed with AC power (normal GI), but not light if fed DC (like GI OCD).

One other possibility would be that they are connected the correct polarity, but the brightness setting of the GI OCD is not enough to light them brightly. You could try turning up the brightness using the PC software.

(End quote)

Notice how much more involved this is than Mickpat's idea about just swapping J120-3 and J120-9 at the PDB.

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You are looking at the WRONG BOARD. That is the MOTOR board, not the CLOCK board. Look in the manual for the Clock Minute Opto board, I believe it's called. (On phone, can't open manual at the moment.)

See this post for a photo.

https://pinside.com/pinball/forum/topic/twilight-zone-owners-club/page/205#post-6229494

Thanks.
I just tried this.
First, though, I reverted to stock (took the LED OCD GI board out of the equation) and my clock's GI returned.
I then swapped J120-3 with J120-9 to switch the polarity and re-installed the OCD board. No clock GI.
Now I will return the wires to their stock positions.
Oh, I also reverted to stock but left the J120-3/9 swap in place. Clock GI returned.
I'm discouraged.
I mean, even if I make the adapter proposed by Harold at LED OCD, I don't foresee it helping as its purpose is simply to reverse polarity.
Does it make any sense to buy a different clock board? One from a different vendor?

Looking at my original posts, it looks like it might be J121. You can check by confirming this group of wires runs to the underside of the playfield.

Thanks for the heads up. I'll try again.

Thanks, Mickpat.
J121-3/9 was the charm.

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Oops.
That was embarrassing.
I thought every connector has a unique address. I found J2 on the motor board and assumed I'd found the connector in question.
Rookie!

This is true, but only for boards up in the backbox.
Everywhere else (i.e. Playfield & Cabinet), they all start with J1 and so on. (I'm sure there are exceptions there, but...)

I recently purchased a Twilight Zone, WOW i love it, i cant believe it took me this long to purchase this game, its defiantly one that will not be leaving my collection,
I have been purchasing a few mods over the last week that i will be adding to the machine,
mods are as follow. some i have purchased and some that still need to be purchased.

spiral arrow, camera, Robbie the Robot, Highly polished gumballs, sparkler circuit for gum ball machine, door flasher kit, diverter magnet, slot machine, decals for the ramp and diverter, millions clock, invader, town square street light, interactive pyramid topper, rocket ship mod, piano mod, 1955 red thunderbird with LEDs, custom spiral sign, custom mini playfield light, pingraffix art blades, color dmd, mirrored translight, pinvision, cliffy protectors,

I am also going to purchase the clock LED board, as far as i know the only 3 available are ingos, caspers and rottendog, after doing a bit of research on this thread it look like that Ingos was the best one to purchase, i actually purchased this through there website, paid for it but a couple of days later i received a full refund, does anyone know if these are still available? or if they are not shipping atm due to all the shipping issues we have at the moment due yo COVID.

Any other mods or information you can share about this awesome machine.

cheers
Trevor
Brisbane.

Whoa! No expense spared! Impressive. Not sure where you found them all. Many of these are very hard to find Stateside. Congrats!

thanks, hours and hours or internet searching and high prices.