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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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.
You're giving people shit about "professional" and "random hack shit" and you just tried to use Pepto-Bismal to anchor a piece of wire.
JFC.
I have over 25 years of professional electronics repair experience. This is my own device, so I'm game to think a little outside the box from time to time. You don't learn shit if you're not game to experiment from time to time.
Pepto Bismol contains bismuth, which like other metals, is conductive. There are videos online demonstrating people extracting the raw metal itself from Pepto. Plus the stuff dries sort of like a paint, so I figured it might be worth a try.
So I tried it, on a sample test card, so what? I didn't know what to expect but I lost absolutely nothing by trying it on a test card.
Results: It was partly conductive while still wet, but effectively lost all conductivity once it dried out.
What did I lose? About 5 minutes of my time to set up the test card experiment. What did I gain? Knowledge, about a thing I haven't seen tested anywhere before.
I wouldn't dare try such oddball things in a professional shop, I'd use the right materials. Just figured I'd test something random from around the house for shits and giggles. Woulda been funny if it actually worked, but oh well.
If I really want to do a quick fix, I'll slap down a piece of wire and piece of Kapton tape. But I would like to extend my knowledge to a better point where I don't need to buy a $20 bottle of conductive paint to fix a single spot where I only need like 2 or 3 drops of the stuff, just figured I'd try making something up at home.
But the people offering me alternate solutions are not answering my original question. I would like to learn homebrew ways to make conductive paint similar to what the manufacturers use, both for this project and possibly other future projects. I wasn't asking alternate ideas.
Did it ever cross your mind that maybe I'd like to be able to do repairs with materials more similar to what the manufacturer used rather than a lick-and-stick approach?
TL;DR - I'd never try such random experiments in a professional setting.
Sigh, I guess I'll go hit up YouTube, at least some other commenters have provided links to some valid and relevant resources.
It's 100% what professionals do to repair traces. Please don't spread misinformation.
Yup the wire is going to be more tolerant of flexing than the glue or a solder joint.
The crack is right next to the left analog stick, in a spot that will receive random pressure and mild board flexing while in use. Sure the plastic shell is still intact and all the supports are still there, but this particular spot is still a bit of a sensitive spot.
I'm all about the idea of a little piece of patch wire, but I want to actually adhere the patch wire to the trace with a conductive paint. I don't want to just tape a piece of wire on it, only to have the wire micro-sliding back and forth and just wearing more carbon off the board over time.
And soldering is completely out of the question, you can't solder to a carbon trace.
I'd fix the mechanical with epoxy and then use a small conducive screw tapped into the exoxy as a bridge.
While that idea sounds good on paper, the crack runs right by the edge of the button plunger, so the fix is gonna have to be about as flat as possible, and well adhered with conductive paint.
At least it didn't crack directly under the button traces themselves, but it's right next to it..
Standard pcb board is about .15mm .2mm flush mount screws are fairly common.
To be honest you are most likely better getting a new device.
Nah, no need for a new device, all the actual game controls actually work after I glued the crack and soldered bridge wires over all the broke copper traces.
The only button that doesn't work is the Mode button, which swaps the D-Pad and left analog. Its default mode is the normal mode you'd expect anyways, so fixing the Mode button is totally optional.
It's just a bit tempting to get the controller back 100% functional, but it's not terribly important.
I was kind of curious to dabble around and learn ways to make conductive paint at home, and use the controller as a first test try.
With all the proper tools and materials, I am a professional, capable of soldering traces about as thin as a human hair.
https://lemmy.world/post/9917691
And when it comes to carbon traces, we absolutely did use conductive paint to fix damaged traces. But now I'm more into automotive repair and just don't happen to have any conductive paint in my home electronics repair materials.
All I was wanting was a good homebrew solution to properly patch a ~3mm damaged section of carbon trace, not some hack solution that'll just end up wearing loose and having a bad connection within a few months of gameplay.
So I do not find your answer helpful nor professional.
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
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!
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.
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
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
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.