(Topic ID: 143563)

STTNG mixing GI OCD and KBOP mods issue.

By Patofnaud

4 years ago

Topic Stats

  • 47 posts
  • 7 Pinsiders participating
  • Latest reply 3 years ago by Zitt
  • Topic is favorited by 9 Pinsiders


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#1 4 years ago

There are some must have mods for STTNG three I will talk about are:

Installing the "Hallmark" ornaments. One in particular I am going to talk about is the Klingon Bird Of Prey (AKA: KBOP). (Ref: http://www.pinwiki.com/wiki/index.php?title=Star_Trek:_The_Next_Generation#Klingon_Bird_of_Prey_Mod )

Here is the difference in detail....


And once you have the KBOP, you need to install Zitt's modules instead of the original crappy #47 bulb holders. Ref: ( http://pinball-mods.com/blogs/?p=452 )

With ZITT's modules you can trash the ugly old dual #47 holders...


And get a low profile solution that looks really nice..


And of course if you want to run LED's to really make your machine pretty, and if you do and leave everything stock, you will have problems with your GI and especially on STTNG the 'Shields" as they are GI and not feature lamps. The issue is STTNG has the ability to dim the GI and uses that ability to dim the shields as your getting hit in multiball. Unfortunately LEDS + lowering AC voltage do not = pretty dimming.

So you will need a solution like the GI OCD (Ref: https://pinside.com/pinball/forum/topic/gi-ocd-active-smoothing-for-gi-work-in-progress ) to change those AC waveforms into some nice PWM-esque wavefoms to cleanly dim LEDs.

Now what I found was the KBOP + ZITT Mods + GI OCD does NOT work nice at all. In fact you will run for about 3 minutes before you notice that the KBOP is no longer illuminated, and a few GI lamps.


#2 4 years ago

The problem...

The KBOP is a Christmas ornament and will work on 6VAC. In fact it has logic inside to flash a little Photon Cannon in the nose along with a few other LED's inside.

The GI OCD outputs more of a DC waveform and while the KBOP will 'work' on DC you will only like half of it depending on your polarity. So you may get the interior lights OR you will get the Photon cannon. But you will not get both with a GI OCD installed.

Not earth shattering, but then lets add in ZITT's modules under the wings of the KBOP.. Those modules have a bridge on then to allow use of AC or DC to feed then. And while they will run on either, the boards just pass through to the KBOP and the KBOP only 'likes' AC for full use.

Now lets top this off with the ZITT boards having the 6 LEDs alone pulling ~130mA at full brightness (IE 21mA per LED), plus what the KBOP draws, plus remember the bulk rectifying caps on the ZITT boards are surging to keep the LEDs going during the non-peak of the incoming waveform,,, basically after about 3 minutes you blow the 2A GI fuse for that string on the GI OCD. DOH

In talking with Herg, I could probably safely install a 2.5A fuse in the GI OCD and be done with it. However, I would have a crippled KBOP for the reason stated above with AC input vs. DC input.

So how to fix this and have a fully functional KBOP?


#3 4 years ago

Well the facts first...

The GI OCD knows when to dim GI because it intercepts the CPU to driver board control signals by changing the 2 female end cable into a 3 female end cable and adds itself as a watcher of the control signals that would normally just go to the Power Driver. The driver still gets all signals but now so does the GI OCD.

The GI OCD redirects all input 6.3VAC that went the Power Driver over to itself through the use of a Z connector. The Power Driver is now getting no AC on J115.

The GI OCD removes to GI outputs of the Power Driver and hooks the to its own modulated outputs via Z connectors.

The Power Driver is still fully functional with the exception that the 5 circuits used previously to control GI are now orphaned.

These facts are important when I talk about the fix.


#4 4 years ago

The fix...

The fix is to give the KBOP what it wants, AC voltage. We can accomplish that with a $5 wall plug, but that is cheesey,, and but the rub is we want the voltage to be controlled by the CPU so it goes out when it is time to go out.

What I did is steal back the original AC voltage that the GI OCD is now using to wake up that original orphaned logic on the Power Driver, and the rewire the new KBOP back to the Power Driver into the connection that the GI for its circuit 'used' to be plugged into (but is now plugged into the GI OCD).

Step by step..

Disconnect the KBOP from the GI OCD controller Playfield 2 GI string (white-green).


Make a hardness that has a male version of the factory connector of the KBOP. Plug it in and route it cleanly and back up to the head.


On the other end, you want to connect to pins 6 and 10 of J121 (or J122, they are wired the same)


Now, we need to steal back some 6.3vac from the GI OCD (remember the logic is dead on the Power Driver... So what I did was take the Z connector that reroutes the input AC over to the GI OCD and solder a couple wires on the Z connector and over to a 12 pin connector taking pins 5 and 12 back from whence they came.



#5 4 years ago

The result after all this... I'm happy..

#6 4 years ago

Looks great! And the best part is you didn't clear my high score!!

#7 4 years ago

Nice job.

Anyone trying to replicate this, be aware, Patofnaud has an older revision of GI OCD. The new ones don't use a Z connector for the power input. They have a cable that runs from inside the cabinet to the GI OCD. The same fix can be done by making a splitter for that 9-pin molex cube connector.

#8 4 years ago

Ron! Lord knows I am trying. Hard hard game. I need to have you come over and really check it out.


Thanks for reminding me. Yes, I was an early adopter for the GI OCD back with my Demolition Man, then was moving it to my T2 when I got the STTNG. It is not as 'purdy' as the newer versions. And thanks for the help when I was trying to figure this out.

As a side note there is some mods you can do to the GI OCD to add a switch and I could have feed my KBOP from the main transformer and used the switch capability of the GI OCD by adding a couple minor components, but I chose to revive the Power Driver board logic and let the CPU do the work.

5 months later
#9 3 years ago

So what needs to be done to get this working with the newer version of the GI OCD board? Can I just jump a couple of wires from J2 on the GI OCD board to pins 5 and 12 on J115? If so, does it matter which pins on the OCD board end?

#10 3 years ago

Also, am I correct in thinking that the connection that's currently on J115 (the original one) can be removed?

#11 3 years ago

Everything would be the same except when I soldered and stole off the Z connector, as Herg (who developed the GI OCD) says above:

Quoted from herg:

The same fix can be done by making a splitter for that 9-pin molex cube connector.

I don't have any pics of that newer set up. Maybe Herg can be so kind?

#12 3 years ago

Thanks! I went ahead and cut off the connection at J2 (sorry Herg!) and remade it with a couple of extra wires running to another connection I made at J115, pins 5 and 12. Then gave it the same treatment as you, with a connection at the now empty J120, pins 6 and 10, running down to the KBOP. I can't wait to get the game back together so I can see everything in action!

#13 3 years ago
Quoted from mskoenen:

I went ahead and cut off the connection at J2 (sorry Herg!)

No need to be sorry. It's yours now.

I would have built a splitter for the connection in this picture, mostly because that keeps it a little "cleaner" inside the head. If you do this, you DO NOT want to connect the middle GND pin since the GI OCD runs the AC through a bridge rectifier. The GND pin would cause a short due to different GND references.


#14 3 years ago

I ended up using pins 3 and 7 from that connection, only up at the GI OCD board end (I forget which pins they ended up being on that connection). I chose them since they were the ones that originally terminated at pins 6 and 10 (respectively) on J115. I'm not sure if it made a difference, but I tried to keep to Patofnaud's original design.

#15 3 years ago


#16 3 years ago

Whelp... I'm not entirely certain what I did wrong. My KBOP is not working. Here is what I know:

The KBOP works, I hooked it up to a benchtop power supply before I mounted it to the playfield and it lit up like a Christmas tree (ornament).
I seem to be getting less than 6.3vac. I forget the exact number, but it was somewhere between 3-4.5.
Every once in a while, the KBOP briefly illuminates but then powers down again.
I have pin 6 on J120 running to what was the white green connection of the KBOP.
I have pin 10 on J120 running to what was the green connection on the KBOP.

Does anyone have any clue what is wrong? I should be getting 6.3VAC at my new KBOP connection, right?

#17 3 years ago

If you are using my KBOP WingLEDs; you have to have 6.3VAC in for it to work.
3-4.5V won't cut it because the LEDs in the ship needs ~= 5VAC (not sure of the lower limit).
Make sure you are measuring the input to my board in AC mode just incase you accidentally measured with DC.

If you run with a DC voltage into the ship... it would manifest itself as either the body/lower yellow led being on... or the cannon flashing with impulse engines or something like that. This is why you HAVE to have AC into the ship.

It sounds to me like your ACin is too low for the ship to operate properly; and that occasionally - you have surge in input voltage which causes the ship to briefly light. I'd recheck the connections and verify you don't have any aged/burnt connectors between the ship and the secondary side of the transformer.

#18 3 years ago

First, make sure you're getting 6.3VAC on J115. If so, try going into the game's test menus and try GI brightness 8.

#19 3 years ago

I like watching all of the videos on YouTube that I can find with a Led Ocd or GI Ocd search.
I just realized that I have seen your TNG before!
I wish you had longer videos of them!

#20 3 years ago

I am not getting 6.3vac on J115. I'm getting about 4.5vac there as well as at J2 in the GI OCD board.

I also tried to go into the menu to check the GI brightness. I had to plug the dmd in for the first time in a few weeks, since I've been in the middle of tearing the machine down for a thorough shop job. I now see that in getting a "slam tilt switch is stuck closed" error. My coin door is completely disassembled while it's off getting powder coated. Anyway, do you think that error could be the reason I'm not getting the right voltage?

#21 3 years ago

I'm also noticing that the LEDs on the LED OCD board are not on... Should I create a new thread?

#22 3 years ago
Quoted from mskoenen:

I'm also noticing that the LEDs on the LED OCD board are not on...

Was the OCD working prior to your doing the KBOP mod? If so keep it here. If not then you may want to start a thread, but first, there are a few 6.3vac inputs to the GI OCD, are all of them at that voltage?

Quoted from Giraffejumper:

I like watching all of the videos on YouTube that I can find with a Led Ocd or GI Ocd search.
I just realized that I have seen your TNG before!
I wish you had longer videos of them!

giraffe, was that pointed to me? Or Herg or Zitt?

#23 3 years ago

The 6.3VAC input comes directly off the transformer secondary, and the game does not really have any control over that voltage you would see on J2/J115 other than a problem with the game making it sag or a problem with the transformer.

Are you measuring it correctly? I don't intend to be condescending, but a lot of people measure it incorrectly, using GND as a reference. AC should be measured with one DMM lead on each of the two input wires.

Quoted from Patofnaud:

Was the OCD working prior to your doing the KBOP mod?

That's a good question. If it was, you should be able to disconnect J115 and get it working again, assuming the cable is OK and you didn't mess up anything on the GI OCD.

If you do decide to start a new thread, make sure to link to it in this one so that your help follows you. It would also help others who are trying to do this mod of a mod to be able to see what you go through.

#24 3 years ago
Quoted from Patofnaud:

Was the OCD working prior to your doing the KBOP mod?

That is a good question, and I'm not certain of the answer. I'll try unhooking J115 and seeing if the LED OCD fires up.

Quoted from herg:

Are you measuring it correctly? I don't intend to be condescending, but a lot of people measure it incorrectly, using GND as a reference.

Not condescending at all! You were correct in your thinking, I was measuring it incorrectly. Should all pins at J2 on the GI OCD board be getting 6.3vac?

Depending on what I find when I get in front of it later today, I may make a new thread. If that happens, I'll be sure to link it here.

#25 3 years ago
Quoted from mskoenen:

Should all pins at J2 on the GI OCD board be getting 6.3vac?

Pins 1,2,3 are one terminal, and 5,6,7 are the other. If you read between 1 and 5 (or 2/7 or 3/5, etc), you should see 6.3VAC.

#26 3 years ago

My "new" wires are on pins 3 and 7. When I test it with one DMM lead on each, I'm seeing 7.77vac. Am I using this DMM wrong?

#27 3 years ago

Since it depends on your line voltage and the drop through the transformer, the actual voltage can vary a bit. Normally, I see about 6.8VAC for an actual measurement. 7.7 seems a little high, but it should not prevent things from working.

You say that the KBOP isn't working, and the LED OCD status LEDs aren't lit. I didn't see you mention whether the GI is lighting up, though. Did you mean to say the GI OCD isn't lighting up, or did you really mean LED OCD? If the latter, that is completely separate, and it gets its power from the lamp matrix column outputs.

#28 3 years ago

Thanks, Herg. The GI is mostly lit. I killed a fuse on the GI OCD board, but that will be fixed as soon as I get back in front of it with the new fuse. The LED OCD board is still dormant, none of it's onboard LEDs are illuminated or blinking. I'm not sure if that has something to do with my game displaying "SLAM TILT SWITCH IS STUCK CLOSED". None of the controlled lamps are cycling like normal during attract mode.

#29 3 years ago

Does it matter what gauge wire I use to run the new connections I made? Right now I have 18 gauge stranded wire running from the GI OCD board to J115, since that was all I had. Then the same wire gauge running from J120 to the KBOP. should I be using a smaller gauge wire? When I was out buying new fuses I also bought some 22 gauge and 20 gauge wire.

#30 3 years ago
Quoted from mskoenen:

The LED OCD board is still dormant, none of it's onboard LEDs are illuminated or blinking.

Quoted from mskoenen:


That is the problem there. The LED OCD is waveforming the incoming insert lamp signals. Where as you are stuck in SLAM mode, the game is in a quasi game over mode and none of the inserts would be blinking... No blinky, no LED OCD blinky.

That needs to be fixed.

And 18GA should be fine, the 7.7vac should be fine. Isolate and fix the slam issue first. Check the slam switch in the door and on the cab side wall.

#31 3 years ago

Yeah, they're both fine. But they are just sitting on the bottom of the cabinet while my coin door is off getting powder coated. I most likely have a short somewhere. And as I think about it, there is a grounding wire that isn't connected to anything at the moment...

#32 3 years ago

giraffe, was that pointed to me? Or Herg or Zitt?

Lol. It was you and your TNG, but I've watched everyone's ocd videos a million times. One guy put one on a Star Trek Pro. I thought that was awesome also

(I don't know how to do the quote thing here)

#33 3 years ago
Quoted from Giraffejumper:

(I don't know how to do the quote thing here)

Just highlight what you want to quote and an option to quote should pop up.

#34 3 years ago
Quoted from mskoenen:

Just highlight what you want to quote and an option to quote should pop up.

Thank you!

#35 3 years ago
Quoted from Patofnaud:

That needs to be fixed.

Okey dokey! The slam tilt issue has been fixed. It was a very deep and complex issue that took the full might of my illustrious brain to resolve, and totally not a ridiculous error on my part involving a connection being improperly reinstalled on the MPU...

And, wouldn't you know it, my brilliant deduction on that issue was so profound that it resolved the KBOP problem, too.

Thank you Herg, Patofnaud, and Zitt for your help! My KBOP is ready to help me against those pesky Romulans now. Sorry for the runaround from my boneheaded mistake!


#36 3 years ago

One more quick question. How warm are these boards/LEDs supposed to get? Mine are very hot to the touch. I used my IR thermometer and those LEDs are clocking in at 120 degrees.

#37 3 years ago

120 F?
IF so; are you sure it's the LEDs and not the bridge rectifiers on the board? 120F = ~60C which should be within spec of the LEDs.

If you are really concerned; use the brightness pot to turn down the brightness which will reduce power consumption considerably.
IIRC; I designed the board to run "in spec" at 20ma per LED - even when the pot is effectively 0. So "in theory" you can't cook the LEDs off the board.

There is one pot for each wing.

IMHO; the purple is a little overwhelming at full brightness... but it's your machine.

#38 3 years ago

Thanks, Zitt. I'll tone it down a bit, I think.

#39 3 years ago

Grats! Mskoe!

And Giraffe, no worries. I've a bit more STTNG work to do and I'll post more vids.

#40 3 years ago

Ok, so slight issue just popped up. One of the wings caught fire. Turned on the game to try test the cannons after I reassembled them and immediately noticed smoke coming from the KBOP. Shut the game off and the right wing was in fire. I pulled it out of the game and booted if back up. Voltage connection still shows about 4.8 vac. Any ideas why this happened?


#41 3 years ago

Ouch! Hard to see/tell from a pic. But, the mod you did still maintains the fusing on the power board and as you still have voltage it is probably not input related.

Solder bridge? Screw toughing component? Bad component? Maybe Zitt can look at them?

#42 3 years ago

Send an email via web site.
We'll get this covered under warranty.

#43 3 years ago
Quoted from Zitt:

Send an email via web site.
We'll get this covered under warranty.

Thank you, Zitt. E-mail sent through pinball-mods.com.

#44 3 years ago

Also, for an electronics rookie, where is the brightness pot on the board? Is it R11?

#45 3 years ago

Yes. R10 on one wing... R11 on the other. Looks like a screw head.

#46 3 years ago

What should one use to adjust? A tiny driver or something special?

#47 3 years ago

tiny screwdriver is the correct choice. I've used "jewelry" mini screwdrivers; anything that fits the pot head.

Feel free to take any WingLED specific support questions to the thread on the product:

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