Help, I suck at desoldering through mount components!

Coppercloud

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Ok, so I'm trying to replace some joysticks on PS5 controllers. I've tried stuff like this in the past to mixed success. I have a cheap solder iron and solder pump. This is not fun. Soldering? Not that difficult. Getting the through mount device out? Kill me.

At this point I think my biggest problem is my crappy solder sucker. It's the cheap pack-in thing that came with my cheap iron. You probably know the type something like this. The engineer brand sucker seems highly recommended as its tip is flexible silicone and can thus make a seal around the soldering point and really suck it all out. See here.

But I've been wondering if one of these units that heats and sucks isn't worth the try. Seems a little janky, but there would be no motion to go from the iron to the pump where the solder can cool. $40 isn't cheap, but it's a lot cheaper than the $200 $300 unit I saw recommended from ifixit that is probably wonderful and provides continuous motorized suction, but is also pretty expensive for a guy that just tinkers with this.

So, any tips? Are either of the engineer sucker or the electric desoldering iron likely to be a let down? Because I just cannot get this stuff to detach. Someday I'd love to have a good desoldering gun and hot air rework station and decent iron, but it's not in the cards where I'm at with how much I actually do this work. Kind of a paradox where the cheaper gear works poorly making it hard to get into it to the point where you could validate the more expensive gear innit?

Or maybe I'm bad at this? I'm doing my best to have flux in there, add a little fresh solder and tin my iron, and then heat the component not the solder, but... Well I did one controller (12 or 14 solder points) in 2 hours. I've spent another hour on the next and made little real progress when I was hoping I'd have an easier time the second go.

The other problem is the unit seems unfortunately difficult to replace. It's not a simple resistor or something with only two contacts that you can take out one joint at a time. You can pull the two pots off individually and that's not too hard. But you're still left with a 6 or 8 peg through mount thing that you basically have to remove all the solder because it has to be pulled out as one piece.
 
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Using solder suckers is an art tbh, the engineer makes it a little easier but depending on the quality of the solder lead, board and component leads, you may still need to follow up cleaning with solder wick.

TBH, If the board's traces arent as delicate, you might be better served by using a wick from the start.

As for electric desoldering systems, what i see recommended more instead of the hakko is the station type ZD985 or it's clones/revisions. Those work a lot better than the wand/stick type. If you're doing this a lot, i'd go this route.
 

Coppercloud

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What about desoldering needles? Those would let you mechanically break the connection in the through holes one at a time.
Did a little looking and I don't see a lot of info or products out for these. Have a recommendation on which one to get? And I saw a video where the guy heated a component from one side of the board then inserted the needle from the other. Think there'd be any issues to hearing from the same side you're pushing the needle in through? Because with the way the joystick unit is there are at least 6 points in not able to access to heat from the back.
 
I grew up in a shop that assembled through mount boards pretty much exclusively.

How we did it - you clip the leads as close to the pad as possible. When you're done with that, you add a tiny dab of fresh solder on the pad to help heat and liquify the existing solder. With a pair of pliers you work the lead out of the hole. You have to be fairly quick though, because if you apply the iron tip to the pad too long you can damage the board. If you don't heat it up enough and try to force the lead out of the hole you can rip the pad off or, if it's a double sided board, pull the tube out of the hole.

That was when we were fixing one-of's generally. When we had a lot of parts to replace we had vacuum irons to do the job.
 

Coppercloud

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How we did it - you clip the leads as close to the pad as possible. When you're done with that, you add a tiny dab of fresh solder on the pad to help heat and liquify the existing solder. With a pair of pliers you work the lead out of the hole.
The problem is when doing something like this it's hard to work them out one lead at a time.

1714311093209.jpeg
 

Shavano

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Low melting solder. It's one kind of low-melting point solder. It's a trick that really helps cleaning out holes and getting solder off places without damaging the board.

Indium-bismuth alloy melts at 72C. You alloy it with the solder that's already on the board and it lowers the melting point to a temperature that won't damage the board. You need to clean it out thoroughly with solder wick after you're done and clean up the area pretty well when you're done for the same reason. But it really helps getting the solder to wick out of holes with an iron at a temperature that won't damage the board.

Available from Digikey as item SMDIN66.3BI33.7

You will need some wick to help with the cleanup.

Also Indium-Bismuth is less toxic than many other low-melting solders. The particular product number is lead free, RoHS and REACH compliant and eutectic. But of course if you alloy it while desoldering with lead-containing solder you've still got hazardous waste that needs proper handling and disposal.

Also if you don't need to save the chips or connectors, cutting them off with some clippers so you don't have to deal with more than one pin at a time helps.
 
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Oh yeah forgot to add, Most of the time you can 'break' apart these analog assemblies into components, the green part that holds the resistive track can be pryed then bent away and you can desolder those first (or in some cases, just replace those parts without taking out the whole thing).


View: https://www.youtube.com/shorts/bqOo0NsxXfU
 

Wheels Of Confusion

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The problem is when doing something like this it's hard to work them out one lead at a time.

View attachment 79569
For something like that you cut all the leads with a flush cutter (they're not just for Gunpla!), put extra flux over the stumps, and wick the whole side at once. Then, DON'T try to pry them out yet, repeat the process on all the sides. You can usually trim a little more lead-stump off as you reveal more by taking away the remaining solder.

Don't linger on any side, it's better to wick away small amounts and let the pads cool for another pass than trying to get all the solder at once.

Once you've removed a lot of the solder and have very flush leads, replace your iron's tip with the biggest chisel-style tip you can get that will cover an entire 2-side corner, drown it in flux, lay the wick across all the pins over those two sides and hit it with the big chisel tip while rocking back on the component from below to tip that corner out. You may need the help of something like a cross-stich needle to crowbar it out at that step, just be sure to have something insulating around the end you're holding it with. Or use something heftier that can sink the heat, like a dental pick.

Then repeat the hit-and-pry step on the other corner.
 

Coppercloud

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Oh yeah forgot to add, Most of the time you can 'break' apart these analog assemblies into components, the green part that holds the resistive track can be pryed then bent away and you can desolder those first (or in some cases, just replace those parts without taking out the whole thing).


View: https://www.youtube.com/shorts/bqOo0NsxXfU

I did do this as part of trying to get the joystick off. This is 50% me trying to repair a controller and 50% me trying to get better at this kind of work, so I'm still trying to do the whole replacement. But as a practical matter if I can't figure it out I'll probably just do the green pots.
 

andygoblins

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But I've been wondering if one of these units that heats and sucks isn't worth the try. Seems a little janky, but there would be no motion to go from the iron to the pump where the solder can cool. $40 isn't cheap, but it's a lot cheaper than the $200 $300 unit I saw recommended from ifixit that is probably wonderful and provides continuous motorized suction, but is also pretty expensive for a guy that just tinkers with this
Normally I don't believe in silver bullets, but after getting one of those Hakko vacuum pumps, I've changed my mind.

A through hole desoldering job that used to take me an hour with a pump and braid now takes 5 minutes. If you value your time in $/hr then this tool pays for itself very quickly.

FWIW the Japanese 100V model (available on eBay, Amazon) is only $170 and works fine on 120V US outlets. If you want it to last a long time then you can get a transformer and still be under budget compared to the marked up US model.

That's still pricey, but if you plan on doing other projects like me (I do a lot of classic video game console repairs) it's worth it.

If you go the cheaper route and get one of those pump/iron combos off Amazon, let me know how it works - I've always been curious if they were a good middle ground between suffering with a standalone pump and going all in with Hakko.
 

timezon3

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I saw a comment on reddit the other day that stick drift can be fixed on these types of potentiometers by popping the green part off and replacing the wiper or something along those lines. No desoldering. I've yet to try it on my own drifting controller. I agree that desoldering these damn things is really hard, with the 6 contacts. Actually IIRC from my disassembly attempt, it's more like 10 because there are also physical mount connections (that are soldered) plus the pins for the vertical push button.
 
I saw a comment on reddit the other day that stick drift can be fixed on these types of potentiometers by popping the green part off and replacing the wiper or something along those lines.
The wipers dont go bad as much as the resistive track (the green part). That's what causes the drift most of the time (the worn down center position).
But it's better to replace both (since if the track is chewed up, the wiper will likely just destroy the replacement anyways).
 

Coppercloud

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I saw a comment on reddit the other day that stick drift can be fixed on these types of potentiometers by popping the green part off and replacing the wiper or something along those lines. No desoldering. I've yet to try it on my own drifting controller. I agree that desoldering these damn things is really hard, with the 6 contacts. Actually IIRC from my disassembly attempt, it's more like 10 because there are also physical mount connections (that are soldered) plus the pins for the vertical push button.
If you do the full joystick it's 14 contacts. Otherwise 3 per pot.
 

Coppercloud

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Alright, so @Xenocrates swears by the desoldering needles. I wanted them to work. I could not get them to, much as I tried. I'm sure there is some operator error going on, and one of my challenges was that it's not just a simple two lead resistor or something that's easy to access both sides and get out one lead at a time. But alas I cannot recommend.

From there I got this thing from Amazon. I thought it might be a very cheap poor knock off solder vacuum that operated continuously. It is not. It's the equivalent of the pump iron combos just operated by a solenoid with a button, and... It wasn't bad.

If you go the cheaper route and get one of those pump/iron combos off Amazon, let me know how it works

I'd say this is absolutely a good option, or perhaps good enough. If you're budget constrained or just don't do this often this may be a tich finicky and will certainly not rival the hakko pump, but it will totally get the job done with just a little patience.

Specifically on my "automatic" one vs a manual. I'm not sure I would recommend this. I didn't realize that when I let go of the button the first thing it was going to do was slam down the plunger and spray my board with hot solder. So even though you don't have the motion to manually reset the device you still have to keep the button held and move it over to the side and let go in a safe direction. So I'm not sure not offers a lot of benefit over a manual one. I suppose if you were using it a lot that might be worth it, but you might at that time also be looking at the hakko or something. Furthermore every now and then the plunger would get stuck on it and you'd have to bang the thing against a table or against your hand a few times to get it working again.

Still, I'm glad I have it. I'd absolutely recommend it over solder braid or a regular pump. I did both joysticks on my Xbox controller today and experienced few issues. And everything works right after reassembly. Yay me!