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.
this post was submitted on 25 Apr 2025
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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!
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.
His earlier videos are all about conductive ink
Ah, gotcha. I'll keep that in mind and double check his channel later this evening.
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.
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 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
Copper foil tape
Isn't that only good to block radio frequencies and other interference? Isn't the adhesive still an insulator?
Most copper tape i've seen has conductive adhesive
This is interesting and good to know. I'll try to keep this in mind whenever I get ready to set up shop to finish fixing it, I do have a couple busted phones around and should be able to find a section of copper tape in one of them. 👍
You'll have a bad time with used copper tape. Just like why it isn't advised to reuse any other kind of tape (duct, packaging, electrical)
Hey I hear you there.
I'm still game to give it a try though. Besides, whatever fix I end up going with, I'm still going to cover over that with brand new Kapton tape to protect it.
Worked well to fix my instrument panel in the dashboard of my old truck.
I'll keep that in mind for future experimental reference, but as of right now I don't have any handy.
Thanks for the advice though 👍
For sure! It was pretty cheap but Idk if it will do it for you when its all said and done. Good lick
What about heatsink thermal paste?
That's not conductive, that doesn't conduct electricity. At least not the kind I have around.
I know at least one kind that had a high degree of aluminium in it. But you also have cheaper kinds that dont have that.
You do make a good point, which I was already aware of though.
But you also just reminded me that I bought some new heatsink compound about 5 years ago and put it up somewhere in one of my parts bins.
I actually haven't tested the conductivity/resistance of the new compound yet, but whenever I find it, that's probably going to be the first thing I check.
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.