Un-bustin’ (monitor) caps with a soldering gat

There comes a point in every computer guy’s day when the phone rings, and a distraught acquaintance begins reciting error messages or describing some symptom of failure plaguing their Solitaire machine. Not too long ago, these calls were a welcome distraction. Perhaps they provided some validation of the countless hours spent peering into cathode ray tubes and liquid crystal matrices. Perhaps they were merely a common thread, facilitating rare interaction with other human beings. Whatever the reason, these tech support calls used to be a source of entertainment and pride.

Fast-forward a few years, and I’ve begun washing my hands of these support requests with canned responses like, “Google it,” “take it to a ‘Genius,'” or “that sucks, man.” Somewhere along the way, dialog boxes proclaiming missing DLL files, blue screens of death, and endless pop-up ads selling virus scans just got a bit boring. Once in a great while, however, these phone calls involve something a little more obscure: something hardware-related warranting a road trip to acquire new soldering gear. I was fortunate enough to receive one of these fun calls about a Samsung 216BW LCD monitor the other day. The problem? “It don’t work.”

After coaxing slightly-more-precise information out of the owner, some quality time on Google revealed a recurring theme of leaky and bursting capacitors on that particular model—a relatively easy fix. Cue the A-Team theme music. Soldering equipment, screwdrivers, safety glasses, Bawls, a multimeter, and replacement capacitors were all tossed on the work bench. The A-Team theme faded into Gonna Make You Sweat at a neighbor-enraging volume, the soldering iron was plugged in and heating up, and I was good to go.

Often, the most time consuming element of such a project is disassembling and reassembling the device without breaking or losing parts. While a monitor isn’t as intricate or as full of tiny screws and parts as, say, a laptop, it’s still worth jotting down where each screw came from on some scratch paper. This practice is even more important when the screws are of different sizes and threading. During disassembly, I like to use a digital camera or cell phone to snap some quick pictures before removing each component. This creates a digital breadcrumb trail that can be retraced when it comes time to put Humpty Dumpty back together again.

Once the monitor’s guts have been torn asunder, the misbehaving capacitors can be appropriately dealt with. Spotting a dead or dying electrolytic capacitor is usually pretty easy. They tend to bulge at the top, leak, or in extreme cases, explode. Modern electronic devices are starting to incorporate solid capacitors into their designs; those capacitors have a much higher life span and shouldn’t leak or bulge. Catastrophic explosion and fire are still in the cards, though, which makes my inner pyro quite happy.

When messing with capacitors—especially the larger ones found in CRT monitors—you need to be extremely careful to ensure that they have been fully discharged. Even if the device has been unplugged for days, these tiny tin cans might still pack enough punch to make the day pretty exciting after first contact with your tender digits. A quick check with a multimeter can determine if a capacitor is hiding some leftover voltage behind its back. Should there be some contraband juice stashed away, capacitors can be discharged by either shorting the leads with a something conductive like a screwdriver (not recommended) or by attaching some insulated wires to a bleeder resistor or a standard 60-100W light bulb until the voltage drops to a safe level. Non-conductive gloves would be a handy companion during this process.

Some claim that removing the power cord and pushing the power button several times will also discharge the capacitors. This is not always true. If it makes you feel better about things, then keep on pushing that button by all means, but check the caps with a multimeter before going hands-on. These days, many electronic devices that use capacitors also wire up a small bleeder resistor in parallel. This configuration is designed to gradually drain residual stored energy over time, but unless you know with certainty that the capacitors you’ll be handling have this feature, whip out the multimeter just to be safe.

Once the sparks have flown, all capacitors have been drained, and the pets have come out of hiding, it’s safe to remove the dead weight. The quick and dirty method is to simply yank the bad caps off with pliers, clip any remaining wire, and punch out the solder points with a sharp solder pick. If you’re in a more professional mood, remove the original solder by heating up the joint, place some desoldering wick on top of the joint, and run a hot soldering iron over the wick. The molten solder should be absorbed, allowing the capacitor to fall out cleanly once both leads have been freed from their tin restraints.

Before hastily slapping the new caps in place, take a second to ensure proper positive/negative orientation. The long lead is generally positive, and a quick glance at some neighboring capacitors will reveal any visual cues on the PCB that indicate which lead goes through which hole. Generally, the PCB will have a silk-screened circle marking indicating where the capacitor should sit. Half of that circle will be filled in or hashed, while the other half will be blank. The filled-in portion typically indicates the location of the negative lead hole.

Thread the legs through the solder point holes and flare the ends out to hold it in place while solder is being applied. If some rogue solder is preventing the lead from poking through, carefully punch out the hole using a sharp pick or needle.

Just like playing a musical instrument or quickly solving a Rubik’s Cube, mastering the art of soldering requires practice, practice, practice. I don’t consider myself an old soldering pro by any means, but enough electronic repair opportunities have popped up over the years that I’ve picked up a few handy tips along the way. The trick to a solid solder joint is preheating the receiving area a bit and applying just the right amount of solder in one smooth motion. Apply too little, and it might not stay put. Too much makes the joint brittle and prone to cracking. Overheating and remelting solder further weakens it, so getting it right on the first dab is critical. If you’re not comfortable wielding a soldering gat yet, bust off a couple rounds on some scrap wire or aluminum foil before dropping molten metal on your gear.

Once you’re ready to seal the deal, use the heat-and-dab technique on both capacitor leads. There may be other solder joints in the vicinity, and you need to be careful not to accidentally cross-connect them in the process. Should something go awry, this is where the desoldering wick steps in to save the day. Simply heat up the misplaced solder, apply the wick, and soak up your mistake.

With the solder applied and the capacitors held firmly in place, snip off the excess lead wires as close to the solder joints as possible, then reassemble. Tada! Good as new… hopefully.

When money is tight and the only thing holding back your hardware is a bum capacitor, DIY replacement can be an extremely economical way to go. Over the years, I’ve successfully saved several motherboards, video cards, and monitors from the scrap pile with simple cap replacements. The total cost of this repair including new capacitors, a new soldering iron, and desoldering wick was about $15. A new monitor could easily run you 10 times that.

Some replacement parts can be sourced from local electronic hobbyist retail stores like Radio Shack, but more often than not, they won’t have the proper capacitor in stock. My personal favorite destination for capacitor shopping is Digi-Key. They stock just about every conceivable electronic component under the sun, and their prices are reasonable. You’ll want to break out a ruler, since capacitors come in a wide range of heights and diameters. Also make note of the voltage and Farad (µF) ratings written on the capacitor(s) being replaced.

I’m sure this procedure is old-hat to many readers out there, but for those still earning their spurs, resurrecting a piece of kit like this is a sure-fire way to up your geek-cred. Just mind the obligatory warnings about eye protection, hot things burning other things, and electrical safety.

Comments closed
    • cynan
    • 8 years ago

    Man, I thought I was at least mediocre at electronics soldering until recently, when I tried to mod a Creative X-FI card by replacing the surface mounted OPAMPs, a main power cap and some conditioning caps. I did the surface mount stuff first as I thought the removal of the caps would be relatively easy in comparison. After replacing the OPAMPs, I was thrilled to see that the card worked like a charm. The larger power cap replacement went more or less OK too.

    When removing some of the conditioning caps, however, I failed utterly. The damn card kept sucking all the heat and, eventually, I ended up using too much heat for too long and damaged something beyond my ability to diagnose or repair.

    Does anyone have any tips on how to tackle this sort of problem (besides something like “learn how to solder properly”)?

      • ludi
      • 8 years ago

      Much of the time, one leg of the filter cap is soldered into the PCB ground plane, which acts as an effective heatsink. I usually deal with these by turning up the temperature on my variable-temp iron, removing excess solder from the pad with the desoldering braid, and then “walking” the cap out as JBI described. If it doesn’t come out in 2-3 seconds, remove heat, allow a minute of cooling time, then try again. You may even need to “push” the leg out of the hole using a fine-point soldering iron tip.

      This usually works because the solder has to be soft, but not necessarily all the way to reflow temperature, for the stuck leg to pull loose. Then, quickly clean out the hole with a fine-point soldering tip and let the board cool for a few minutes before installing the replacement component.

      • dwhess
      • 8 years ago

      There is really no substitute for a temperature controlled soldering iron with a large heat capacity tip when desoldering parts. My favorite are any of the Weller Magnastat irons with the largest 700 degree chisel tip you can find.

      I just modified a Weller manual desoldering tool by adding a vacuum pump to replace some 28 pin DIP parts with sockets but that is overkill if you have just one project. It will make incredibly short work of the next set of capacitors I change though.

    • just brew it!
    • 8 years ago

    My preferred method for removing bad caps is to alternately heat each lead and “walk” the capacitor out by pushing sideways on the top of the capacitor. Then once the cap is out, use a solder sucker to clear the holes.

    Got lots of practice a few years back, at the height of the motherboard “capacitor plague”.

    I’ve also got a pile of older (but still potentially useful) video cards that I plan to recap soon…

    • CaptTomato
    • 8 years ago

    So basically manufactures are deliberating sabotaging some of their consumer products.

      • mnemonick
      • 8 years ago

      More like they’re buying the cheapest parts they can get so they can sell crappy TN panels for $149 and still make something on the deal.

    • blanchjd
    • 8 years ago

    Excellent post, and good information for those new to electonics repair. I’ve fixed about 8 different monitors, two power supplies, and one motherboard (twice) all with simple cap replacements over the past few years. For reference, another good resource is badcaps.net. Extremely helpful information over there about repair problems.

    The best thing about monitors, is that dead ones are plentiful, and easy to repair. Those of you working in a corporate environment, the IT department is a great place to pick up dead LCD monitors if you are buddies with the techs (if they are planning on throwing them out). In fact thats where I got three identical (dead) 20″ wide screen monitors for my Eyefinity setup. $10 later in caps, and I was in business. Ebay can also be useful for similar purposes, but of course, with purchasing known bad stuff, sometimes you get left with an unfixable piece.

    As for soldering tools, if you can’t afford a real solder sucker, a desoldering pump is nearly as good, and is relatively cheap:
    [url<]http://www.mouser.com/ProductDetail/OK-Industries/DP-100/?qs=sGAEpiMZZMt%252biMJH3c40u%252b4zSou0zc0r9EoKX2I%2fA1U%3d[/url<] Good equipment goes a long way in making this kind of stuff easier. I even picked up a broken Metcal soldering station and fixed it to improve my arsenal of tools.

    • SHOES
    • 8 years ago

    Do this all the time just fixed my dads 40″ samsung tv… Very common nowadays as these LCDs approach 5 years + in age the cheap caps they use start to show signs of overwork. Its worth noting you can use higher voltage capacitors without trouble although you want to make sure that its the same physical size so it fits. The voltage is a tolerance so if possible I like to step it up by about 5v to possibly extend the life.

    • The Swamp
    • 8 years ago

    I have a really nice Samsung 24″ monitor that died because of bad caps. It’s a super nice LCD, and I cannot bear to toss it in the trash over $7 worth of caps. I’m trying to find a good way to ship it to JBI since he’s a ninja with a soldering iron and a bag of caps. And I’d have a perfectly good working LCD for my computer lab. It’s a shame Samsung is getting a terrible rep like this, as I remember a time when they were the bomb when it came to LCD displays. I guess it’s like the old IBM hard drives. They were regarded as the very best you could get, then came the GXP-75 debacle. Their reputation was so tainted they had to sell off the entire business. I will never understand why hardware makers do this to themselves.

    • Bauxite
    • 8 years ago

    I wonder what the real cost of all those bad capacitors really is, its billions obviously but how many digits…

    • Ashbringer
    • 8 years ago

    I did this myself a year ago for my friend. His LCD wouldn’t turn on, and taking apart the monitor showed bulging capacitors. Some quick soldering and a bunch of capacitors off ebay got it working again in minutes.

    Bulging capacitors are easy to find, it’s the weak solder joints that are harder to spot. Nowadays there’s a lot of cheap solder in electronics and it’s causing some major problems. Nothing that a solder gun or a heat gun won’t fix.

      • Ashbringer
      • 8 years ago

      Just fixed another friends monitor today. Some 5 year old HP monitor that wasn’t even wide screen. It would turn on and then off after 2 seconds. Took it apart and found one bad capacitor. Problem is that my friend wanted it working today, and Radio Shack didn’t have a matching 100% capacitor. Original was 1000µF 25V 105 degree capacitor, while the one I found at Radio Shack is 1000µF 35V 85 degree. It was nearly twice the size of the original capacitor, but I got it to fit with some careful placement. Put it together and ran it for 5 minutes and it works.

      The Voltage isn’t a concern cause the new capacitor is rated for higher voltage, but the temperature is concerning. The new one isn’t rated for as much temperature as the old one. Hopefully that since it can handle more voltage and is twice as large, maybe it won’t get nearly as hot.

      If anything, it wasn’t like I got paid for this, or was my friend willing to wait for the proper part. Interesting that it works either way.

    • puppetworx
    • 8 years ago

    Just found some bulging caps on my friends erratic motherboard near the CPU and it turns out I can pick up replacement caps for pennies. If it wasn’t for this article I would never have know how to check or considered replacement as an option, thankyou my man.

    • rephlex
    • 8 years ago

    From the article: “Too much makes the joint brittle and prone to cracking. Overheating and remelting solder further weakens it, so getting it right on the first dab is critical.”

    Both of these statements are false. Too much solder is just a waste, up to a point using more solder than necessary will actually make the joint stronger and therefore less likely to crack as cracks are nearly always a result of mechanical stress. Remelting solder does not weaken it and is actually the right thing to do if the solder was not totally stationary during the transition from liquid to solid. Getting it right on the first attempt saves time, but nothing more.

    • SAMSAMHA
    • 8 years ago

    Man, I hope you are actually nearby to help me fixing my trusty gateway FPD2485W display that also suffered a very common and well documented issue where the cap is gone and cause it not able to display images. I love the display so much but unfortunately I cannot use it now as I would have to literarrly sitting here power on and off like a billion times over a couple of hours to maybe lucky enouch to get some image.I konw it’s an easy fix but unfortunately I am not as technically knowledgeable with teh whole soldering. Anyone local can help out.

      • Firestarter
      • 8 years ago

      You should read a soldering tutorial or even get some classes, practice a bit and just do it! I mean, the display is for all practical purposes dead and you weren’t going to get it repaired or you would already have done it. So worst case scenario is that it’s still dead and you hurt yourself despite all the warnings about hot soldering irons and capacitors zapping you. Being warned about this, you should be able to at least safely try and get that display working again.

      Just remember to take your time. If you feel rushed in the slightest of ways, just stop and go do something else, because wanting to rush through your first real soldering job is a good way to get burned/shocked.

        • SAMSAMHA
        • 8 years ago

        Thank you so much for your reply. I know, I would have loved to but really have no experience with soldering. I don’t want to risk it at the moment.

        I have not yet got it replaced because places that fixes monitor charges like 150 for the repair. That is like the cost of a brand new monitor. I am debating if I should even have it repaired. I cannot believe for like 10 material, they charge so much for it. I really love this monitor because it has such a nice quality but crappy cap that gateway uses inside the monitor just sucks. My 19” dell lasts longer than this.

        Anyone local in LA area wants to help someone out?

    • thefumigator
    • 8 years ago

    I do the same with old motherboards
    When I can’t find the same voltage rating, I just use a higher one. Of course they are bigger, but they’ll work fine. The problem is when the voltage regulators are the one to blame (ie: they are burnt and in short cut) in this case things become problematic, as voltage regulators aren’t easy to get nor to desolder.

      • just brew it!
      • 8 years ago

      Actually… I’ve done the regulators (MOSFETs) too, and it isn’t *that* bad. But yeah, it’s more of a “personal challenge” sort of thing. Probably better off just junking the motherboard, especially if multiple MOSFETs are blown.

    • Dposcorp
    • 8 years ago

    Excellent Job David; thank you.
    Also, excellent job with the comments everyone. Nice to see

    • thesmileman
    • 8 years ago

    Nothing like some Bawls!

    🙂

    • wierdo
    • 8 years ago

    I love reading articles like these that get into such cool things to try, but I think this is the sort of topic that just begs for more step by step pictures and diagrams, and if possible some video clips.

    Sometimes words are a little vague for something like this. News and reviews are easier to explain with words, but this kinda project lends itself better to visual illustrations imho.

    • dashbarron
    • 8 years ago

    Never ventured into this territory. Always heard about the hidden power problems and was afraid of burnt digits. Plus, I’ve never been sure of when this is a capacitor problem beside taking apart the device and looking at it. If an electrical surge hits or the component is dead, is a bad capacitor a safe and sure bet to look at first?

      • tanker27
      • 8 years ago

      Bad caps are easy to spot. If the top is not flat and is bulging its bad. Obviously if its leaking ‘stuff’ its bad too.

    • Glix
    • 8 years ago

    After reading all this, I still have one question: Did you get the monitor working? 😀

      • David_Morgan
      • 8 years ago

      Yessir! 🙂 I’m officially 3 for 3 now on getting these silly Samsung monitors back in service, with only one soldering iron scar to show for it. A pretty good ratio in my mind.

        • not@home
        • 8 years ago

        I have replaced Lots of caps on Samsung monitors. It is a side job for me. It helps that I was a CRT technician and already have a whole reworking station and more experience that I care to admit. The desolder iron in my reworking station makes things much much faster than using a solder wick. It is a Hakko 703. One note: do not yank the bad cap to remove it. You could tear the trace on the solder side of the board or rip of the solder bump where the cap is soldered to the trace and ruin the whole thing. Always properly desolder with either a solder wick or a desoldering iron.

          • Aphasia
          • 8 years ago

          To bad most desoldering irons are a bit expensive compared to what most people really have use for for easy reparis, because they are wonderful to work with compared to the manual “suckers”. Especially the better stations.

          Never did get one myself, but I did a whole lot of work with em back in my teens. For a while I did some work exchanging red LED’s on queue boards that are used to show the queue numbers in stores. It’s was about ~40 LED/digit, 2/3 digits per board. After a bunch of boards each day you really appreciate having a proper combined soldering/desoldering station.

    • tanker27
    • 8 years ago

    Even though I learned and perfected my soldering technique on Samsung TVs and Monitors It swears me off this Brand forever. (I dont care how good their LED TVs look!)

    Damn Samsung and their cheap caps!

    • Taircron
    • 8 years ago

    As someone who teaches soldering, components, and electrical engineering, and consults in consumer electronics, I recommend putting a few more warnings/explanations in there. In particular:

    – Long lead is a /horrible/ way to determine capacitor polarization (or diode polarization, etc). Almost 10% of manufacturers do it the other way. Worse, if you clip a lead, or someone else did, or there was a manufacturing glitch, and you get it backwards, the cap will explode after a short time powered up, creating a fire hazard. Instead, check the labeling on the caps, both before you remove them, and after you install them. It is not uncommon for a PCB silkscreen to have inaccuracies on it, especially regarding polarization. As such, many PCB assembly houses have assembly sheets they use that tell them when to ignore the silkscreen, because it’s wrong. Simply trusting the silk gives you a 1/500 chance that the silk is incorrect, causing said explosion. It’s much safer to trust the markings on the cap that was installed by the tech, who had the documentation with him. All in all, it comes back to reading the labeling on the caps.

    – Safety wise, you also make a comment that charged caps can “…make the day pretty exciting…”. This is incorrect. Contact can cause burns, trips to the ER, and death, especially on certain technologies that use high voltages. The physical response to the shock might even cause you to jab yourself with a hot iron, fall out of your chair and hit your head, etc. I appreciate the humor (and it is a well written sentence), but it’s something people should be aware of.

    Not to be a downer, but cap orientation and understanding the associated risks of shock are important, and since this site has such credibility, and thus trust from the community, I hate to see risks glossed over. It’s easily a perfectly safe thing to do, especially if you test voltages and wear gloves and eye protection – but making sure that you do those things is important.

      • Arclight
      • 8 years ago

      You Sir should be our Labour Safety Representative. If it’s a democracy, you got my vote.

      • Corrado
      • 8 years ago

      Is that you, Buzz Killington?

      • David_Morgan
      • 8 years ago

      Thanks for taking the time to write this Taircron. Electrical safety is incredibly important, and as the scope of this little blog post was intended to be a chronicle of the repair of one monitor, rather than a full on soldering tutorial, I can understand how my safety remarks could seem “glossed over”.

      Your capacitor orientation notes are a great addendum as well. You clarified what I was driving at when I said:
      [quote<]a quick glance at some neighboring capacitors will reveal any visual cues on the PCB that indicate which lead goes through which hole"[/quote<] I should have mentioned to look at the labels as well. Good call.

        • ludi
        • 8 years ago

        Yes, always look at the labels AS YOU ARE REMOVING THE OLD UNITS. Take a couple quick snaps with your cell phone camera, draw a quick diagram, whatever it takes. I do this frequently during electronics repair and it routinely saves my bacon. One time I didn’t, and had a motherboard cap explode on me because…the silkscreen was labeled backwards. Fortunately, it was one of the smaller caps and nobody’s face was in the way, but it can and does happen.

      • SomeOtherGeek
      • 8 years ago

      Awesome, thanks for sharing. It is indeed important. I like the fact that David was humble about it. Love the blog BTW!

    • scpulp
    • 8 years ago

    You’re gonna notice a lot of these monitors with bad caps are Samsungs; I’ve seen two monitors and a TV die that way.

    Don’t know what the deal is, but I’ll never buy a Samsung screen again.

      • Zoomer
      • 8 years ago

      Yeah, our department had lots of samsung monitors and their backlight would fail. Our sysadmin would wait for a couple to pile up and then bust out his iron.

      By the way, are there any issues with using 60/40 solder with these RoHS parts?

        • RobbyBob
        • 8 years ago

        I was always told by my electronics instructor that for delicate electronics repair, Sn63 flux-core is what you should use. That was probably because of the lower liquidus temperature.

        • ludi
        • 8 years ago

        [quote<]By the way, are there any issues with using 60/40 solder with these RoHS parts?[/quote<] There shouldn't be. The lead-free stuff is tricky to work with because of the higher reflow temperature, the greater risk of overheating the connection, and the greater risk of a cold joint forming as the solder sets. The leaded solder flows at a lower temperature, making it less risky to work with. Once you wick the old solder out of the connection using the copper braid, any residual solder on the pad will readily flow into, and alloy with, the leaded solder.

          • willmore
          • 8 years ago

          Get a sample piece of chip-quick and try it. It’s a very low melting point solder that, when it combines with the higher temp RoHS stuff allows normal working temps.

          • Zoomer
          • 8 years ago

          Great. Just wanted to make sure mixing them wouldn’t cause undue brittleness or lifespan issues down the road. Depending on the price, not sure if I would use the best caps on them since other parts of the panel would likely fail before the new caps crap out again anyway.

      • indeego
      • 8 years ago

      This is funny. My Samsung 2493HM [i<]just died yesterday.[/i<] It had three days left on its warranty (September 2008 was purchase date.) I think there was more wrong to it than the LCD as the speakers were making a ticking noise constantly. Hopefully they give me an upgraded model.

        • tanker27
        • 8 years ago

        Dont hold your breath. I’m surprised even that they would honor the warranty with three days left.

          • indeego
          • 8 years ago

          Samsung support was great. Hold time was maybe 10 seconds, No arguing at all from them. We couldn’t run a self-test, they pay for shipping, I should have it early next week.

            • indeego
            • 8 years ago

            Whoops! We just had another one of these die today. So scratch my rave for Samsung. It does almost seem like they want these to deliberately die after the warranty runs out.

            New monitor shopping time! I don’t have the balls or patience to try something like this on a monitor.

    • Bensam123
    • 8 years ago

    [quote<]Fast-forward a few years, and I've begun washing my hands of these support requests with canned responses like, "Google it," "take it to a 'Genius,'" or "that sucks, man." Somewhere along the way, dialog boxes proclaiming missing DLL files, blue screens of death, and endless pop-up ads selling virus scans just got a bit boring.[/quote<] The difference being in school there was recognition, the chance to show off skills, gratitude, and an overall sense of accomplishment. After you get out of school (or even college) it loses a lot of the attention it once got. People take it for granted and often time think fixing electronic devices doesn't take a lot of time, simply because you're sitting in front of it and you don't move. It's quite sad and definitely doesn't make me want to help out friends, especially when a lot of them just bitch at you while you're fixing things because they seem to think they know better (even though you're there because they don't in the first place). Now that is more infuriating then not being appreciated. Very nice little guide though. Props on taking the time to write this and share it... I'm surprised this wasn't made into a little feature instead of a blog. Is that solder tape or something like that? Seems like it would make things a lot easier. +1 vote for this being a featurette.

      • Corrado
      • 8 years ago

      The ‘tape’ is desoldering braid. When you heat this up, it draws the solder to it, removing it from the board. You can also use a solder sucker, which is essentially a soldering iron with a vacuum bubble on the end that once the solder is melted, you release the bubble and it sucks up the solder.

        • ludi
        • 8 years ago

        A suggestion to go with that: Use the braid whenever possible. I do it both ways depending on the project but the braid makes a cleaner job of it, especially for a novice working on commercial circuit boards. Less risk of solder spatter and also “sinks” some of the excess heat, reducing the risk of damage to the board or components.

        Just have to make sure the braid isn’t pressing against other connections during the operation as you can quickly desolder more things than intended.

        • Bensam123
        • 8 years ago

        I’ve never used a desolder braid or even heard of them, very cool and sounds extremely helpful. I have used a solder sucker before.

    • Coulda
    • 8 years ago

    I recently replaced 3 caps on my Samsung 226BW LCD monitor and brought it back to life using cheap soldering iron. It was low wattage iron so it was tedious to de-solder/solder but the end result looked tidy enough. The soldering kit I bought came with de-soldering pump which I found useless. Didn’t use any fancy tools, just the soldering iron. Used a nail clipper to cut off wires…lol

      • thermistor
      • 8 years ago

      Dude! The 226BW and the 225BW share the same LCD, only difference is the signal board (not sure of the exact name) gives the 226BW panel a higher refresh rate. One of my 225’s is really a 226LCD in a 225 frame.

      I have also soldered in new CCFL bulbs into the 225BW’s. That was a lot of freaking work and should really be done in a clean room to avoid trapping dust inside the layers of plastic that makes up the panel. But on a budget I can ignore a few dust shadows. Also the Kapton sheet that holds all the circuitry and the glass LCD is really fragile.

      The 2XXBW series all share similar power inverter boards (I took a peak inside a 205BW at work). But Viewsonic, Acer, and others all have similar Cap problems.

      Digikey is *the* place to go, but go with the high reliability, low impedance type of cap. They are just a bit more than cheap caps. Also, replace all the caps, not just the ones that look bad. Bad caps don’t always swell. With Digikey’s first class mail, I was able to get the all the caps, plus postage for about $7 IIRC. The warning about height/diameter is well heeded.

      The cheap Chinese caps in the OEM LCD last only so long, Nichicon or United Chemi Con will last far longer.

      I made my budget Eyefinity setup with 3 of the 225BW’s, two of which were e-bay repair jobs to match the retail bought unit. 3x1680x1050 resolution is OK, but even that makes my 6850 choke.

      Great article – it gives anyone so inclined to DIY a good starting reference. Cheers to the soldering experts – I will follow your recommendations.

        • Zoomer
        • 8 years ago

        Oh yeah, definitely buy a few more or a few times what you need, particularly if the components cost is dwarfed by shipping.

    • videobits
    • 8 years ago

    While I personally would avoid soldering on a PCB without a temperature controlled soldering iron, I understand that this article was about saving money.

    Still, it pains me to see those giant diagonal cutters being used. Folks near a Harbor Freight can get a surprisingly decent set of flush cutters for 2 and half bucks.
    [url<]http://www.harborfreight.com/micro-flush-cutter-90708.html[/url<] And if you do have some more money left over, a good soldering station like a Hakko 936 or similar can be found on ebay for $50-75. A good investment that should last you a lifetime if not abused. The article didn't mention 'tinning' the iron before soldering. This is melting some solder on the tip which is critical for heat transfer. This should also be done before using the solder wick. Your pic obviously is of your out of the box iron which has not had this done. Nice article overall as this is a fairly simply task. You might also note that if you can't find a replacement cap with the same voltage rating using the next step up is safe just keep the Farads the same.

      • willmore
      • 8 years ago

      Good advice there, videobits. I’ve been soldering since I was a kid and I’ve gone from an unregulated iron, to an unregulated iron on a dimmer box to a regulated iron. Each step of the way made soldering much easier.

      The unregulated iron on a dimmer box works for almost everything except modern multilayer boards with power/ground planes–because designers appear to have forgotten about proper thermal reliefs. Once you need some more wattage, the regulated iron beats the pants off of the dimmer box iron.

      Also, what’s with the bottle of stimulant? My #1 rule for soldering is to avoid *any* stimulants. Then again, I tend to do SMT soldering and not big ‘ol through hole work.

      On the safety side, these are 25V caps, there’s no real safety issue here. If they were boostcaps, maybe, but these are little tiny ‘litics. If these caps were in the primary side of the switching power supply (which very well may be on this same board and even nearby), then I’d be *way* more careful. Those caps are often 200-450V (depending on power supply design) and can store enough energy to cause an ER visit or worse. Be careful and live to solder another day.

        • mnemonick
        • 8 years ago

        Heh, should have read your whole reply before posting mine. 🙂

        (You have your own B&L binocular scope don’t you? Be honest, now. :D)

      • mnemonick
      • 8 years ago

      Yes, this is all good stuff. And if you are cheap, you can even make a temp controller from an AC “work box” (with cover) and a 600w light dimmer (and one of those dozen spare IEC power cords you’ve got lying around) for about $15. Combine that with a 25w Weller iron and you’ve got yourself a nice little soldering station for PCB work. 😀

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