Movie Prop help

Thread Starter


Joined Aug 12, 2011
Ok guys,
I need some help. If you are a star trek fan, you might remember the scene in the movie Generations, when data opens a panel in his arm, and uses the servos to open the sealed door. Inside the arm are many leds all blinkng away etc.
Here is a pic if the arm being used.

I am trying to get the arm to light up again, and it came from the storage warehouse to me with this connector attached to it, ie the original.

INside the arm, i can see many resistors, and also two, pencil thickness in width, black tubes. I think these are used t cause the red leds to cascade like knight rider. Bear in mind, this was made about 12 years ago.
I think i need to get a female connector of the one shown in my pic, but i have NO idea how to actully power it, apart from knowing it needs to be a DC supply.

ANY help apreciated. Heck, if someone can get it to work,i am willing to pay for that!
More pictures, lots more pictures, especially of the "arm" circuit(s). Just looking at the connector with all the pretty colored wires doesn't tell us what-goes-where.

Pretty cool!

:) joe


Joined Apr 24, 2011
You have the actual movie prop? Very cool. That's a D-Sub connector, you need a D-SUB Receptacle with 15 positions, something like this.

You could just cut the connector off and wire direct to it, but that would lessen the quality of the "artifact."

I would not put any power into that thing till you well understand what it is going to. Can you post pictures of the inside of the arm?


Joined Jul 17, 2007
Very cool, indeed! :cool:

What ErnieM said - don't cut the connector off.

PC's very frequently had "game ports" on audio cards back during that time; they used DB-15 receptacle connectors that would mate with the displayed male connector. DB-15 extension cables could be purchased at any computer store very cheaply. HOWEVER! This is absolutely no assurance/guarantee whatsoever that is what was used; simply a possibility - and I am certainly not suggesting that you try connecting it to one. It would, however, have been an easy way to both power and control the LEDs and their flash patterns with the technology available at the time. It would've been a lot easier to find a PC game programmer than to find a microcontroller programmer, too.

The layout for the old gameport is here:
Here is a link to a place that sells 10' long game port extender cables:
You would need the one with the female end; on the left. You should consider getting several; they're cheap anyway. If you're going to use the arm in a movie, you'll either need to have extension cables, or design a microcontroller interface and use batteries that would fit inside the arm without making alterations to it.

I'm guessing you're in California?

The pencil-sized black tubes - isn't that what the rows of red-orange and green LEDs are mounted in? The tubes were most likely just there to disguise the printed circuit board underneath the LEDs; making it look more "high-tech".

Any chance you can get a frame-by-frame of just that portion of the scene where the LED flash pattern is shown? You know that if you make a film/video using it and the flash sequence isn't correct (same as last time), nerdy trekkers will haunt you. ;)
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Thread Starter


Joined Aug 12, 2011
Hey all,

Firstly, I am going to get some high res pics of the internals, as thats the only way you cleaver guys can work out whats going on.

Yes, its the actual prop from the Movie, I have a lot of original screenused props from trek, a bit of a hobby of mine.

I am trying to track down the prop master, easier said thn done, but i have some contacts in that world so hopefully that will help.

The black rods actully have wires coming.going from them. The pics will explain all. I will post some up asap. I do think that the old pc port idea is on the right track. I can easily get female connector, but i dont understand how to get power into it. I could just buy an old motherboard with a psu, and the required connector and see what happens, but i dont want to blow anything in there


Joined Jul 17, 2007
NO, don't connect it to anything yet!!

If you should happen to burn anything up, it will have to be repaired - and that might not only prove expensive and difficult, but it will result in the prop no longer being in original condition.

LEDs usually have a reverse breakdown voltage in the neighborhood of 5v. If the voltage used for testing is kept at 4.5v, there should not be much risk of damaging the LEDs by exceeding that. The power supply should also be current limited, as right now there is no knowledge of what's connected to what inside the arm.

But, the joystick port has four +5v out pins, and three ground pins. There are also four "button" pins. What I'm thinking is that they used the button pins as control pins to turn transistors on and off, that controlled the LEDs in the arm. Four inputs being sequenced as 0011, 0110, 1100, 1001 would be all that one would need to produce a "movie marquee" effect making the LEDs appear to move up or down (or both) the arm.

Or, they might have just used something like the gameport for power, and there is a timer used as a clock and something like a 4017 Johnson counter on a board in the arm, so that the sequence is generated within the arm - that would be a simple way to generate a marquee sequence with minimal parts required. If there ARE IC's in the arm and you power it up incorrectly, you'll destroy the ICs.


Joined Jul 17, 2007
On further examination of the DB-15 connector ribbon cable, it appears that the brown wires that went to pins 1 and 2 were cut.

On a game port, that corresponds to one of the +5v out pins (1) and button1 (2). There goes the theory of the movie marquee effect using button1 thru button4.

But now that I'm looking at the joystick port definitions more, I see that the PC only outputs +5v and GND - the rest are inputs. It IS possible to use pins 12 and 15 independently of their original functions (GND and +5v, respectively) as they were used in MIDI.

Thread Starter


Joined Aug 12, 2011
OK, here are the pics. If you need any clearer ones, jut ask.

There appears to be 3 circuts as it were, so I have broken this down into those 3 for simplicity.

First, here again is a pic of the connector. Notice how the wires coming off this split into different colours using the black connector things.

'circuit 1'

Coming from the black connector thing, these wires go into this board.

There are resistors on board,

which in turn then power these small type leds things.


Thread Starter


Joined Aug 12, 2011
Circuit 2

These 4 wires are NOT on the pc connector thing, these are just bare, stripped wires

which in turns, are joined inton different colours here

these in turn go to the black rods thing i mentioned. i now actully think these are blue light, that light up the inside to gove it a blue glow.

Circuit 3

coming from the black connector things, are these 6 wires

these go to this, it contain the lights that cascade, and also static ones on the plastic itself



Joined Jul 17, 2007
Circuit 1 resistors & board
The PC board is a piece of Radio Shack catalog # 276-150; they used it as sort of a "junction box".
There are traces connecting the holes as shown. Those two brown wires look like they're about ready to break.

red red blk gold = 22 Ohms, 5% tolerance. This is used to limit current for the red rectangular LED.
brn blk blk gold = 10 Ohms, 5% tolerance. These two are used for the yellow and green rectangular LEDs.
This gives us a hint as to what the original voltage supply was. It looks like there are four green LEDs total, two yellow LEDs total, and two red powered via those three resistors.

Orange LEDs are powered in parallel by the yellow wire & 10 Ohm resistor
Green LEDs " " in parallel " " green " & the other 10 Ohm resistor
Red LEDs powered in parallel via the red wire & 22 Ohm resistor

There is one lone orange LED powered by an orange wire;
it's current limiting resistor is red red brn gold = 220 Ohms, which is odd; if it were powered by the same supply as the others, this LED would appear to be very dim by comparison.

Below where you said:
"which in turn then power these small type leds things"
if you look carefully at the photo (heck, you have the item, look at it...) notice that on the right, the metal item inside the LED is wider, and the one on the left is narrow in comparison.
Then, look at how LEDs are constructed as in this photo:

Another image:

...and you will note that the cathode lead is the wider one. The cathode leads get the more negative voltage supply, the anode (the narrow lead) gets the more positive supply - unless there is something really odd about their construction.

Do you have a multimeter with a diode test function? If not, Harbor Freight Tools will sell you a cheapie in the neighborhood of $5.
Anyway, use the Diode Test function of the meter on the red LEDs. If I'm correct, the LED should glow when you have the black probe (plugged into meter common jack) on the right side of the LED (red wire) and red probe (plugged into meter V/Ohms/mA jack) on the left terminal, you should see it glow faintly.

Circuit 2:
Brown, red yellow green connects to two twisted pairs.
It looks like the green connects to white. Is the red connected to whites' brown mate?
This will be important to keep things sorted.

I am almost certain that those black rods are blacklights; as that's immediately what I thought of when I saw the glow inside the arm. The mystery is - what do they need in the way of power?
Here's a place that sells blacklights, but they dont' seem to have anything that small:
Or maybe they do? What length are those tubes, 6"? Look at this:
Looks like they could've bought a couple of those things, and wired the HV supplies remotely. It might be worth buying one of those just to see how closely the arm looks when it's lit up by that blacklight - or if you have a frend with a blacklight, see if you can borrow it.

More compact blacklight (and a bluelight) on this page; see the T5 shape; 6" long, 5/8" diameter:
Background on fluroescent bulbs including bulb sizes:

Circuit 3
"Black connector things"
There is one 5-pin black connector with six wires coming from it (brn, red, orn, brn, yel, brn)
There is one 6-pin black connector with four wires coming from it (wht, brn, brn, blk)
Without unplugging the connectors and using a meter, it's going to be tough trying to decide what's what. You don't want to pull that black insulation off if that can be avoided.
But, the red/brn, orn/brn, yel/brn came from the 5-pin black connector, and they are all brown wires to the DB-15 pin connector, which occupy pins 3 through 8.

Cascading marquee effect and static LEDs on the plastic -
can't tell much by that image from the top. There seems to be a lot of debris on the board and plastic. You might try using some canned air to blow that stuff off; it's going to look nasty under a blacklight or bluelight.
The marquee lights should have 5 wires going to them.
All of the resistors in view are 10 Ohms; except in the very bottom pic on the 1st page, you're pointing at a 1k Ohm (1,000 Ohms) resistor.

- Page 2 -

There is too much glare in the top pic to make any sense out of anything.

It's really tough to get good photos indoors. The best lighting you can get is outside on a cloudy day; it's very even and not harsh.

Circuit 4 - looks like there are 2 yellow and one white LEDs. I'm not sure what those rectangles are above the yellow LEDs.


Joined Nov 12, 2008
Yeah, that makes two of us. I hope this helps someone more experienced.

It kind of looks like a multiplexed display where six wires control 9 LEDs instead of using ten wires (with a common anode or cathode connection).

If that is the case, it appears this was indeed controlled via computer as Sgt. Wookie originally suspected. If true, then you'll either have to hook this portion of your prop to a microcontroller and program it to light the LEDs in the order you want or do the same directly from a computer. I know how to do the former, the latter not so much, but others here do I'm sure.

Thread Starter


Joined Aug 12, 2011
you guys are amaxzing.

Ok, i will get more pic of it outside.

I have a kane multimeter in the van which i am pretty sure has a diode tester, i will chekc this tomorrow for you guys aswell as more pics.

I am based in Scotland/UK.

So, your thinking it was probally powered, and controlled, by some pc using software i guess. I must confess, this is way over my head. I know electrics, but electronics baffles me, so your help so far is great!!!!!!!!! especially for a newcomer to the site like me.

Thread Starter


Joined Aug 12, 2011

its late, but couldnt wait so did as you said.

"Do you have a multimeter with a diode test function? If not, Harbor Freight Tools will sell you a cheapie in the neighborhood of $5.
Anyway, use the Diode Test function of the meter on the red LEDs. If I'm correct, the LED should glow when you have the black probe (plugged into meter common jack) on the right side of the LED (red wire) and red probe (plugged into meter V/Ohms/mA jack) on the left terminal, you should see it glow faintly"

It did glow, and got 1.704 dc on the meter. the yellow on the opposite side also glowed.

"Brown, red yellow green connects to two twisted pairs.
It looks like the green connects to white. Is the red connected to whites' brown mate?
This will be important to keep things sorted."

The green connects to the white which goes to the black light, off this is a brown which goes back to the yellow AND orange. the red goes to a black, which goes to the second black light, a brown goes back to the same yellow AND orange. the blacklights are 60mm long amd not much thicker than a pencil.

Circuit 4 - looks like there are 2 yellow and one white LEDs. I'm not sure what those rectangles are above the yellow LEDs. "

these are just small reflector discs for show, nothing electrical

More pics



Joined Mar 24, 2008
I use the black paint stuff all the time, it is liquid electrical tape (don't remember the exact name). You can buy it at the local hardware store.

You are in the right crowd. I suspect before you jump in too deep on trying to do something with this you will need to find a local electronics nerd time (we have lots of qualified people in the UK on this site).

You probably already know this, but don't trust someone just out of college or especially high school. Such types always think they know more than they do. Someone who has been doing it for 10 years or more will be a lot more cautious.

I'd jump in with the rest of the guys, but I'm up to my neck in projects at the moment.

A quick tutorial (which probably not be of much help)...

LEDs, 555s, Flashers, and Light Chasers

We've other folks (such as Fenris) make fandom Dr. Who props. The results were quite nice too.


Joined Nov 12, 2008
Here's circuit two. Can you draw something similar for circuits 3 & 4? On paper and taking a picture is fine. Your pictures are great, but the wires are just too close together to "see" what wires and colors are joined and going to what.



Joined Jul 17, 2007
Spent some time trying to track down the LEDs; found this on the side-emitting ones:

red - 2.2v@20mA Panasonic LN25RP - LNx5xx series
grn - 2.2v@20mA Panasonic LN35GP - LNx5xx series
yel - 2.2v@20mA Panasonic LN45YP - LNx5xx series

Datasheet attached - I named it for the green ones, but it contains them all in the last two pages.

These are obsolete LEDs; NOBODY has them in stock! That means if you burn them up, you'll pay a kings' ransom to find replacements - all the more reason to be plenty cautious.

The datasheet confirmed what I had deduced from the resistors in use and the combinations of LEDs; they all had the same Vf in the datasheet. The 220 Ohm resistor on the single yellow was a mistake by the effects person who built it! It should have been 43 Ohms.

If the Vf of those LEDs matches the minimum 2.2v that's in the datasheet, then Circuit 1 was powered by 3.0 volts. The Vf could be higher, and that would be OK - no risk of burning them out, as the current would simply be less. You should get about 18mA-18.7mA current through the LEDs with 3v in. The one with the 220 Ohm resistor will get less than 4mA current.

They may have operated the LEDs very "hot" (high current) to make them bright; these LEDs are quite dim by today's standards. You don't want to do that.