Repairing Broken Trace. Do It Myself Or Send It To A Pro?

A broken trace should be easy enough to repair on a standard type circuit board. Usually you can just jumper between two points. Make sure the board isn't cracked. There could be multiple broken traces.

If it's an SMT board, its probably best to get a pro to do it.
 
What's SMT and can you link me to either an article or a video showing how to jump a trace? Cheers.
 
Surface mounted technology - micro tracks (I didn't know the US used the term 'trace' - so thanks for that) Every componet is a teeny rectangular package that is stuck to the pcb and air jet soldered in place. Every component, though different is the same shape. An ordinary soldering iron tip is bigger than the component, let alone the solder tag. They are often very high density boards and while a paperclip wound around the soldering iron can sometimes fix them, I avoid them like the plague without a magnifying lens, special gear and a VERY stead hand. The PCB tracks can be 0.1mm thick - so the usual process of scraping off the green surface to reveal bright copper, then bridging the gap with a thin piece of wire and soldering each end is impossible. Jumping the break on a conventional board isn't too bad with good eyesight as the copper tracks are much, much wider. Doing it on SMT boards is awful, even for the experienced. If you need to look at a video, you won't be able to fix a SMT board. An ordinary board is far easier.

When you say a 'broken trace' - how broken, and how did it get broken? Flexing, physical damage, poor previous repair. They're not common as a fault, repairing these is usually because of damage. If you stick up a photo of the damaged area we can suggest how to do it, and what tools.
 
If you're talking about the apparent break on the track second from the bottom, that could easily be repaired by running a small wire between the two solder points on either side. I don't see any board cracks, so I wouldn't expect any others to be broken.

However, since you're asking the question, I'm going to assume that you don't have much experience with soldering electronic devices, so I would recommend you have a repair shop do it. Its a 5 minute job at most, probably done while you wait.
 
What's a repair shop? I live in Leicester. We don't have that kind of thing here. If something breaks we throw it away and buy a new thing.

J/K. there's one on Humberstone Road. About a mile and a half away, Although they probably won't be open until July now.

So what kind of wire should I use? Bear in mind there'll be a metal base plate pressing against it when the device (my 388) it's part of is reassembled.
 
As Rob said, one way is to try to scrape the coating off the trace, but I would probably just use something like 28 gauge hookup wire and solder between these two points. The insulation will keep from any possibility of shorting if there is a metal mounting plate. A fine, low wattage soldering iron is all that's needed. Make sure you tin both ends of the wire first so that you get a quick and secure solder joint without heating the traces too much.

If you've got any old broken electronic gear around, try practicing your technique on that first. Its a bit like measure twice/cut once!
 

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BTW, I feel for you folks in the UK with yet another national lockdown. I've been lucky enough that I can get out for necessary things, grocery trips etc, and playing at the local muni golf courses. I stay VERY socially distant...usually 25 yards from the fairway where all the good players are!
 
Yep - I agree this is doable - If you have a bit of mic cable - or even thin speaker cable, just take one bit the right length, expose a few mm of the copper each end - then tin the conductors with a hot iron and some solder. Then put the tinned end over the solder pad on the pub and apply the iron till the solder flows and keep it very still, remove the iron and when the solder solidifies, do the same to the other end. Blue tack, in a blob can be used to position the bit of wire touching the pad - because it will burn your fingers if they're too close. you want the least possible time with the iron on the wire and pad - so apply carefully and push down fairly hard. The solder will melt and flow and as soon as it happens, remove the heat. If you get really stuck - pop it in the post to me and I'll do it for you and send it back. I'm perfectly happy to do this for you rather than pay a shop to do it. I'm in Lowestoft.
 
One point I would consider in my decision is HOW was the trace broken? I wouldn't normally expect to find a broken trace on a circuitboard installed at a factory unless the equipment has been dropped or otherwise abused or mishandled. So if I found a broken trace, I would want to know whether there might be some components which are also bad. Did a chip short out, draw too much current, and burn the trace in two?

I believe that Talisman had a good idea in saying that you might be able to solder a jumper across the break if only one trace is involved. I have never tried to fix anything on a circuitboard; but I wonder if you might be able, at least for testing purposes, place a tiny drop of solder on the break so that it spans the break and rejoins the two parts of the trace. You would have to be careful not to join that trace to one nearby and create an unintended connection which might blow things "big time" in the rig. If I were going to try such a repair, I'd use a soldering iron with pistol trigger to dispense solder by squeezing the trigger. Carefully executed, I can envision how a person with sight might be able to "feather touch" the trigger and dispense a tiny drop of solder to join ONLY the two segments of the broken trace.

My idea here is that you could quickly find whether that broken trace is the only issue in your rig. If it doesn't function properly and you know for certain that you joined only the two segments of the broken trace, then you may well have some serious issue which would probably require attention of a pro - along with BIG BUCKS leaving your pocket! Have you priced bench labor and diagnostic testing of equipment recently? I haven't heard of anything of that nature going for much under $80 per hour with maybe a two-hour minimum! Of course, I hope you can join the trace yourself and that is all that is wrong with the unit; but I have to admit that I have doubts whether that will be the only problem. I have never encountered a broken trace unless the equipment has been abused or damaged by a component failure - often producing smoke for you.
 
It's a long and complicated story involving a new pair of headphones and me thinking the monitor buss was faulty (it wasn't, but I didn't know that at the time). The broken trace is entirely down to me reassembling the mixer section of my 388 with all the care and patience of an adolescent chimp.
 
For situations like this, I've had good luck using magnet wire (enameled) to jump broken traces. I find it makes it easier to do a tidy, reliable jump.
 
I just might do that if repairing it proves beyond my capabilities. Cheers Rob,

What's the best way to pack it?
 
This is about as good of an instance for a first repair as you're gonna get.

Sorry if I missed it already, but do you have a soldering iron, etc.? If you do but you've never used it, then definitely practice on something else, as others have mentioned, before you attempt it. It could be any piece of old junk you don't need anymore. Just crack it open and work on trying to solder wires to the connections.

Soldering is not that hard to get a hang of. Just takes a bit of practice.
 
Any particular diameter or weight?

Here it's usually sold in 3 spool kits at hobby shops (IIRC 22, 26, and 30 awg). I think 22 or 24 gauge would be the easiest to work with and have ample current carrying capacity. I find it's handy to have around the studio for sundry fixes (eg hardwiring switched microphones).
You could try to make your own tape head or guitar pickup with the leftovers :D
 
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Not a neat job by any stretch, but simply a piece of scrap tinned hookup wire across a copper trace that I hacksawed to make a simulated break. The green conformal coating will need to be scraped off down to clean copper on each side. Solid wire for the bridge would be easier than stranded. Use a good quality rosin core solder and don't heat too much or the trace could lift. Try to find some old boards to practice on if you can beforehand. This was a scrap board I've saved for parts to salvage. Not sure why the suggestion to use 'enameled' wire that you would need to scrape or sandpaper the enamel coating off and then tin (coat with solder) prior to soldering(?)
 

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Well, I tried and made a complete hash of it. Not only did I solder one end of the wire to the wrong terminal, but I also managed to join two neighboring terminals together with solder. I can't do it, I'm not going to try and, expect an email soon @rob aylestone
 
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