Does anyone have any advice on how to make homemade conductive paint to fix a cracked carbon trace in a game controller?
It's the trace going towards the mode button, so I'm pretty sure resistance won't exactly be critical over a ~3mm gap, as long as it recognizes when the plunger button is pressed down.
Just link out the broken trace with a thin wire. This is what the professionals do. The original traces are carbon to reduce manufacturing costs.
No, this isn't what the professionals do, especially not in an area of a board prone to flexing due to gamer rage.
I've literally used conductive paint before as a professional, because you simply cannot solder carbon traces.
I'm just no longer in the field often enough to have any reason to afford the stuff, so I was hoping for some advice to make something worthwhile as a spot or three of homemade conductive paint, not some random hack shit that'll wear out in 6 months.
I know someone suggested defoger repair but here's another same cost. https://www.digikey.com/en/product-highlight/m/mg-chemicals/carbon-conductive-pen
Look for the channel of Robert Murray-Smith. He has tons of videos on diy conductive ink.
Man, I got lost in a different world last night, watching his videos about 3D printing and gearboxes and stuff, good stuff 👍
But do you have any particular link where he covers conductive ink/paint? Most everything I'm seeing is all mechanical contraptions.
Graphite pencil?
Yeah, that was the first thing I tried, but the gap at the cracked spot itself has a bit of a ridge to it and I can't get enough of the graphite to properly fill in the gap without the controller basically ending up with a bunch of loose graphite powder.
And it definitely ain't a good idea to try to realign the crack, I've already super glued that in place, soldered all the broken copper traces, and got everything else working.
It will need to be some sort of paint that can bridge the gap and make contact.
I fixed my keyboard by taking a single wire strand and just taping it with a piece of clear tape. It's been working without any issues for more than a year xD
You can get conductive epoxy, but I think it's more expensive than a new controller. But maybe something like that, graphite or iron dust mixed in epoxy? That would most likely need some trial and error to get proper mixture.
I'm actually considering using a short piece of patch wire and tacking the ends down with Pepto Bismol, which is partly conductive and will dry similar to a paint, but I dunno if the acid in Pepto Bismol might cause any long term board damage, or if it'll even be conductive enough after it dries.
Right now I have a test sample card with a line of Pepto Bismol drying out to test with my multimeter later. However that experiment goes might just only add up to a curiosity though, I'm sure there's gotta be a better way to make more proper conductive paint, and I'm totally open to ideas.
If you have most of the equipment, why not get a soldering gun instead of using pepto bismol? Seems like a creative solution but I don't think it will hold up to vibrations or even regular use.
You can't solder to a carbon trace, this ain't the copper layer.
Update: Nope, Pepto Bismol is useless as any sort of substitute for conductive paint.
Yes, Pepto contains bismuth, a conductive metal. But it also contains some mild acid and whatever other ingredients too.
While still wet, it's lightly conductive, but once it dries, it's about as good as an insulator.
Automotive rear window defogger repair. It is like $20.
Now that's a hell of a thought, thanks!
It's not quite worth all that for this one-off tiny purpose though, but you're absolutely right, that's exactly the sort of thing that stuff would be perfect for!