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I have a USB switch and I want to change it so I can have a external button and LEDs. This would make it possible to hide the switch somewhere and just have on the top of my desk a button with the LEDs to indicates the current output device.

The button part is not a problem as it seems I can remove the solder and solder some shunts to have it externally. Please correct me if I am wrong or there is a better way to achieve this result.

I want to do the same with the LEDs. However, the connectors are so small that I am afraid I will not be able to remove the solder or solder after some shunts to have another LED externally.

So I am here to ask help on how to proceed. Is the only option only to remove the solder from the LEDs? Can I solder another LED to the one already on the circuit?

Note: the voltage measured on the led terminals seems to be 2.6 V.

enter image description here

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  • \$\begingroup\$ If you connect a longer-wavelength LED in parallel, the current will prefer to go through that one. E.g. if the light is green, you could connect a red one in parallel and the red one will light up instead \$\endgroup\$ Commented Nov 3, 2022 at 16:31
  • \$\begingroup\$ don't forget that long wires may pick up too much RF interference ... wire an external switch in parallel with the existing switch ... glue photo-transistors to the LEDs ... add a small circuit to light external LEDs ... use power from the board \$\endgroup\$
    – jsotola
    Commented Nov 3, 2022 at 18:07

3 Answers 3

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Would a light pipe be an option? Then the LEDs could stay where they are.

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  • \$\begingroup\$ I have tough about using light pipe that by understanding are just optical fibers. Do you know how to attach them to the led, some special kind of glue or does it needs to even be directly connected? and also the bend radius of the fiber, do you have more information about it? \$\endgroup\$
    – Jose Rocha
    Commented Nov 4, 2022 at 7:59
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It's easy to move the button to somewhere else. Or you can just solder another switch in parallel - the functionality won't change. So you won't have to make excessive soldering work.

For the LEDs, why don't you consider optical fibres? Instead of horrible-looking wires optical fibres would look better IMHO.

Plus, don't bother with soldering tiny things if you don't have the soldering skills and equipment.

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  • \$\begingroup\$ I have tough about using optical fibers but I can't find enough information about how to attach the fiber to the led, some special kind of glue or does it needs to even be directly connected? and also the bend radius of the fiber, do you have more information about it? \$\endgroup\$
    – Jose Rocha
    Commented Nov 4, 2022 at 7:58
  • \$\begingroup\$ @JoseRocha good question. Yes, fibres don't like to be bended. For ordinary fibres the bend radius increases with fibre diameter. I remember something like a factor of 10 (e.g. 5-mm-dia fibre's bend radius cannot be smaller than 50mm). I can't verify this at the moment, I'll update the info if I find something. For mounting, I can see a sponge-like thing on your board. You can use them as a guide and then you can apply silicon or epoxy to secure them in place if you are lazy enough :) Plastic adapters for pipes/fibres to be glued to surface (PCB in your case) could be useful as well. \$\endgroup\$ Commented Nov 4, 2022 at 9:26
  • \$\begingroup\$ If I want to glue this pipes any type of glue like hot glue will do or does it need to be a special kind of glue? \$\endgroup\$
    – Jose Rocha
    Commented Nov 5, 2022 at 9:45
  • \$\begingroup\$ @JoseRocha Well, normally hot glue is suitable. But keep in mind that if the fibre is lengthy and thick, and if bending radius is high enough then the fibre will come off easily due to high stress during bending. Make sure that 1- Hot glue doesn't damage the fibre when it's hot (I don't know if it does but, just a concern), and 2- Make sure it doesn't leak between the LED and fibre. \$\endgroup\$ Commented Nov 5, 2022 at 19:37
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That is a tall order. You need a very fine soldering tip and swiftly heat both sides. As you are not experienced and the solder islands are very fragile and the LED is also glued in place, this is not advisable.

The next option is a special double-tip soldering iron that looks like pliers.

The third option is an SMS heatgun, but that also requires practice. Best get a specialist or experienced person, as you also need to solder the wires and make sure there is no mechanical stress on the solder. Good luck.

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  • \$\begingroup\$ LEDs are easily damaged if heated multiple times. A better idea might be to just remove them and get new ones. Though depending on LED current, there's a limit of how long wires you could attach from the board, since there will be a voltage drop. \$\endgroup\$
    – Lundin
    Commented Nov 4, 2022 at 7:56

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