Desoldering tough components that won't come out! (Replacing Capacitors on motherboard)
2017 ж. 30 Там.
39 007 Рет қаралды
Just a quick video showing how you can better desolder components that are difficult to remove.
Just a quick video showing how you can better desolder components that are difficult to remove.
The reason adding solder works is called "heat transfer". Your tip is not contacting enough surface area to efficiently transfer heat by "heat conduction". Adding solder creates a pool of hot liquid that engulfs the soldering iron tip and the component legs and solder pad. The tip can then easily heat up all the parts to allow part removal.
You're dead on. The reason why the solder is so hard to melt on its own is because it's lead-free, which has a much higher melting point temp than leaded. Read somewhere that If you didn't put a coat of regular leaded solder you'd have to heat up the entire PCB to 150°C for seconds only in an airbath. if you preheat it then the lead-free will desolder almost as fast as regular leaded solder. I believe to repair it, you must first remove all of the lead-free solder completely and then resolder w/ lead 67-37. Mixing lead and lead-free solder yields a more brittle joint and more prone to breaking. I wonder though, does anyone know if using regular leaded 67-37 on a part that it's for lead-free (like a capacitor for instance) be the same as mixing the two types of solder and make an unreliable joint/solder?
This is such a great explanation! I was having a hard time one day removing components and with a mild grasp of thermodynamics I theorized adding solder to the tip might help intuitively. I felt like Issac Newton in that very moment!
Not quite... Most importantly leaded solder has lower melting temperature... With lead-free solder and temperature 300 degree C for example It will doesn't work but if you add leaded it will because leaded solder melts at 220-228 degree C, I belivie.
Also it works with leaded solder. You can also melt it at lower temperature if u add a alloy that melts at lower temperature then Sn60Pb30 or whatever u use, for example alloy with bizmuth which metls at 100 sth degree C - I don't remember exactly. ...
Generally better avoid that. Why? Perfectly explained here: kzhead.info/sun/dsagpbKfiIFrm5s/bejne.html
I ran into this issue tonight and could not figure out why the solder even at 750F would not melt the capacitor solder. Thank you for sharing this problem and solution. The only way to really learn is by doing it.
Part of the issue is modern boards are soldered with led free solder. U need more heat and a larger tip, but adding additional lead solder is always recommended to help flow the old solder, even if its not lead free.
thank you for this. the kinda comment i was looking for
You basically add and desolder, very long annoying process if you don't have a solder sucker. But it does work, just takes one extra time. Just make sure you're adding lead solder to the rohs, the further your mix them both the easier the rohs stuff will be removed @@jonmarsh7914
If you are going to desolder anything you need to use either flux or a flux pen with the wick, also use upwards of 350c temp and a clean tinned iron, the solder will jump onto the iron and wick instantly.
I have heard and found over the years that a lot of manufacturers used or are still using Silver Solder which has a much higher melting point. When you mix the two with a lower melting point melting solder heat transfer is greatly improved. Thanks for posting.
This is a great tip. I have picked up another from a discussion that preheating the entire board to 100 degrees will help with the power plane leeching heat which is thick copper layers. My little 23w iron is not cutting the mustard even with adding solder so i am having to wait for a temp controlled on that can do as high as 500C if needed
@Lucid Dev Team You did that wrong... You should use preheater to preheat the mainboard up to 120-150 degree C and then increase temperature on the soldering station until solder melts. Lead-free solder has higher melting point then leaded solder, so you have to use much higher temperature. Also preheating is key in this case, because mainboards has 8 layers and they has massive ground planes, so removing any component without preheater is nearly impossible - you can damage pads or damage the component due to exposure on heat for too long period of time... Generally speaking it is rly bad idea to replace anything on the multi-layer PCBs witout preheating, you had luck this time, but next time you can easly damge sth...
Awesome video. I figured this out the hard way. And I dont think just adding flux helps much. Also look into desoldering alloy. I've found you still have to add new solder first, but it has a low melting temp and gives you more time to remove components. The alloy then HAS to be removed completely.
Adding leaded solder to unleaded solder also helps lower the melting point. Good for component removal.
Yeah. Learnt this just recently. Was wondering why the old solder wasn't melting at all.
This saved my very expensive PCB and capacitors. Thanks so much.
Here's a crazy idea: You could leave in the existing leads from previous capacitors & instead try resoldering the new capacitors onto the existing pertruding legs from the previous ones. 😉😃
This worked like a charm for me! Thanks!
Great tip, thanks mate.
Helpful
I'm trying to desolder a transistor on a pcb and it won't freaking melt. Thanks for this video, I will try it out
Can you heat up the solder points with a heat gun and pull out the capacitor. Or would the capacitor explode.
I know this is an old video but I just did this yesterday. I figured this out to so that it was easy to get the caps out, but getting them back in was a mess, and the board didn't work afterwards. So, no joy. Have to replace the board.
Yea that's cool. But will it work with large components like a 8ga wire on a motherboard? Cuz I've heated the board and used 2 soldering irons and new solder n couldn't remove crap! I figured the wire was conducting heat so I cut it n I was able to desolder half of the solder... But there is still just a little and it's impossible to remove! I've tried Temps up to 460c!
did you figure it out
The name is thermo heat transfer if I'm not mistaken
I tried this and was getting no where then tried leaded and still couldn't get the positive side off safely so I'm stuck lol, think my mistake was not straightening the pins first but the board is sucking up to much of the heat to heat up the little ring enough to melt the solder nicely.
Good video. Thanks.
So what temp did you settle on for your iron. I've gone all the way up to 280 c, but still couldn't get the new solder to mix with the original.
I use 430 degrees.
I'm trying to desolder parts on my Xbox controller and they wouldn't melt so this helps me a lot. Thank you dude
Same
I'm running into the same issue, but even adding flux and solder does not seem to do aything ... I'm working on an old HP server motherboard from 2009.
I'm having the same exact issue
I hope this video helps a bit
dude i love you
glad I could help!
The way you remove those caps gives me anxiety. Especially with old boards, this is a great way to tear out the solder pads and even the traces.
It was a lot more difficult trying to do this while having it recorded. Just be careful when you do it
Im trying to replace a swollen capacitor in my old hifonics series 7 zeus car audio amplifier but i cannot get this capacitor out..... ARGGGGHHH... I tried adding solder and i got the little sucker thing that sucks up the old solder but i cant get it to let loose no matter what...... HELP......
Having issues with lead free solder on modern Asian made boards
thermo heat transfer
I gave up with this method and ordered a desoldering iron
This method worked, but now i have holes plugged with sodder. help
I'm able to get the old capacitors out, the problem is clearing the remaining solder well enough from the holes to get the replacement capacitors in. Maybe if I make a solder bridge between the two holes and heat that, I can still install the replacements and it won't matter that I didn't clear the holes?
Warm the solder up and push a needle through the hole. Easy.
@@shifty2755 Had to add more solder and heat it a while to clear it. Counter-intuitive.
@@hugesinker That is also a good solution 👍
Fanally !
I have to ask have you got over the learning curve?
I was trying to desolder a joystick on a controller, tried adding sauter, but still no results. I’m pretty sure my pump is just not strong enough. It’s a pretty cheap one, so I couldn’t get any out
Was it an Xbox one controller? The newer ones use tiny lead free joints, they are a nightmare to get off. I’ve been adding low melt alloy to get them off, it’s not cheap but it works. Also cut the old analog stick into bits, so just the pins show through, like on the vid
Nicky_Sparkle_Junior no, it was a PS4 controller
the leads doesnt mix
here is a good little tip when your removing components from boards, and want an easy way to clear the holes from solder: kzhead.info/sun/pJ2MlqiGh4KAaas/bejne.html
lead free solder is a bitch at rework. it kills your tip's lifespan, needs a proper flux or you'll get black tip syndrome, needs high temps, melts so ugly, etc. also, lead free makes everything expensive. fuck that solder.
Get a solder sucker! Doesn't matter if it's manual or powered... Add some new solder, then use the solder sucker to draw off the melted solder. Half the time the parts will simply fall out of the board leaving you with an open hole for the new part.
Just add new solder to the old solder so it flows again. Then suck it off.
Screwdriver tip would work much better.
I have wasted so much time trying to remove 2 capacitors. I tried high temp, solder wicks and more solder+ solder pump. I cut the capacitors off but am having issues even clearing the holes to put new capacitors in. Nightmare
I'm in the same boat. I think old unleaded solder is just terrible to try and remove. You need high temps, flux, along with mixing in new solder. Then if you are on the pad with high temps for too long, you ruin it. Soldering is sooo much easier than De-soldering.
@@overnightdelivery Agreed. I even bought new soldering irons including a TS100 type one and a Electric Vacuum Solder Sucker Desoldering Suction Pump Iron Gun Tin Soldering Repair Tool with 3 Nozzle EU Plug 220V 30W of aliexpress. I have just let it sit there. I may just solder things to the legs or reluctantly drill holes with a small drill bit as so fed up. Hope your position fairs better. I think they could use this solder for space reentry !
@@tarunarya1780 Believe it or not I've developed a pretty fool proof method for capacitors. Well.. for me at least. Not fast but effective: Temp at 700F. Always dab a bunch of flux over the legs you are De-soldering, then tin your iron with lots of solder(leaded melts better), have a solder sucker ready if your lucky you'll remove everything on the surface. After that you need to once again tin your iron and as you are applying solder you need to GENTLY rock the component you are trying to remove back and forth while keeping the heat applied. If you start hearing a squeeking noise, that means the leg is starting to move. If it doesn't start to move after 10 seconds or so, you use the solder sucker and repeat the process. Once it moves a little ways, hold the leg down in that position and let it cool. Then re-tin and use the same process on the other leg. Going back to the other leg you should be able to safely pull it through the hole while applying solder again. Repeat until it's out. Then I use wick over the holes, press and hold a tinned iron on top to remove excess solder covering the holes. You need to be very careful to not quickly remove the wick. Because it could be stuck if it's not hot enough and you could rip off the pads. Sometimes the wick will not remove enough solder from the holes. So then you can hold a toothpick on the other side of the board and use your iron on the other side. You then twist and bore out a wider hole, while keeping heat applied so your toothpick doesn't get stuck. Then use wick again to finish it off. It's still tedious but I've had a 100% success rate since. This applies to medium to large sized capacitors. May be more difficult with small stuff.
Thanks
The problem is your tip. You need a tip with more surface area - one with a flat tip.
So you bridge a capasitor.If that was carry a charge and it was electrolyte.Then it would explode in your face.
Thanks!!! I have been messing with a board and wanting to pull out my hair.