Repairing broken traces on a circuit board

hi there my name's Bruce rain from bronchus creations and in this video I'm going to be demonstrating how to repair a broken trace on a printed circuit board a little while ago I did a video on repairing and damaged or lifted pads on a printed circuit board and this was very well received so I thought I would continue this and show how to repair damaged traces now traces can get damaged in a number of ways they can just get damaged by accident you get a nick in the in the trace but I work primarily with vintage Macintosh computers and most of the trace damage I see is from corrosion caused by leaky electrolytic capacitors or leaky batteries or from poor storage you know maybe moisture gets onto them and now and they get corroded that way so firstly let's go over some of the things that you're going to need are you obviously going to need a soldering iron it doesn't need to be the best soldering iron out there but I would recommend a soldering station rather than just an all-in-one soldering iron you're going to need good quality no clean gel flux you're going to need a really good set of precision tweezers you're gonna want a blade I use a scalpel but like an exacto knife a really good sharp blade for scraping we're going to need some UV solder mask and we're going to want some solder of course we're going to need wire for the actual trace repair and then afterwards for cleaning you're going to want some isopropyl alcohol and some q-tips or cotton buds and you know probably a toothbrush as well oh and of course it's good to have a multimeter to check your work to make sure that you've restored continuity to the damaged trace a couple of other things you're going to need very good eyes and a steady hand now I've got a steady hand why eyes are terrible so I'm actually going to use a microscope now the microscope does two things first of all it helps me see what I'm doing very well but I've also I've got a camera connected up to it so I can demonstrate what I'm doing now these aren't cheap so you may not necessarily have one of these at your disposal but if your eyes are fairly good I mean you can easily use something like this a little magnifier illuminated magnifier that layer to get up close so you know that will suffice or some you know maybe some magnifying glass or something like that but for the purpose of this demonstration I'll be doing it with the microscope now all of these things I'm going to go through in more detail as we go and there are links in the description for where you can buy pretty much all these things with the exception of q-tips and toothbrushes because I imagine you probably know where to buy those from now the wire that I use is enameled wire it's the same sort of wire that you would use on a transformer or an electromagnet it has this enameled coating on it which means that it is insulated however that enamel coating comes off very easy with the heat of a soldering iron so what that means is that you if you're needing to run a trace over the board where it might actually come in contact with some you know sort of other metal that insulation is going to stop it from creating a short by accident but it is really easy to get that insulation off when you need to so these are three different thicknesses of wire that I use I've got the thick one up at the top the medium-sized one in the middle and the really thin run down the bottom so if I'm repairing a thin trace I would use a thin wire if I'm repairing a thick trace I would use a thick wire now keep in mind that a trace is a thin film of copper whereas these wires are actually round which means that there's quite a lot more conductivity in the in the wire then there isn't a trace if you're basing it on the actual diyanet diameter so you don't have to go out and find why that's the same thickness as the Trey so as I say I just generally work with these size wise and the thinner wire for the thinner traces thicker wife and the thicker traces doesn't have to be exact another thing you may need is solder wick and that's this braided copper wire that's actually got flux in it and it draws solder into it so you can actually use this to try and draw solder out and so we may end up using this later on in the video as well now if you have a look here you can see these are nice clean and tidy traces they're like green color you can see that these ones are all still clean and tidy and there's no real issue with those this particular board has suffered from some pretty bad battery corrosion now this is not actually going to be repaired I'm using this as a demonstration this board is pretty much beyond help so if when you're watching this video you think hey you've missed a repair there I'm not actually aiming to repair this I'm just using it as a demonstration so here's what you don't want to see when you're looking at a trace as you can see that the corrosion has actually taken the film off the top of this and expose the copper and in some instances here if i zoom right in you can see that the copper is completely gone and just left an empty channel here with no copper in it at all and that's obviously a trace that has to be repaired we've got to bridge that gap there so I'm going to actually use this one here as a demonstration so the first thing we need to do is scrape away any of the old corrosion and any of the old coating on top of the trace so that we expose nice clean shiny copper now I'm using here these Swan Morton surgical steel blades are the main reason I use them it's because they have a curved blade and I find them really good for scraping but as I say I mean it's not an essential thing but it's just that's what I like to use so let's start off now make sure we're InFocus might just see them out of smidge okay so just going to get my blade here and I'm just gonna scrape away and as you can see that as I scrape that gets brighter and that's as I take that corroded layer off the top and I'm revealing nice fresh copper underneath it's not oxidized so it's nice and clean and what we want to do is we want to expose enough of this copper so that we can get a decent amount of solder because the largest surface area that we have the more secure this repair will be if we just expose the tiny little bit of copper and just put a little teeny-weeny wire across there it's only going to be held on by a time a bit here but if we expose this whole area it means of that wires got a lot more to to stick to okay so that's that's basically prepared reasonably well the next thing we want to do is use our flux now as I say this is a no clean flux gel I use an antique one once again links down in the description but you don't necessarily have to go with the mtech one but as I say what you're looking for is a no clean gel flux there are plenty out there this is the sort of thing you're looking for and we basically just want to get that fairly liberally on top of that copper now we get our soldering on and we get a little bit of solder and what I'm looking to do is I'm looking to just tin that copper so what I'm wanting to do is just coat the copper with solder so just get this home here yeah let's do that so now we've got plenty of solder on that copper not too much but we've got enough to work with there so the next thing we need to do is grab our wire now for this one I am going to use my mid size wire I would be fine with the small stuff but the mid size wire is a little bit stronger so I'm going to use that one I'm just going to cut myself a length I've grabbed just a length of I don't know two or three inches something like that place it here hold it in place with the tweezers I'm going to put it right there and then I'm gonna get some I might put some more flux on this it never hurts to have a little bit more there then I'm going to grab a little bit of solder on the tip of my soldering iron it's like this there we go and then I'm going to hold this in place with my tweezers and [Music] melt that on there now that's fairly lumpy there but it has held quite well that is definitely on there no problem there so now we just need to sold on the other side so once again grab a little bit of solder on to the tip of my soldering iron and there we go and that sold it on there as well now it's a little bit lumpy if I wanted to clean that up I could just get a little bit more flux on to it here I know I'm going heavy on the flux but flux is a very important part of getting nice smooth solder joins so now you can see that with that flux they're applying a little bit of heat all of a sudden that's now looking super smooth so let's just get a little bit more focus on that so that's the wire there I'm just getting to nudge that with my my tweezers actually I'm just gonna cut the end off it now not that and there is our tres repair I want to check and make sure that it's all nice and secure so I'm going to zoom into it a little bit here so I get it in focus there we go and then I will just give this a nudge with tweezers and that's not moving okay so now we'll just clean it up get my little q-tip with a little bit of isopropyl alcohol in it I'm just going to wipe some of this goop off if you really want to go to town we can always just get a toothbrush with a bit of isopropyl on it give it a scrub and there if you have a look here's a nice clean tracer pair that end is stuck on well that end is stuck on well and we've restored continuity so that is it let's just do another one we've got one directly above it as you can see right there great big channel missing out there so once again we do our scraping I might just flip this around okay so that's scrape here expose that clean copper nice it's great here get any of that mask off and in any corrosion so I've got nice bright copper there once again we get our flux on there whoops and then we get solder first it's very important to get the solder on this first before you start putting the wire down it just makes the process a lot easier if you've already got solder in one location it's a lot easier than trying to get solder on both at the same time so here we go nice coating of solder on that copper once again we get our wire and put that in place okay then get a little bit of solder on the tip of my soldering iron grab my tweezers hold the wire in place oops we have to do is get one side done first there we go melt the solder onto it that's nice and secure now we can focus on the other side get a little bit more solder on the soldering iron yep hold that in place there we go okay then again just trim off the excess like that and if I want to get that really neat I mean look to be honest that one is fine as far as I'm concerned but I can always just put a little bit extra flux on there and just give it a quick brush created a bridge there don't want to do that there we go and once again we have nice secure why are held on there and we've repaired that trait I'll grab my little toothbrush here and I'll give it a little bit clean get all that flux of it and then you have it another tidy treasure pet now sometimes when you have a broken trace right near over there such as we do here the veer is that little hole there you may want to actually run the wire right through that hole to give it a little bit of extra strength so that's what I'm going to do in this instance I'm going to scrape this off and yes I am a well aware aware of the fact that there are broken traces just absolutely everywhere here but I am only demonstrating this one here so let's actually run it from this fear through to the other via so we're actually going to be essentially recreating this whole wire with a new wire let's do the process the same as before we do our scraping to start off with and then I get a bit of flux on here I get my solder and get that melted onto the copper okay now I need this hole open so I'm gonna grab some solder wick which I referred to at the beginning and this is going to just take away any of that excess sold up from that hole so leave it exposed so there we go yes now there's our trace all ready for a repair sorry about the focus folks and I'm gonna grab my wire I'm going to poke one end through this hole I'm gonna try and get enough of it poking through there we go that's through on that slide and I'm just gonna bend that down that and let's solve that in so get out slowly yeah there we go just grab my tweezers so I can hold this wire in position there we go that's in pretty good now we don't really need to run the we don't really need to actually attach it to any of the copper along here because we're essentially completely replacing it I'm just going to cut off some of the excess of this wire so I can feed the other side through the hole there we go let's poke that through I'm probably easier for me to pull this from the other side so I'm going to whip him around yeah let's pull that through and here's our other one let's flip them back over to the other side here we can see it's our wire it's gonna Bend that to kind of match the contour of the original trace I do that purely for neatness no other reason at all and once again we get some solder and we paint that up there we go all right I might put a little bit more on this side as well okay so now rather than actually yeah soldering it onto all of these little bits of copper in the middle we're just doing it from end to end and then we're gonna flip him over to the other side and I want to actually carry that on carry that repair on to the copper underneath so I'm going to scrape a little way here once again get some solder onto that copper then grab my tweezers this is a lot easier to manage now because it's secured well on the other side grab two tweezers here so they're like it once again bend this to the contour of the original trace just so it looks pretty I could definitely using a much thinner wire than this okay hold him down there we go that's cut off the excess and that's one end all done and where's the other end to the other end you use over here once again let's scrape that get some soda get some solder onto the copper and bend the wire kind of Farex this once again and there we are so let's zoom out a little bit here can we see both of them we've got that's going along there through the hole along the trace on the other side out here and then attached to there so give that a quick little cleanup toothbrush and let's have a look on the other side I'm just gonna I just want this to be a nice blob on this side even though I know it's sold them from the other side I just prefer the look of it if that's got a nice blob on it like that here's a blob and then we'll just clean that up as well yes we can there we go one tidy little trace repair joining up between those two veers so the next thing we want to do is we want to make sure that those repairs are well protected so first of all we need to get them nice and clean make sure any flux is gone now I would typically clean it in ultrasonic cleaner if you don't have an ultrasonic cleaner you can just do what we've been doing here with a toothbrush and some isopropyl alcohol and just try and get all of the flux and gunk off so that you've got a nice clean surface and then we're going to paint on some UV solder mask to help protect the repair okay so i've cleaned this as best as i can obviously it's still horrendously awful but that's more to do with the fact that this board is an absolute train wreck and now what I'm going to do is I'm going to take my UV solder mask it's like a sort of a plastic substance that hardens when exposed to UV light it's it comes in a syringe like this as a liquid and you can just paint it on I'm just using a little little paintbrush here very fine tipped paint brush and so if we just grab some of this UV solder mask and we just paint it over the top of our trace you hear this this builds like a little buttress on either side of that repair to help give it some strength just get that pine to die over there you know okay so the next thing we need to do is we need to expose this to UV light in order to get it to cure now I have a UV globe here but I'm in the middle of summer in Sydney so I have got quite a big UV globe outside so I'm going to just take this board out into the Sun and let it sit and it takes a few minutes in the Sun and that will be rock solid okay so this UV solder mask has now had a chance to dry and this is now quite quite tough it's quite a hard and sort of plastic and that repair is not going to come apart at any time in the foreseeable future I do hope this video has been of some help and thanks for watching you

Channel: Branchus Creations

Views: 576,607

Keywords: soldering, Macintosh, recapping, vintage, capacitors, surface-mount, surface mount, computer repair, vintage mac, diy, surface mount components, old computer, electronics, electronics repair, Apple, Re-capping, recap, replacing capacitors, Motorola, Compact Mac, repair, SMD, apple, mac, broken, trace, broken trace, trace repair, soldering iron, how to solder, solder, circuit board repair, pcb repair, how to solder circuit boards

Id: ref9JHUf-uw

Length: 23min 49sec (1429 seconds)

Published: Mon Dec 30 2019