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I have a PS4 controller that I want to replace the joystick on, so I disassembled the controller, added flux, added additional solder to all the joints, and removed the faulty joystick with a heat gun. Everything went well, but I ran into a few problems during the next step which was removing all the solder from the joints with a soldering iron, solder sucker, and a wick. The problem is that I have a few joints with a incredibly thin amount of solder that is quite difficult to remove since I can't get my iron and sucker on it at the same time. What is the best way to remove the solder (see picture 1)?

The mainboard with the problem areas circled.

I have tried adding additional solder, adding more flux, using a wick, and heating up the board with a heatgun then switching to the iron. I have even tried attaching a resistor to the joint, adding solder, and then attempting to remove the solder again. What do I do? Note: This is for fun/practice, and not for a professional repair, so I am willing to experiment.

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    \$\begingroup\$ "I can't get my iron and sucker on it at the same time" - yes you can. Iron on one side of the board, sucker on the other. \$\endgroup\$
    – brhans
    Oct 28, 2021 at 2:56
  • \$\begingroup\$ What's a "heatgun" in this context? One designed for desoldering or just a plain one that you'd use for shrink tubing and the like? The latter is usually not a great idea to use. \$\endgroup\$
    – Lundin
    Oct 28, 2021 at 13:08
  • \$\begingroup\$ There's an evil and not recommended hobbyist hack you can do: use thin pointy solder tips, jam it into the via, add more solder, apply wicker braid. Ideally you should be quick about this, though since these will be ground plane vias, you probably don't need to worry as much about heating it too long. The recommended professional solution would be to use a de-soldering station but I take it that's not an option here. \$\endgroup\$
    – Lundin
    Oct 28, 2021 at 13:16
  • \$\begingroup\$ Desperation: you can buy solder which is immensely weak mechanically. Apply to joint or pad, remove as usual then pick the rest off with a sharp tool. \$\endgroup\$
    – Russell McMahon ♦
    Oct 29, 2021 at 12:21

9 Answers 9

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I've heated up the solder to a little hotter than usual and knocked the circuit board lightly. A couple of knocks this way usually does it. My chosen tool for heating up solder hotter than usual is my 250W Radio Shack (I think a rebrand from Weller) -- I heat up the tip until it just starts to turn red, and then I can get in and get out quickly, which prevents damage to tracks and the board. Best of luck, and don't forget the goggles! :-)

My soldering iron looks like this one, but a little bigger:

enter image description here

This is mine:

enter image description here

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    \$\begingroup\$ I had 3 in total, even though the image shows 2. This solved two of them. I ended up doing getting the third one by rotating the board so that it was perpendicular to the floor, holding the iron to one side, and using the sucker from the other.. \$\endgroup\$
    – karafar
    Oct 28, 2021 at 1:13
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    \$\begingroup\$ Soldering guns like that are for sheet metal, heavy cables, and such. They should not be anywhere near an electronic circuit board. \$\endgroup\$
    – J...
    Oct 28, 2021 at 14:20
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    \$\begingroup\$ @J... - I only recently got a temperature-controlled soldering station, and I will admit that it's very nice. But I also learned how to use my "dangerous" tool very well, and without scorching things -- one adds heat until the solder melts, and with time and experience, one gets a sense of how much is needed. The 230 Watt iron will outclass the other when the smaller one reaches its wattage limit, when there's more heat going out than coming into the work-piece. So I like my six-shooter, and I'm not giving it up! It was necessary with the Maxwell 260F supercaps. \$\endgroup\$
    – MicroservicesOnDDD
    Oct 28, 2021 at 17:54
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    \$\begingroup\$ @MicroservicesOnDDD A good soldering gun isn't cheap. OP can buy a decent regulated electronic soldering station for the price of a decent solder gun and presumably has neither. An appropriate regulated soldering station with sufficient power and interchangeable tips would be by far the better investment for their foray into hobby electronics - I also, respectfully, disagree. \$\endgroup\$
    – J...
    Oct 29, 2021 at 13:10
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    \$\begingroup\$ @J... - Actually, I think I agree with you on that. Just don't tell everyone! ;-) \$\endgroup\$
    – MicroservicesOnDDD
    Oct 29, 2021 at 13:17
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You do NOT need anything fancy or elaborate tools to do this.

A 30W soldering iron, some 'good' solder wick about 2mm in width and some 'good' lead-based solder. And a short 'chisel' tip on the soldering iron.

The problem is twofold

  1. That's lead-free solder. Doesn't flow as well as lead-tin, and has a higher melting point
  2. Those holes all connect to ground planes - i.e. BIG HEAT SINKS.

Here's how to fix:

  1. Set gun to about 800F
  2. Use solder wick to get a bit of the original solder out
  3. Set gun to about 720F
  4. Feed GOOD lead-tin solder INTO the hole. This dilutes the lead-free solder, makes the solder wick MUCH more effective
  5. Go back to step 1

After 2-3 rounds of this, you'll have the hole cleaned out and looking like brand new.

At no time do you dwell with the soldering gun touching the board more than 2-3 seconds. If you don't get done what you want in 3 seconds - stop - let it cool - try again.

YouTUbe how to use solder-wick properly b4 trying this.

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  • \$\begingroup\$ This is how I've always done it \$\endgroup\$
    – SiHa
    Oct 28, 2021 at 13:59
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    \$\begingroup\$ "Feed GOOD lead-tin solder INTO the hole." I dislike the implication here that lead-free solder isn't "good". Lead-free solder is substantially better for both human health and the environment. \$\endgroup\$
    – nick012000
    Oct 29, 2021 at 9:51
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    \$\begingroup\$ @nick012000 Sorry to ruffle your feathers. Lead free is indeed a better environment choice. The implication was not a comparison of lead-free vs. lead, it was meant to suggest OP should be using HIGH QUALITY solder, not some random sh!t he might have sourced from Ebay. That said... OP, being a noob to this, will be fantastically better able to pull this off with lead-tin than with lead-free. IMO, lead-free is a HORRIBLE thing for the environment - It has accelerated the demise of many electronic products because it's SO BAD comparatively - things are going to landfill sooner than necessary \$\endgroup\$
    – Kyle B
    Oct 29, 2021 at 19:46
  • \$\begingroup\$ lead based has a lower melting point, and tbh, tends to work better other than the pesky risk of poisoning you eventually. I'd go with "old fashioned" over good tho. :D \$\endgroup\$
    – Journeyman Geek
    Oct 30, 2021 at 4:28
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I can't get my iron and sucker on it at the same time

There are soldering irons with a small hole in the tip, with a rubber bulb sucker attached. You squeeze the rubber bulb. Bring the soldering iron tip to the solder, melt it, then suddenly let go of the bulb. The solder will be sucked through the hole.

Search for de-soldering iron.

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  • \$\begingroup\$ Seems like a good tool to add to the arsenal, but it sucks having to wait a week to get one. \$\endgroup\$
    – karafar
    Oct 28, 2021 at 0:48
  • \$\begingroup\$ Can you recommend one off of ebay? \$\endgroup\$
    – karafar
    Oct 28, 2021 at 1:02
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    \$\begingroup\$ Product recommendations are off topic here. But search for "desolding iron" or "de-soldering iron". If you are in the US, you can easily find new ones in the $25 range, and can probably get quick shipping if you need it. \$\endgroup\$
    – Math Keeps Me Busy
    Oct 28, 2021 at 1:07
  • \$\begingroup\$ You can also get this as a separate tool, like this. I'm not endorsing this specific one or anything; it's just a cheap one that came up in a search. I've never had one of these not work, though, and I've used several of varying quality. \$\endgroup\$
    – Hearth
    Oct 28, 2021 at 1:57
  • \$\begingroup\$ @Hearth I hate those vacuums (unheated). I've only ever used high quality ones and still never gotten on to work for surface mount or when the solder is very close and low volume. That recoil. The bulbs are better because of the recoil but then they plug up and you either splash yourself with molten solder trying to unplug it or produce a cloud of lead dust. \$\endgroup\$
    – DKNguyen
    Oct 28, 2021 at 3:32
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As an alternative to banging the board to get the solder out, use compressed air. You can buy an aerosol can meant for cleaning keyboards (example.) I keep a can near my soldering station and use it to remove solder bridges on fine-pitch parts. It's quicker and potentially less damaging than solder wick. Be conscious of where the solder goes, but it'll be a hard ball before it hits anything.

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    \$\begingroup\$ I've also just used bulb style solder suckers to do this. Instead of using it to suck, I squeeze it hard and fast into the hole to blow out the solder. Example bulb: amazon.com/Desoldering-Soldering-Irons-Electronix-Express/dp/… \$\endgroup\$
    – computercarguy
    Oct 29, 2021 at 15:22
  • \$\begingroup\$ IIRC its inflammable , and might cool down the part. Its basically a hydrocarbon after all \$\endgroup\$
    – Journeyman Geek
    Oct 30, 2021 at 8:23
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A waterpik designed for cleening your teeth works great on stuff like this (use it empty). It can also be filled with IPA and used for cleaning tough spots around the pcb. It has saved me a few times on cleaning conformal coating out of female ended connectors after I got carried away with the application and let it leak in. enter image description here

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  • \$\begingroup\$ Obviously, don't use it on your teeth once you've used it on electrical equipment... \$\endgroup\$
    – nick012000
    Oct 29, 2021 at 9:52
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    \$\begingroup\$ @nick012000 Unless you like the taste, that is :) \$\endgroup\$
    – Dmitry Grigoryev
    Oct 29, 2021 at 12:36
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I can't get my iron and sucker on it at the same time

You can put the desoldering pump on one side of the PCB and the iron on the other side at the same time. Put the pump in place so that you only have to push a button to activate it, then keep it steady and apply the iron on the other side:

enter image description here

Obviously, you can't do it if you also hold the PCB in your hand, so you need a grip or a pair of clamps to do it. Sometimes it's possible to put the PCB on the edge of the workbench (so that the desoldering pump can reach the join from below), and put a heavy object on top to keep the PCB in place.

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  • \$\begingroup\$ This can most definitely be done without a clamp or vise, but it's not easy. \$\endgroup\$
    – computercarguy
    Oct 29, 2021 at 15:24
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Let me introduce a quick and dirty way that needs only an iron:

  1. Put on gobs of flux.
  2. Heat the joint as well as you can with an iron. Do overheat it a bit so it does not turn instantly solid when you retract; don't overheat it so long that all the flux burns before you finish.
  3. Knock/shake the board and the solder will drop out, leaving only a thin coating over the pad.
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I'm surprised nobody has suggested a product called Chip Quik, which is designed for just this kind of situation. This is a stick of bismuth alloy that mixes with solder and dramatically lowers its melting point.

The main advantage of Chip Quik is that it facilitates removing parts and solder without the need to overheat anything. The main disadvantage is that you must be hypervigilant in cleaning the product off the board before soldering new parts, because anything left behind will degrade the new solder joints.

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    \$\begingroup\$ ... which is a rather strong disadvantage \$\endgroup\$
    – tobalt
    Oct 28, 2021 at 16:55
  • \$\begingroup\$ Adding some leaded solder has a very similar effect, without the huge disadvantage (though with its own disadvantage of containing lead--not much of a problem on this scale, though.) \$\endgroup\$
    – Hearth
    Oct 30, 2021 at 3:34
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My way:

1.Add and fill the holes with leaded solder, this is very important;

2.Set your soldering station to the maximum temperature (400~450 degrees) and use the biggest tip you have on your soldering iron;

  1. Use the braid and put plenty of flux in the place you want to clean and in the braid itself.

  2. To make the hole cleaning process easier and faster use the hot air station at same time, set to 400 degrees towards the place where you are working at the same time.

  3. If you perform all these steps correctly, you will be able to complete the process 100 percent guaranteed.

Cheers

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