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vintage DL1414 LED display replacement & suitable socket

TTL

Oct 24, 2013
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I'm looking to replace a malfunctioning DL1414 vintage red LED display for an Oberheim DMX drum machine from the 80s.
Apparently these display modules are no longer available, but the newer DLR1414 works as a replacement and I've found a dealer who has them.

1.jpg

(image source: MatrixSynth)


Here's my existing (malfunctioning) display modules:
20240606-123627_IMG_0139.jpg

20240606-123655_IMG_0140.jpg

20240606-123730_IMG_0142.jpg

20240606-141034_P6060012.jpg

20240606-140850_P6060002.jpg

20240606-140949_P6060008.jpg

I'll have to replace all four modules because the characters are slightly larger/have different characters from the original (besides I'm sure the other 40 year old display modules are all living on borrowed time and need to be replaced soon anyway).
I have a couple of questions:

1) The replacements I've found have a 'Z' designation (DLR1414 Z) -see photos, but I can't find any information explaining what this means. The Osram DLR1414 datasheet mentions nothing about the 'Z', so it might just be a production code or something. Are these the right type to get?

s-l1600.png (image source: eBay)

s-l16001.png
(image source: eBay)


The specs appear to be the same when comparing with the original DL1414 (the datasheet even says "DL1414 T" which is what my existing display modules are labelled as.

2) I read that these are highly sensitive for electrostatic discharge, so I'm worried about handling them when soldering back onto the PCB which is why I'm considering a socket. That would also ensure proper alignment between the four modules and if I'd need t replace them again it would be easy peasy. The pin spacing is 2.54 x 15.24mm (0.1" x 0.6")with a total of 48 pins (2 rows of 24 pins).

Screenshot 2024-06-06 at 15.39.51.png


But will I have enough room for a socket? Which solution would add least to the height?
A low profile IC socket? Low profile PCB receptables? Something else worth considering?
A rough and quick measurement tells me I have around 10mm between the surface of the PCB to the drum machine's enclosure. This means I have around 3.9mm additional room for a socket. I suppose I might have to cut the display modules' legs a little shorter.
 
Last edited:

Delta Prime

Jul 29, 2020
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besides I'm sure the other 40 year old display modules are all living on borrowed time and need to be replaced soon anyway).
Bubble LEDs very retro very popular they reproduce them. About a buck a piece get yourself a little low profile socket you're going to be making mistakes I believe therefore let's try to minimize that and if you do make a mistake you just pop another one in.
See Here
I'm sure you're familiar with Boolean logic.
Never mind "z"

1717690097397.png
 

TTL

Oct 24, 2013
195
Joined
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Messages
195
Thanks for clearing things up.The LED modules are on their way.
I've found out that there's no room for a socket (not even a low profile one), so I'll have to solder them carefully (taking care of temperature and alignment) directly on to the PCB.

Another concern is what I read about electrostatic sensitivity in the datasheet:

DLR1414_esd.png

I do have an antistatic work-mat and wrist-strap, and I noticed that there's a test-pin located on the PCB in question with a grounding mark on it which I assume means it's for grounding while soldering components to it, but my soldering iron has no means of grounding.

I was hoping it would be as simple as winding some un-insulated wire around barrel of the soldering iron and connecting that to ground, but apparently (checking for continuity) the tip is isolated from the barrel. Is it just a matter of tightly winding some wire around the tip itself, then attaching it to ground?
 

Delta Prime

Jul 29, 2020
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Your ESD concerns are valid.
Make, model,of your soldering iron please.
Are you in the United States?are you in Europe?
The ESD wrist strap is in reality there to protect you. They come with the one mega ohm resistor in series so it will dissipate the current charge built up of static electricity safety. The ground on your PCB should be connected directly to protective Earth or PE. It's all about potential difference. The anti-static work mat also contains a serious resistance of one mega ohm. My soldering stations are ESD safe Hakko along with Quick 3202, Metcal
I put my four wire Kelvin micro-milli- Ohm meter to work and from the soldering iron tip to PE (Protective Earth) at my homes service panel I get approximately 3 ohms & that meets specification of the quick , metcal and Hakko. And be safe when soldering,
She's not wearing a wrist strap.
And she has a high threshold for pain!
photo_1707286785373.png
 

TTL

Oct 24, 2013
195
Joined
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Messages
195
Your ESD concerns are valid.
Make, model,of your soldering iron please.
Are you in the United States?are you in Europe?

In Europe. Why?
The soldering iron is a Japanese "Goot" branded CS-20 (20W) I've had for years. It's no longer available as far as I know, but the Goot CS-21 appears to be more or less the same model. It only has a 2-pronged AC plug, so it's not grounded. And like I said earlier, the tip appears to be isolated from the metal shaft.
Is there a way I can safely use this soldering iron to mount the new LED modules, or is it essential I use something else? I'm only a hobbyist, which is why I haven't invested lots of money into a soldering station etc.
If there's no way around it, what do you recommend I get if I want to keep costs down?


The ESD wrist strap is in reality there to protect you. They come with the one mega ohm resistor in series so it will dissipate the current charge built up of static electricity safety.

You're right. My multimeter measures 1M Ohm.


The ground on your PCB should be connected directly to protective Earth or PE. It's all about potential difference. The anti-static work mat also contains a serious resistance of one mega ohm.

By connecting to "protective earth", does it it mean I can connect it all to the ground pin of a grounded AC socket in the house?
 
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