I can't desolder a female USB from an IC

Discussion in 'General Electronics Chat' started by rambomhtri, Nov 18, 2015.

  1. rambomhtri

    Thread Starter Member

    Nov 9, 2015
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    I've been trying to desolder a female USB from a PCI, but I can't. I've heated up the solder with the soldering iron, and when it was melted, I released the plunge with my solder sucker as close as I can. I've done this several times, sucking a good portion of solder. Nevertheless, the female USB is still rock solid stuck on the IC, it does not even move a single millimeter. I've also tried to press it gently, with my solder, in the opposite direction, but I can't move it at all.

    Untitled.png

    You can see I'm trying to remove the one on the left. It has 4+2 pins soldered. As you can notice, I've even broken the left "leg" of the female USB, I think due to the excessive heat I applied cause it was not moving. I've heated up every single pin and used the solder sucker several times. I don't know if it's my weak solder sucker, but it seems I can't get it any better.

    What should I do?
    What am I doing wrong?
     
  2. spinnaker

    AAC Fanatic!

    Oct 29, 2009
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    Do you need the PCB? If not then just cut it away from the connector. You can then clean up with your iron. Or better use a heat gun and forget the iron.
     
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  3. spinnaker

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    When you use the heat gun, heat it up, turn the board over and give it a smack. The part will fall out.
     
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  4. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    You are not applying enough heat..
    Heat it up more/longer.. put the solder sucker "mouth" directly over it and release..
    You are probably just heating up the surface but not giving it time for the heat to melt all the solder all the way through the through holes..

    If that didn't work.. heat it up again and apply a bit more solder.. yes more and then try again

    Desoldering takes far more skill than soldering..

    There is still tons of solder in those holes..
     
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  5. Roderick Young

    Member

    Feb 22, 2015
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    I'm assuming you're like me when I started out, and have a limited budget. (If you can spend, there are elegant solutions.)

    I would try to loosen the signal pins, first, and ignore the shell. Solder braid ("solder wick") would be very helpful for that, although maybe a solder sucker would work. The key is that after most of the solder is removed from the pin and hole, to wiggle the pin with a small screwdriver or needlenose pliers to be sure that any film of solder is broken. Make sure that those 4 pins are loose.

    Next, see if you can get a small screwdriver between the shell and the pcb. The bigger and hotter an iron you have, the better. Put solder on ONE pin of the shell, and heat it to melting. If your iron is hot enough, you will be able to gently pry that side of the shell out at that time, or at least get it moved up a little. Then repeat with the other side of the shell.
     
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  6. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    Sometimes more really is more. See if you can flood all six pins & supports with solder so you heat the entire assembly at one time. Then it should pull out easily, or even drop off by itself.
     
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  7. mcgyvr

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    Oct 15, 2009
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    hard to tell but are 2 of the signal pads (2 on the right side) starting to lift already?
     
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  8. takao21203

    Distinguished Member

    Apr 28, 2012
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    Yes you need a 50W iron and broad tip. A point tip never can deliver enough heat.
    Screwdrivers also help. Put new solder on the joint so you can distribute as much heat as possible.
     
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  9. rambomhtri

    Thread Starter Member

    Nov 9, 2015
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    I have a soldering station, 58W, it can go up to 480ºC. I think I tried it setting the knob to 300-350ºC. I think I melted all the solder, but I couldn't suck anymore. I'm gonna try to add solder and the suck it up.

    About making a bridge between everything... isn't that overkill or a total waste of solder? The area is "big".
     
  10. ian field

    Distinguished Member

    Oct 27, 2012
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    Since you didn't say - I'll guess that you want the connectors intact *AND* not damage the board.

    Concentrate first on the connector pins, ignore the mounting lugs for now.

    Run some fresh cored solder onto the connections - flux is the magic ingredient, it burns up and/or gets removed by the solder sucker. then the solder forms an oxide skin that makes removing it more difficult.

    You won't get totally 100% of the solder out of the holes, but when you've shifted most of it, you should be able to loosen the pins from what's left. Get hold of each pin with slim nosed pliers and make sure you can wiggle each pin round in its hole.

    Once you're certain each pin is free - you can easily unsolder each mounting lug and lift the connector out.

    If the connectors are scrap - sometimes its easier to dismantle it so the pins can be unsoldered as individual bits.

    If the board is scrap - I use a modellers pencil blowtorch, or as others have suggested; a hot air gun.

    Just to add an important point; never clean out the holes with a pin drill bit - it almost always damages the through plating.

    If the solder sucker doesn't clear the hole - melt the solder and unblock the hole with something that easily fits, stainless steel wire if you can get it, or a slightly rusty bristle from a wire brush wont tin and stick.
     
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  11. rambomhtri

    Thread Starter Member

    Nov 9, 2015
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    OK, I'll try it tomorrow, or this friday may be.

    One question:
    What do you guys do with the solder you remove?
    Do you re-use it?
    Do you bin it? Since it has lead, I don't think it should go to a regular bin container...
     
  12. ian field

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    Oct 27, 2012
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    The dross you empty out of the solder sucker will ruin the tip on the iron.
     
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  13. rambomhtri

    Thread Starter Member

    Nov 9, 2015
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    Then what do you do with it?
     
  14. spinnaker

    AAC Fanatic!

    Oct 29, 2009
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    Toss it. There is such a small amount of lead I would not worry about it. If you are really worried then save it up and take it to a hazardous waste disposal every 10 or 20 years. :)
     
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  15. rambomhtri

    Thread Starter Member

    Nov 9, 2015
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    38-40% of lead is a "small amount"? :eek:
    I don't think so... To me, it sounds like BIG numbers.
     
  16. spinnaker

    AAC Fanatic!

    Oct 29, 2009
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    If you are doing this desoldering exercise just for practice then that is wonderful. But it is is just the parts you want then it is much easier ordering new. Those connectors can be had on eBay for really cheap.
     
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  17. spinnaker

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    But the amount of solder you are removing is. You probably won't be desoldering all that much unless you start a repair business. I don't think I have ever emptied my new solder sucker I bought a few years ago.
     
    Last edited: Nov 18, 2015
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  18. MrAl

    Well-Known Member

    Jun 17, 2014
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    Hello,

    A trick you can use with these more stubborn parts is to work on ONE pin at a time, and that may include the body pins also...one at a time. If you only have two pins to unsolder you can usually heat one up at a time and pry one leg out a little, then go back to the other leg, then back to the previous leg, etc., until the part comes out. But when there are more than two pins it gets harder, so a trick is to detach all the pins from the main body of the part and then heat up and easily remove each pin one by one.

    Detaching could mean simply cutting the pins off the body, all of them, one by one with a flush cutting wire cutter, or it could mean grinding the part with a small grinding wheel such as on a Dremel, and then cutting the pins or grinding them off the main body.
    Once the pins are detached from the main body they unsolder very easily because they are small and heat up fast and they come out easy unless they were jammed into a hole that was too small in the first place.

    You can use this trick with IC chips too, DIP or SMD parts. Of course you cant use the part after that but usually it's the board that is more important.

    Good luck :)
     
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  19. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
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    In my experience unheated 'solder suckers' are a waste of time, space and patience -- Please consider a desoldering iron or flux-wetted desoldering braid (don't count on 'pre-fluxed' braid)...
    Please be advised that the connector may be 'adhesively bonded' to the PCB (in which case a 'heat gun' may facilitate removal)

    Best regards and good luck!:)
    HP
     
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  20. spinnaker

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    Oct 29, 2009
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    And if you use the heat gun / tapping method I mentioned then most of the solder will remain adhered tot he board. Then you can dispose of the whole board at hazardous waste (assuming you were salvaging parts).
     
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