PCB Component Repairs

Yeah, I was pretty proud of that find. :slight_smile:

Like I said above, I’d give it good odds that by replacing those burned parts it could spring back to life. It will be a ‘little’ bit tricky because they’re surface mount components, but they’re pretty large so shouldn’t be too daunting to work with.

Bare minimum equipment list would be:
Temperature controlled soldering iron
Tweezers
Decent solder wick
Solder
Thermal paste

Some nice-to-haves that could make it easier:
Flux
Isopropyl Alcohol and some cotton buds
Some form of magnifier, ideally wide-field and long working distance.
Adjustable bench power supply for testing.

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Given it’s age - If you’re able to identify and replace the obviously blown U12 and D15 (I’d check the discolored D14 as well), I’d highly recommend replacing the 4 aluminum electrolytic capacitors that are at/near their end-of-life. They’re the 4 large(er) brown tubular components - three mounted on their sides, one vertical. They can be purchased (at increasing price) with 2K to 20K hours expected lifetime at rated specs, and as such are often a candidate for “cost optimization”. A failure of one may well be the root cause of the blown components. I’ve seen it many times in a wide rance of circuitry - especially in the power supply sections, as yours are. They’re relatively inexpensive, and the price difference between the 2K & 20K is minimal.

  • Al
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That’s always my concern, are the blown components the cause or a symptom. You high 5 yourself getting new ones on there and first time you apply power they pop again because it was something else

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You aren’t alone. :smile:

Plus, the word Nichicon makes me want to suggest that as well.

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I’m sitting staring at it at the moment - trying to track down someone local with board soldering/making experience before I botch it entirely! THEN I’ll worry about the next step!

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If you get stuck, the offer is always open to just send it over the ditch and I’ll take a stab at it. PM me any time :slight_smile:

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You two can also just meet halfway at my place. :stuck_out_tongue:

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I didn’t realise you lived in the middle of the Tasman sea…

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You are from NZ?

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Yep, sure am! :slight_smile:

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Then scratch that. :stuck_out_tongue:

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I guess if @jono035 went East and I went West you would be pretty much dead in the middle! :smiley:

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Here’s where I am at.

I “think” I can bumble through the diagnosis stuff.

I contacted our local “repair cafe” to see if there was an electronics wizard on the team, (I’m still not sure) and ended up being invited to come for a trial shift next Saturday. :rofl:

I’ve been practicing soldering before I pull anything apart, and it’s one of those cart/horse things - I’m probably not going to get good enough without the proper equipment, but I don’t really want to get the proper equipment until I’m good enough. I can connect stuff to other stuff OK, but I’m really a long way off soldering a board, and can’t see that learning curve getting any shallower any time soon.

So I’ve been corresponding with @jono035 and my board is on its way to a holiday in the Shaky Isles. I am incredibly grateful for his offer, and just a little bit excited at how cool this really is!

Many thanks to all who have commented too - you’ve all given me a lot of inspiration, to say nothing of just a little more of an understanding of all of this. I am really looking forward to seeing what happens next.

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Keep at it with the soldering. It’s hard to overstate how much good equipment helps, especially when you’re learning. It’s the same as most things, I guess… An expert can create a good weld even with a cheap crappy welder, but a newbie needs all the help they can get.

Always happy to help with anyone trying to learn to solder as well. There are a bunch of tricks that can help make life easier etc.

Looking forward to having a look at this thing. I’ll take some notes as I go and update on the troubleshooting process etc.

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Absolutely. I was lucky enough to work at a place with a good electronics lab, but not good enough they wouldn’t let me use it.

Small solder, fine tip, temperature controlled all helped. But the best tool was the microscope they used to solder. I was amazed at how much better my hands were when I had excellent, low latency vision. My eyes are pretty good, but 10x magnification really helped on surface mount 603 components.

I’ve tried to replicate that at home for a lot less and it is 90% as good.

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Yeah, the magnification is a good point. My eyes are still good enough that I find magnification unnecessarily cumbersome for most soldering tasks but it really helps for inspection and QC, especially for fine pitch leaded components where you’ll always end up with a solder bridge or two while hand soldering.

These days I do any assembly with more than about 20 components with a stencil, paste and reflow though just because it’s so much faster and has a higher quality result.

We’re currently going back and forth on what to do with my latest board at work. It’s either a production run of 20 boards via an external contract assembler or hand build 2-3 of them for in-house testing first. Originally it was looking like timelines were going to push us to getting 20 of them externally, which I don’t like doing as a first pass on an all-new design. On the other hand, it now looks like budgetary concerns are pushing us to hand assemble a few first, which I also don’t like doing when it’s a 256 ball fine pitch BGA and a couple thousand passives. That’s going to be a crappy day.

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Can we start with basic soldering iron, solder and flux?

The internet is awash with tiny cheap usb rechargeable models, they are temperature controlled, but how do I know what temperature to use?

Currently I have a Ryobi One+ which is great for joining bits of plumbing and car parts, and was a revelation compared to my el-cheapo Wellers that I bought fifty years ago.

I’ve only briefly had a look at the Ryobi iron. It seemed surprisingly good for what it is, but I’d have said that it’s a little bit too much of a brute force blunt instrument for some electronics tasks. I’m surprised that you found it significantly better than an old Weller, though… I’d have thought they’d be reasonably similar, performance wise at a worst case, or that the Weller would have the edge. Some of that might come down to old/ruined tips, perhaps?

The tricky part of all of this is that it comes down to what you’re trying to do. Joining a couple of wires together or doing through-hole stuff, honestly the One+ iron is fine. That and some solder and you’re away.

As the complexity of what you’re trying to do goes up, the size of things drops which means you need smaller and more precise tools, as well as a bit of extra dexterity thrown in.

If you’re asking for some suggestions:

That changes for what your goal is, whether it’s more focused on through-hole stuff, surface mount stuff, how complex the surface mount stuff is, mostly assembly, mostly repair/rework, etc.

As a starting point for a mix of assembly/rework (because let’s face it, most DIY/hobbyist stuff of any complexity level is going to be mostly repair/rework because it aint gonna work first time!) of moderate complexity surface mount stuff (0603-0805 components, SOIC/TQFP ICs), I’d start with what’s below. I’ve tried to add some links to show the specific products at one of the suppliers we use often but that’s more just because it’s a good one-stop shop and shows details, not because I think they’re a good place to buy from unless you’re in NZ:

Requirements:
A good temperature controlled soldering iron
An appropriately sized soldering iron tip
Wire-wool type tip cleaner
Solder
Solder wick
Tweezers

Strongly recommended:
Flux
Magnifier
Some kind of fine pointed hooks/picks
Extraction
Isopropyl Alcohol
Cotton buds

Nice to have:
Scalpel
Tip tinning compound
Swivel vice or 3rd hand
Good lighting
Anti-static mat/strap

Soldering Iron

The soldering iron topic is something where I could spend hours writing a thesis on it. Fundamentally, the job of the iron is to heat stuff up quickly and precisely so you can melt solder onto it. You want something where you can adjust the temperature and be confident that it’s correct, because too cold doesn’t flow well and too hot will damage stuff. You want it to be well designed so that it has good thermal response, basically so it doesn’t immediately crash in temperature when poked into a cold object. You want it to have a decent variety of tip styles because there are always trade-offs with different styles so you can get one that suits the task at hand.

When it comes to irons there are 2 common tip designs. The older/simpler/cheaper one is the type that has a separate heater element and then the tip slips on over the element. That’s how the Weller stations you had likely worked. These are great because the tips are cheap/plentiful and essentially disposable. The downside is that they tend to have less power, worse temperature accuracy and MUCH worse thermal response so they’re slower and harder to use. The newer/better solution is to have an all-in-one tip that integrates the heater and tip together. These have a much better connection between heater, temperature measurement and tip so you get better accuracy, faster response and much more output power. Plenty of people get by with the cheap type but after using the all-in-one type, I really prefer the more modern approach.

Technically speaking there are also another type which are the RF irons where they use fancy tips that instantly change impedance vs temperature so you get the fastest response possible but I haven’t seen any that are in a DIY $ range. They used to be insanely better than the separate heater/tip types so were worth the money but with better modern iron/tip designs I don’t notice the difference as much anymore. I wouldn’t bother with these, even if you can find a good 2nd hand deal simply because the tips are so much more expensive.

For power I typically just ignore that. For small stuff and being careful, any amount of power is fine. For big stuff or moving super fast I think it’s more important to have an appropriately sized tip and potentially even just an entirely different iron. We have a separate big station for large stuff and often you’re better off pre-heating a board anyway.

When it comes to brand, I’m very fond of the Hakko irons. I use Hakko FX-950 and FX-951 stations both at home and at work. They’re not cheap (~NZ$600) but can sometimes be found 2nd hand. There are also some knock-offs around that may be good enough but I’m not familiar with them.

Fundamentally anything that’s designed similarly is likely to be decent enough. The requirements of the iron are actually pretty basic, as long as the design is good then the implementation itself isn’t super important, I don’t think.

Alternatively, there are a few interesting options like the USB powered irons such as the TS80, TS100, TS101, Pinecil, HS-02 etc. In general I’m slightly suspicious of these, they all claim good power figures and relatively fast heat times. They’re all temperature controlled. They all seem to use the integrated heater/sensor/tip cartridges which is nice. I’m less convinced by the ergonomics and user interface.

I picked up a TS101 to have a play with but I’ve only used it for heat-set inserts so far. It didn’t like any of the USB power supplies I had and only works with an external power supply or the horrifyingly expensive USB battery bank that I bought for my Steam Deck, so I’d factor that in. The tip is a long way away from the handle which isn’t good ergonomics, it’s significantly bulkier than the pencil from the Hakko station and the UI is infuriating. Other than that it seems like the performance should be ok.

I honestly don’t know that I can give a truly reliable set of recommendations here. At NZ$100 the TS-101 seems like it’s probably the best option. Cheaper than that is probably a TS80 or getting too sketchy for my tastes. At NZ$200-300 then a 2nd hand decent brand station and some new tips is getting possible. At NZ$600 I’d get an FX-950, 3-4 tips and then have that as the only iron I’d ever need.

Soldering iron tips

This is something where I disagree with Jeff a bit. I always try to use the largest tip I can get away with. I actually hate fine tips and think they’re misleading. The problem with them is that they’re too thin and have too little surface area, so they don’t get good thermal transfer to the joint you’re creating. The tip that I use for 90% of my soldering is a Hakko T12-D12. This is a 1.2mm chisel tip. It’s fine enough that you can solder individual pins on a TQFP if you’re careful but still large enough that it can be used on pins with direct connection to a copper plane or the tab of a power package like a D2PAK etc. I also use a T12-D4 tip which is a 4mm chisel tip. Those 2 tips are 99% of my soldering. I have a pretty huge range of others like the T12-I which is a super fine 0.2mm point, 9.5mm long tip. I essentially never use this unless I absolutely have to because the thermal performance is so compromised. I have a T12-B which is an intermediate 0.2mm 5mm long conical tip but I find that to be a poor compromise between both.

Regardless, make sure you purchase an iron where you can get a range of tips and easily source a replacement. If the tip is good quality and well cared for it will last thousands of hours of use. I think my one at home is still original and I’ve had it for 15 years, many hundreds of hours use and maybe 1-1.5kg of solder?

It’s a good idea to have a ‘throwaway’ tip or iron floating around so you’re not tempted to use the good tip for heat-set inserts, melting stuff, etc.

For keeping the tip in good condition I like using a tip cleaner paste if I notice it’s not wetting out evenly anymore. They’re pretty cheap and if they extend the life of a single tip by a little bit then they’ve paid for themselves.

To keep the tips in service for as long as possible, I like to give them a good few passes through the wire wool tip cleaner after use then apply some solder directly to them until it’s a bit of a blob, then turn off the iron. Keep them clean, any time they stop wetting out nicely or start looking cruddy, stop and clean them with the wire wool and re-tin them. Don’t let them get bent or physically damaged and they’ll last ages. Don’t ever file/sand them. The outside coating is critically important and if it gets broken/abraded off then the material underneath will dissolve into the solder and you’ll have a tip lifetime measured in hours, not years.

Soldering Iron Tip Cleaner

DO NOT USE WET SPONGES. Just don’t. Get yourself a wire wool type tip cleaner. These scrape excess solder/flux/whatever off the tip gently without abrading the plated surface. Use these often as you go, even after every joint if you’re struggling. It should be a quick motion of stabbing the tip in, pushing it down slightly, pulling it out, rotating the tip a bit and then doing it again. You should end up with a fresh looking tip without excess solder on it. If the tip isn’t in good condition after doing this, stop and re-tin/clean the tip more carefully. If you end up with too much solder on the tip, swipe it off into the coiled wire and go again. You can get refill packs but honestly I think I’ve replaced mine at home maybe twice in the past decade. They last.

Solder

I’d always recommend leaded solder for starting out. The alloy matters less than it being a leaded solder. It has a lower melting point and oxidizes slower so it’s much more forgiving. It’s also pretty safe to work with in solid form. Ventilation is a good idea regardless of solder used because the flux fumes get pretty nasty. 60/40 is the ‘standard’, 63/37 is also common, some types advertise as having a couple of % of silver and are slightly better in theory but I don’t know that it’s enough for me to notice it. I tend to notice the quality of the flux much more than the alloy, I believe.

For solder sizes, it’s kind of a personal preference thing but I would say to start on the finer side, something like 0.5-0.7mm. They tend to have more flux relative to the volume of solder which leaves more residue but makes for a cleaner/easier joint under non-ideal circumstances. There’s also just less of it per cm so it makes feeding the correct amount of solder into a joint much easier. The only real downside is that it’s a little bit slower, a little bit messier due to having more flux residue and can be annoying to manage. If you’ve got the budget, getting 2 sizes is nice. The second size being ~0.9-1.2mm will mean less stuffing around with the solder when you’re doing through-hole or larger parts.

I would also say to stick to common brands of stuff and ideally from a reputable supplier. I’ve bought some soldering consumables via AliExpress and have also tried to use stuff that my Dad bought from there as well. It’s noticeably crappier. Solder that isn’t the alloy it claims to be, seems to have either no or expired flux, solder wick that may not actually even be copper, etc. Good consumables make all the difference. I can get by with crap consumables and figure out how to use them, but it’s SO much harder. I think all the stuff we have here is Multicore/Loctite, Stannol and maybe some Goot stuff. Looks like you can get 250gm rolls of Loctite 60/40 so that’s a great starting option.

For quantity, the most common sizes are 500gm rolls which is enough for thousands of boards. I think I’ve gone through maybe 2-3 of those in my entire career? I wouldn’t go for the tiny little coils you sometimes see but anything in the 50gm+ range is likely to be tons.

Solder Wick

This is my primary method to remove excess solder from a joint or clean a board of solder after removing a component. I like the Chemtronics branded stuff as it has good flux and wicks nicely. We have some Goot stuff that’s ok. Cheap/crappy stuff won’t wick and will be a nightmare. Having a couple of sizes is a good idea, small stuff is frustrating for large pads, large stuff is unwieldy on small pads. Ideally I’d have a small size like 1mm and then a larger size of 2-3mm, perhaps with a 1.5mm additionally. You can get these on smaller bobbins pretty cheaply which is what I would do and then just re-buy as needed. Don’t spend up big on a 20m bobbin because it’s ‘value for money’, chances are it’ll be a size you’ll never like using.

Tweezers

There’s no real hard-and-fast rules here, just something that lets you reliably hold a passive component without getting in the way but isn’t so sharp that it’s dangerous or too flexible. It’s not a bad idea to have a few different options. I don’t like ones that come to a complete sharp point, I prefer a fine but flat tip. You can get them hooked or straight, I prefer the straight ones because they’re usable through a wider range of motion/angle, but that’s just down to personal ergonomics. I like the Wiha ESD safe range, specifically the 2 SA ESD (listed as reduced body medium point in the catalog) but you can get cheap stainless steel Goot knock-offs that are good. ESD safe is nice but not necessary. Obviously nothing plastic.

Flux

It’s nice to have and is a great ‘go to’ if you’re struggling to get something to wet out nicely. I would recommend a gel style flux in a syringe for ease of use. You may need to separately buy a needle for it. I think the MG Chemicals ‘no clean’ flux gel is what I have at home. No clean just means that the residue it leaves is mostly inert and won’t corrode things long term. It’s still a good idea to give things a bit of a clean if you’ve used a bit of it.

Magnifier

Whatever works for you, really. It should be comfortable to work at for a long period of time, ideally with a wide field of view and long relief. 6-10x magnification is plenty. I have a binocular microscope at home that works well but it’s finnicky to work under because of the narrow field of view so I wouldn’t recommend it unless you’ve already got one. At work we use a Mantis viewer which is great but horrifically expensive. I think they do come up 2nd hand. Some people like using loupes, others like using the visor type magnifiers. In the past I’ve used the ones that are just a big magnifying glass lens on an arm but I wasn’t really a huge fan of that.

Hooks/Picks/Scalpels

Again, whatever works. Old dental tools are great choices and you can sometimes just ask a dentist for them as they replace them super often before they wear out. We have some stainless steel picks that are meant for the purpose. They’re great for prying up pins, poking away solder balls etc. There are also cheap sets of PCB rework/repair tools that can be useful. Having the little knife/chisel point probes is the most useful for cutting traces or scraping solder mask off. I don’t find the brushes useful at all. A scalpel can be a nice addition, too, although they’re a bit less robust than I’d like for cutting copper traces etc. so be careful.

Extraction

I use a free standing extractor at home because my office doesn’t have much airflow and I need something with good performance. There are a TON of options, though, ranging from 3D printed DIY things with a fan and basic filter cloth through to hardcore fume hood/external vent setups. The commercial desktop filter+fan units are by far the most common in my experience and can be had at a range of prices. Anything here should be fine but it’s worth considering that cheaper units may not have the same level of filtration. It’s not just particles, it’s gases that can be the concern. Or just keep a window open and some fresh air flowing in, honestly. Try not to hunch over the board and keep your face back, getting a plume of flux smoke in your eye sucks pretty bad.

Isopropyl Alcohol/Cotton Buds

Used for cleaning parts post soldering. After removing a component and wicking the excess solder off the pads, the board will be pretty manky. It’s a good idea to give things a clean as you go while it’s still warm with an IPA soaked cotton bud. This can be just whatever but I quite like the ‘pump top’ bottles and the longer electronics technicians cotton buds with wood/bamboo sticks. I think ours are Chemtronics brand. You can break the cotton bud in half to use as a mildly abrasive scraper for removing really stubborn stuff, too. Whatever works, in this case. You can also use brass/nylon brushes but I find the brass scratches the board and both get sticky/manky after a while. Some lint-free wipes can be a good idea, too, but I typically cut them down into ~50mm squares. They can be wrapped around the tweezers and used as a more aggressive swab/wipe.

The rest is all just kinda ‘you might find this useful’ type stuff.

For the anti-static mat/band, I don’t bother with the bands anymore but I do use a decent heat-resistant 3M anti-static mat that is connected back to the building’s main earth. Pretty much any cheap mat here will be fine but the more expensive ones won’t immediately melt if they get a blob of solder on them or a dropped soldering iron. It’s worth double checking that they are actually static dissipative by using a multimeter to measure resistance between the metal case of an earthed appliance and a large coin sitting on top of the mat and pressed in hard by hand. It should read in the 10s of MOhm range to the top and in the 1-10 MOhm range to the back side. The wire that connects the mat back to earth should have a 1MOhm resistor in it already.

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As for general process/tips and tricks…

Soldering iron setup

I would start by making sure that the soldering iron tip is mostly clean and appropriately sized. Get the iron on and heated up to ~300°C for leaded solder or 350°C for lead free. Melt some solder wire onto the iron tip directly and then swipe the iron through the cleaning wire coil a few times. Inspect it to make sure it’s clean/shiny and then you can start.

Those temperatures are on the lower side so if you’re struggling you can raise them. That will cause the solder to flow easier and will allow easier heating of large/cold parts but at the expense of needing to be faster moving to avoid overheating components or the board itself. With time you’ll develop a feel for what’s acceptable or not. You can also significantly lower the temperature if you’ve got a good sized tip on your iron and can get heat into the component quickly.

General soldering technique

The general technique is to use the tip of the iron to heat whatever you’re trying to solder and then, once hot, dabbing solder wire into it until the correct amount has been applied and the solder is clearly covering the entire pad while flowing up onto the pin you’re connecting to. Ideally this should be a tiny amount of force, pretty much just resting the iron on the pad, trying to use the widest part of the iron tip that’s reasonable, waiting for 2-3 seconds then one dab of solder to get to the correct amount. That all comes with practice so to start with several smaller dabs and waiting a few seconds more isn’t going to hurt anything. Each joint shouldn’t take more than about 10 seconds though or something’s not quite right.

Soldering passives

For soldering down small surface mount resistors/capacitors, I like to heat one of the pads with the iron and dab a tiny bit of solder on first, then remove the iron. I then pick up the passive with tweezers and position it in place, pressing down lightly. Apply the iron to both the soldered pad and the passive’s terminal until the solder flows then remove the iron while continuing to hold the passive in place for another 1-2 seconds. If the passive doesn’t look like it’s sitting flat I’ll come back and press down on the top lightly with the tweezers and re-heat the joint again so that it sinks down onto the board fully. Then solder the other terminal. If you end up with ‘spikes’ of solder coming off rather than a nice round blob it probably means that some oxides formed because the joint took too long and there isn’t enough flux left. Adding a little bit more solder can make the joint round and shiny again. Ultimately you’re looking for a smooth curved fillet of solder from the pad up to the terminals. If there are sides that don’t have a fillet at all, that’s likely not enough solder or not enough heat. If there’s a blob or ball then that’s too much. I wouldn’t worry about it as long as it’s clearly connected, but it’s a sign to try use a little less next time.

Soldering ICs

Same as above, pretty much, but I’ll start by tinning a single pad. It doesn’t matter which but I would typically use one that will melt easily, so not one that has a thick trace coming into it. Grab the IC by the body, hold it in place, flow the solder with the iron, remove the iron, wait a second for it to cool, let go of the IC. If it’s not quite in the right position but close you can prod it into place which will bend the lead very slightly. If it’s well out of position, grab it again and reflow the joint while moving it. Once it’s in place I would choose a pin on the opposite side/corner of the part and solder that pin to lock everything in place. Once that’s done I would work along each pin one by one. When soldering the pins you’re trying to get both the pad and the pin hot together, so either put the iron tip on the top of the pin and press it lightly into the pad, or put the iron tip alongside the pin and pad together. You’re looking for a smooth fillet of solder up all 4 sides of the pin. As with the passive if there isn’t a smooth fillet there might not be enough solder, if there’s a big blob there might be too much. Sometimes you’ll get too much solder and it’ll create a ‘bridge’ across to adjacent pins. I would just move on, finish all the soldering then come back. Sometimes this can be fixed by heating the bridge and dragging the iron away from the pins, pulling the solder out of the bridge. If that doesn’t work, add a little bit of flux and re-heat, that may cause the solder to flow to the 2 pins and break the bridge. If there’s way too much solder then that’s when I’d get out the 1mm solder wick and try to remove a little bit.

Soldering through-holes

For this I just put the component through the hole, stab the iron tip into the pin and pad together, wait a few seconds and then start dabbing solder wire into it. I would aim to wait for long enough such that when you apply the solder it immediately runs right around the pin and covers the pad. I wait a few seconds on each joint and you should see the solder level drop slightly as the solder is wicked up the pin and into the void of the through-hole. If the end joint looks a little flat after this, I’d add another dab of solder until you’ve got a nice curved fillet. Again if there’s a blob of solder at the end it’s no big deal but I’d aim to do less next time. If you can see the top side of the through-hole, like with a DIP component and most connectors, you can check to see if solder has come through to the top side. The ideal is to have the through-hole completely full of solder but without it running out of the component side of the board or climbing up the pin to the component. It’s a good idea to get a feel for when this has happened without needing to check the top side because some components like capacitors often don’t let you see the top side of the board.

Removing Components

Removing components is a bit trickier and there are a ton of approaches.

For passives you can try heating both sides one after the other until the part moves. You can add a lot of solder to bridge over the part and heat both at the same time. If you’re really stuck you can ‘clip’ the part in half using a pair of side cutters.

For ICs, it depends a lot on the size of the IC. For smaller SOICs you can usually blob solder across all the pins on both sides of the IC and then heat them in turn until the IC is free to move. For much larger ICs like TQFPs etc. then you can do something similar with a loop of wire or used solder braid. The goal is to spread heat to all of the pins at once. Don’t worry about using excess solder, it can be cleaned off later. Alternatively if you’re stuck you can carefully clip/trim the pins off the body of the part then desolder them one at a time although that obviously destroys the component.

For oddball components like D-PAK components or things with a thermal tab it can be worth treating them in 2 phases. The first would be to flow the solder on the smaller pins and bend them up until they’re free of the solder, then flow the solder on the tab and remove the component.

Another approach is to remove the solder from each joint one at a time with the solder braid. This is a fair bit trickier to do because usually the pin stays stuck to the PCB and trying to free it can pull the pad away from the board. Best done with large parts or under a magnifier so you verify that the pin is free by poking it lightly to see if it wiggles.

Regardless of what you’re removing, the most important thing is not to put much force until the solder is molten or you’ll tear the pads off the board. They’re only stuck down with glue and that glue softens with temperature.

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Thanks so much for all of that - once again I am still immersed in other projects, but I happen to have a collection of boards rescued from an old laser printer which will do admirably for a bit of mucking around in the not too distant future.

I have almost all of the gear listed, although my solder is dubious and my flux, well it’s some old plumbing flux that’s been in the family for as long as I can remember - I’m going to say before 1960! Chemically it’s a mystery, but it looks a lot like axle grease and behaves similarly when trying to solder anything with it. (I do have a flux “pen” which seems to work admirably on flat spots like led tape.)

Perhaps one of my kids can find a TS101 in time for my Birthday!

Oh, and the old Weller? Well it wasn’t a station, it was just a wooden handled 40w thing that would get hot after an age and then get cool just as I was ready to solder!

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