[sdiy] Covers / shroud for unused header pins?

[David Huss]

If the cables are long enough often a good solution is to provide a sort of strain relief that ensures that that even if there is significant vibration there is no pull on the cables.

If cables do become loose I would consider applying moderate amounts of hot glue in the right places. If you plan to 3D print something anyways you could probably create a part that holds in the connectors, covers the pins and provides strain relief at the same time.

As for 12V/5V LEDs: it is quite likely you can drive the 5V LEDs from the 12V board with the right value resistors in series. Whether that is worth the effort, I can't tell you.

On September 6, 2024 7:12:38 PM UTC, "James R. Coplin" <james at ticalun.net> wrote:
>Basically, the cabinet has two of these installed for LED control.
>
>https://www.ultimarc.com/output/led-and-output-controllers/pacled64/
>
>As you can see, they have two large headers of pins for the led controls and since I'm using 2 of them, there are a significant number of unused pins. I have to use 2 because some of the leds are 5v and some are 12v. The whole cabinet is filled with point to point, crimped on spade type connectors. Troubleshooting an intermittent ground connection pretty much requires having it on and poking around. Further, because the control panel takes a lot of physical use and vibration from button presses, disgruntled fist smashing, etc, things can come loose since the connection are friction not soldered. The spades do have insulation on them to try and prevent shorting but even so, I had a loose connection hit the pins at just the right angle that the inside spade connected across pins and blew out a board. I probably couldn't do it again if I tried but the way my luck goes, I don't want to find out and that's why I was looking for solutions.
>
>The corrugated cardboard suggestion seems like a really good one and I will probably try that or some foam core. I'll probably just end up 3d printing something or use terminal housings that match with the minimum number of empty terminals installed for it to grab. The ribbon cable type connectors would be great but they aren't meant to go right next to each other so probably wont work either.
>
>James
>
>Nathan Trites wrote on 9/6/2024 11:43 AM:
>- show quoted text -
>
>
>Nathan Trites wrote on 9/6/2024 11:43 AM:
>> I completely agree, opening and closing the case isn't the issue here - precaution is. Maneuvering and working with live circuits is an inherent part of diagnostics and repair, and depending on the device there are infinite ways to cause shorts during routine work.
>> 
>> Personally, I'm surprised there's 20 posts of advice in this thread and no one's asked exactly what kind of header/connectors James is working with! Since it's an old arcade cabinet, I'd assume a mix of edge connectors and molex? Immediate advice: put heat shrink over the spade terminal. Any bigger free floating connectors just use larger diameter heat shrink (1" etc) long enough so it doesn't make contact with other parts. If you need to easily remove and re-insulate, some kind of tape. Florian's initial advice is the right move for most friction connector types.
>> 
>> Think thru the scenarios:
>> 
>> If the header is always exposed and could be considered a design flaw or allowed to happen due to other design choices (e.g. you need to have various connectors unsecured in order to work on it), having a way to cover the headers when not in use makes perfect sense. I'd create a dummy connector of the same type (with crimps inserted if needed), and if the connector type doesn't have a cover or covered version available, fill the cable opening with silicone RTV or hot glue.
>> 
>> If they were left exposed in the course of repair and the risk of shorting is there again... If they're low voltage/current I'd probably just put blue painters tape over them until they're needed again, or some type of Kapton, PTFE, or electrical tape which all have other compromises. If they're higher voltage or current, secure the loose connector as best as possible so it doesn't pose any risk, or create a dummy connector for the exposed header and insulate the openings with hot glue or something. As above, cover any free connectors on cables with appropriately sized heat shrink.
>> 
>> Nathan
>> 
>> 
>> On Fri, Sep 6, 2024 at 10:23 AM Florian Anwander <fanwander at mnet-online.de <mailto:fanwander at mnet-online.de>> wrote:
>> 
>>     Hello
>> 
>>     Am 06.09.24 um 14:17 schrieb cheater cheater via Synth-diy:
>>>     i'm still confused as to how unplugging a thing from the wall is
>>>     too difficult 
>>     hmmm, when I am repairing a device and I have to do measurements
>>     or trimming, I will have to open and close the lid a hundred times
>>     to change settings on the frontpanel and then get back inside to
>>     continue my measurement. Of course I don't want to unplug or
>>     switch off the device, for each move of the lid...
>> 
>>     Florian
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