Announcement

Collapse
No announcement yet.

Clearing plugged holes

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Clearing plugged holes

    I'm looking for advice from anyone who's dealt with this problem before. I have a computer video card with 4 blown capacitors. Last night I desoldered the capacitors, but most of the holes (vias) are still plugged with solder and I've been unable to clear them. It's this darn lead-free solder combined with a multilayer board and large ground planes. Here's what I tried last night.

    1. Holding my iron on the via to melt the solder, then hitting it with a Soldapullt solder sucker.

    2. Using desolder wick to suck up the solder.

    3. Adding fresh leaded solder and/or liquid flux then trying the solder sucker and wick again.


    The holes are still plugged. I have considered several options, anyone know which would be the best (most likely to succeed with lowest chance of damaging the board)?

    1. Turn up the heat. I keep my Hakko solder station set around 350 - 400 C, I could turn it up to deliver more heat.

    2. I have a heat gun I could use. This might deliver more heat to a larger part of the board thus melting the solder.

    3. Try again with solder wick, perhaps turning up the heat and/or using more flux.

    4. Try heating the joint and poking a thin piece of metal through, like a small safety pin.

    5. Purchase a new tip for my soldering station. Something like the T18-BL (http://www.hakkousa.com/AHPDirect/images/T18-BL.jpg). With a thin sharp point it might be able to reach into the hole (although I'm skeptical it could deliver enough heat all on it's own).

    6. I have some ChipQuik low temperature solder I could try melting in.

    7. Heat the board up with a hot iron and try using the solder sucker from the opposite side. Difficult to do with only two hands.

    8. Use an extremely small drill bit and my drill press to literally drill out the solder. I estimate a 1/64" drill bit would be necessary.


    Any advice?

    If I can't get the holes clear I have a backup plan. This particular board has both through-holes and surface mount pads for each capacitor. So I could switch to surface mount electrolytics. To me this is plan-B because A) I've already purchased the through-hole capacitors and B) I'm likely to have the same trouble melting solder to the big surface mount pads.
    Last edited by Freezer; 01-24-2014, 04:22 PM.

    #2
    Re: Clearing plugged holes

    I used stainless steel sharp dental tool pick pushing on the opposite side of where you put the soldering iron tip on the hole. You should add lead solder to the hole, 60W IRON with 2~3mm wide tip will help a lot.
    Never stop learning
    Basic LCD TV and Monitor troubleshooting guides.
    http://www.badcaps.net/forum/showthr...956#post305956

    Voltage Regulator (LDO) testing:
    http://www.badcaps.net/forum/showthr...999#post300999

    Inverter testing using old CFL:
    http://www.badcaps.net/forum/showthr...er+testing+cfl

    Tear down pictures : Hit the ">" Show Albums and stories" on the left side
    http://s807.photobucket.com/user/budm/library/

    TV Factory reset codes listing:
    http://www.badcaps.net/forum/showthread.php?t=24809

    Comment


      #3
      Re: Clearing plugged holes

      Next time, just gently twist the capacitors back and forth 20-30 times until the leads weaken and they break. Then, add blobs of leaded solder on the other side of the board and while solder is hot, grab the remainder of the leads on the other side (a few mm of wire) with some tweazers and push them through. The lead will get out along with the solder blob.

      I also have stainless stell needles, they're not the medical ones but that cheap ebay ones that look like they're home made. They work.

      Here's what I'm talking about : http://www.ebay.com/itm/8pcs-Hollow-...item5adfb9a6e4

      Some people use compressed air.. stick a syringe needle on top of a can of compressed air, put the needle on the component side, heat the solder.. push air ... the solder on bottom side will be ejected all over the place (so do it on top of a sheet of paper or something).
      If you want to try this method, i don't know if you guys have free access to needles, here any pharmacy gives syringes and needles no questions asked. Maybe go to a vet and explain you need needles for electronics if you have problems sourcing.

      Comment


        #4
        Re: Clearing plugged holes

        http://www.testequipmentdepot.com/pr...FQdBQgodgRYADA
        http://www.amazon.com/SE-Probe-Set-5..._sim_sbs_hi_10
        http://www.harborfreight.com/5-piece...-set-1816.html
        Last edited by budm; 01-24-2014, 05:32 PM.
        Never stop learning
        Basic LCD TV and Monitor troubleshooting guides.
        http://www.badcaps.net/forum/showthr...956#post305956

        Voltage Regulator (LDO) testing:
        http://www.badcaps.net/forum/showthr...999#post300999

        Inverter testing using old CFL:
        http://www.badcaps.net/forum/showthr...er+testing+cfl

        Tear down pictures : Hit the ">" Show Albums and stories" on the left side
        http://s807.photobucket.com/user/budm/library/

        TV Factory reset codes listing:
        http://www.badcaps.net/forum/showthread.php?t=24809

        Comment


          #5
          Re: Clearing plugged holes

          Shown brave and buy a 90W soldering station, this would keel all holes open at 95%.
          A modern SMT hot Air rework station it would handle the other 5%.

          Comment


            #6
            Re: Clearing plugged holes

            Originally posted by Freezer View Post
            I'm looking for advice from anyone who's dealt with this problem before. I have a computer video card with 4 blown capacitors. Last night I desoldered the capacitors, but most of the holes (vias) are still plugged with solder and I've been unable to clear them. It's this darn lead-free solder combined with a multilayer board and large ground planes. Here's what I tried last night.

            1. Holding my iron on the via to melt the solder, then hitting it with a Soldapullt solder sucker.

            2. Using desolder wick to suck up the solder.

            3. Adding fresh leaded solder and/or liquid flux then trying the solder sucker and wick again.




            The holes are still plugged. I have considered several options, anyone know which would be the best (most likely to succeed with lowest chance of damaging the board)?

            1. Turn up the heat. I keep my Hakko solder station set around 350 - 400 C, I could turn it up to deliver more heat.

            2. I have a heat gun I could use. This might deliver more heat to a larger part of the board thus melting the solder.

            3. Try again with solder wick, perhaps turning up the heat and/or using more flux.

            4. Try heating the joint and poking a thin piece of metal through, like a small safety pin.

            5. Purchase a new tip for my soldering station. Something like the T18-BL (http://www.hakkousa.com/AHPDirect/images/T18-BL.jpg). With a thin sharp point it might be able to reach into the hole (although I'm skeptical it could deliver enough heat all on it's own).

            6. I have some ChipQuik low temperature solder I could try melting in.

            7. Heat the board up with a hot iron and try using the solder sucker from the opposite side. Difficult to do with only two hands.

            8. Use an extremely small drill bit and my drill press to literally drill out the solder. I estimate a 1/64" drill bit would be necessary.


            Any advice?

            If I can't get the holes clear I have a backup plan. This particular board has both through-holes and surface mount pads for each capacitor. So I could switch to surface mount electrolytics. To me this is plan-B because A) I've already purchased the through-hole capacitors and B) I'm likely to have the same trouble melting solder to the big surface mount pads.

            You could always offer up the caps to the holes and heat the solder from underneath when it melts shove the legs through.

            Comment


              #7
              Re: Clearing plugged holes

              Originally posted by Freezer View Post
              4. Try heating the joint and poking a thin piece of metal through, like a small safety pin.
              That's the method I use and recommend. In my case, I use a cork board pin/tack. I DON'T use it to clear the holes all the way, just enough to make indentations where the holes are. Then, I pre-cut the leads on the caps to proper length, position the cap's legs in the indentations, and "walk" the cap back in using this method:

              https://www.badcaps.net/forum/showpo...7&postcount=23
              (it's the same method I use for removing caps)

              Works on any board - even Xbox 360's, which have insanely thick Vcc planes.

              Just out of curiosity, what brand/model video card are you recapping?

              Comment


                #8
                Re: Clearing plugged holes

                Success!

                Most seem to suggest poking the holes free with something like a dental pick. I don't have a dental pick (although I'm definitely going to add some to my tool box). But I found a sewing pin was just the right size for the holes. Using my iron I heated up the joint and once melted I slowly worked the pin through the hole. It took between 15 and 30 seconds of heating per hole. Once the pin was through I kept the pin moving as I removed the iron (to prevent the solder from bonding to the pin).

                Thanks to all for the suggestions.

                popeye:
                I considered trying to push the new caps through while melting the existing solder. In fact, I've tried that before on another board. But I found I was more likely to bend the leads on the cap by push before the hole was ready to accept.

                momaka:
                The video card is an XFX brand w/ the nVidia 8600 GT chipset. An older card and may not have been worth the effort. But to me, repairing is half the fun.

                Comment


                  #9
                  Re: Clearing plugged holes

                  Originally posted by Kiriakos GR View Post
                  Shown brave and buy a 90W soldering station, this would keel all holes open at 95%.
                  A modern SMT hot Air rework station it would handle the other 5%.
                  I was going to say hot air as well. I use a GQ 5200 regularly. Not needed as much with 2-leg components but its a life/time saver if you're desoldering anything more than 2 legs as the entire area is heated for easy removal (jacks, multi-leg ic chips). Once the solder is flowing you simply remove the chip, keep the heat and suck the excess solder out.

                  Maybe not needed if you're only doing it as a small hobby, but definitely worth it (especially at $100) if you do it semi-regularly.

                  Comment


                    #10
                    Re: Clearing plugged holes

                    i dont think there is an easy way to do this,i had problems with motherboards before,and they are a bear.
                    what happens its that you heat up the area where the hole is so much ,that sooner or later you will lift the pad.
                    i didnt think about the drill method,it seems that may work,but remember the different layers are connected with each other inside the pcboard and there is a chance one layer may not get connected when you drill thru the hole and tear the internal connection betwwen the layers,i think if you can get a drill smaller than the hole,so you dont touch the wall of the hole that it may work.good luck.please post any results if you decide to do that .
                    i am going to do it myself as soon as i found one of my boards that i have somewhere with the same problem.and a relly small drill bit.
                    i am sorry bud,i sent this reply to you instead of freezer ,who has the problem with the plugged up holes on the pcbs.
                    your reply sounds very good,i am going to try it.i guess the stailess steel in wont get soldered to the hole right?.i have put just plain wires and that does not work,but i will try anything to get the job done.thanks bud.
                    Last edited by aortiz; 02-17-2014, 12:10 PM.

                    Comment


                      #11
                      Re: Clearing plugged holes

                      On the rare occasions when I have used a drill I would put the drill in a pin vise and gently drill by hand. I would not recommend using any power tool to drill out the solder.

                      I have also had good luck with using the solder sucker on the side of the board opposite the soldering iron. I put the board in a vise so that both hands are free to work the soldering iron and solder sucker. I always add new solder to the hole before clearing it this way.

                      Comment


                        #12
                        Re: Clearing plugged holes

                        I use a cutting torch tip cleaning wire. There are several size cleaning wires from pin size to fine wire size. You should be able to find one about anywhere they sell welding and cutting torchs. It has always worked for me.

                        Comment

                        Working...
                        X