schriste@uceng.UC.EDU (steven v christensen) (08/08/89)
Dear net.land I recently came into possession of about 10 IBM PC-type boards, which are chok' full of nice standard TTL and CMOS chips (74xx and the like) that I would LOVE to de-solder and use in my own projects. My problem is that I have a little whimpy soldering iron, and I am not quite quick enough to heat all the pins up at the same time to remove the chip. I tried a solder-sucker, but that leaves just enough solder to firmly hold the chip. It would seem to me that I need some attachment to the iron which would sit on all the pins and heat them all to let me remove the chips. Does one of these gizmo's exist? I have scoured the catalogs I have and have not found one. Anyone have any suggestions? Thanks, Steven Christensen schriste@uceng.uc.edu -- Steven V. Christensen U.C. College of Eng. schriste@uceng.uc.edu
jimsp@donk.UUCP (jimsp) (08/10/89)
In article <1846@uceng.UC.EDU> schriste@uceng.UC.EDU (steven v christensen) writes: > I recently came into possession of about 10 IBM PC-type >boards, which are chok' full of nice standard TTL and CMOS chips >(74xx and the like) that I would LOVE to de-solder and use in >my own projects. I picked up this trick from my high school shop instructor years ago. If all you want are the chips, and the board is expendable. put the pc board in a vice, grab the chip with pliers, and heat the back side of the board with a propane torch. CAUTION THE FUMES FROM THE BOARD ARE TOXIC DO THIS IN A WELL VENTILLATED AREA!!!!!!.
wek@point.UUCP (Bill Kuykendall) (08/11/89)
A simpler solution is to destroy the board with a pair of dykes and clean the legs off after the fact. The torch trick sounds a little radical for heat sensitive devices (not to mention human breathing apparatus).
ritchie@hpldola.HP.COM (Dave Ritchie) (08/14/89)
>A simpler solution is to destroy the board with a pair of dykes and clean >the legs off after the fact. The torch trick sounds a little radical for >heat sensitive devices (not to mention human breathing apparatus). >---------- A better way is to place the iron tip on the leads on the top side of the board and use an solder sucker (the blue plastic one from Radio Shack is good) to remove the solder from the holes on the bottom. By applying heat from the top and using the iron to bend the pins away from the sides of the holes, you can remove most any IC (the problem being that if you heat the hole on a pin hooked to a ground/power plane, it takes incredable amounts of heat to free the pin - heating the pin from the top, along with placing pressure on the pin to center it in the hole causes the solder to flow away from the *pin*, producting the desired result). This method caused little or no damage to the board or the IC. Dave Ritchie
hardin@hpindda.HP.COM (John Hardin) (08/14/89)
schriste@uceng.UC.EDU (steven v christensen) writes: > I recently came into possession of about 10 IBM PC-type >boards, which are chok' full of nice standard TTL and CMOS chips >(74xx and the like) that I would LOVE to de-solder and use in >my own projects. > > My problem is that I have a little whimpy soldering iron, and >I am not quite quick enough to heat all the pins up at the same time to >remove the chip. I tried a solder-sucker, but that leaves just enough >solder to firmly hold the chip. ---------- Whenever I've done this, the solder sucker never gets enough solder out to just lift the chip away, but a little sideways wiggling of each pin from the back side of the board with a needle nose pliars will break each pin free of the little remaining solder. You can then lift the chip free. Much simpler than a special device to heat all the pins at once. Good luck. John Hardin hardin%hpindgh@hplabs.hp.com --------
davidsen@sungod.crd.ge.com (ody) (08/14/89)
In article <[1427.2]comp.ibmpc;1@point.UUCP> wek@point.UUCP (Bill Kuykendall) writes: | A simpler solution is to destroy the board with a pair of dykes and clean | the legs off after the fact. The torch trick sounds a little radical for | heat sensitive devices (not to mention human breathing apparatus). We used to empty boards by heating with a torch and slapping the board down against the rim of a 55 gal drum. The results were usually 80% still good. As you say, ventilation is important when doing this. bill davidsen (davidsen@crdos1.crd.GE.COM) {uunet | philabs}!crdgw1!crdos1!davidsen "Stupidity, like virtue, is its own reward" -me
genemans@eleazar.dartmouth.edu (Jan Genemans) (08/14/89)
In article <[1427.2]comp.ibmpc;1@point.UUCP> wek@point.UUCP (Bill Kuykendall) writes: >A simpler solution is to destroy the board with a pair of dykes and clean >the legs off after the fact. The torch trick sounds a little radical for >heat sensitive devices (not to mention human breathing apparatus). What if you have a board with an 8086 processor that is soldered on the board. I want to remove this chip and replace it with a V30. Is there an easy way of doing this without destroying the board with dykes or a blow torch? / Jan Genemans | USENET: Jan.Genemans@Dartmouth.edu \ / ADP | UUCP: ...!dartvax!mac.dartmouth.edu!Jan.Genemans \ \ U.S.M.M.A. +---------+------------------------------------------/ \ Kings Point, NY 11024 | "Live long and prosper" -Spock /
malloy@nprdc.arpa (Sean Malloy) (08/15/89)
In article <15014@dartvax.Dartmouth.EDU> genemans@mac.dartmouth.edu (Jan Genemans) writes: >In article <[1427.2]comp.ibmpc;1@point.UUCP> wek@point.UUCP (Bill Kuykendall) writes: >>A simpler solution is to destroy the board with a pair of dykes and clean >>the legs off after the fact. The torch trick sounds a little radical for >>heat sensitive devices (not to mention human breathing apparatus). > >What if you have a board with an 8086 processor that is soldered on the board. >I want to remove this chip and replace it with a V30. Is there an easy way of >doing this without destroying the board with dykes or a blow torch? If you're not worried about having the 8086 around to use afterward, you can just clip the legs off the 8086, toss the DIP case, and take the legs off one by one. Alternatively, the method I used to replace the DMA chip on an old ITT Xtra was to go after each pin with a soldering iron, a solder sucker (one of the spring-loaded widgets that is sort of a hand-cocked reverse syringe), and a roll of solder wick (braided copper wire that you push onto the joint with the hot iron to wick off solder). Once all but the unavoidable minimum of solder remains on the pins, you use a small cross-shaped piece of sheet steel with two arms bent up and around the soldering iron tip (I understand you can buy these as screw-in tips for some irons, but I had the scrap) to heat the bottom of a row of pins while you press on the row with the iron and gently pull up on the same edge of the chip from the other side of the board. The solder will soften and allow you to pull the pins out of one row of holes (some of the holes may fill with solder, but the sucker or wick can take care of that. You repeat the process on the other side, and you will have removed the chip. The very next thing you do is solder a socket back in in its place, so you don't have to do this again. The whole process should take about half an hour. Sean Malloy | "The proton absorbs a photon Navy Personnel Research & Development Center | and emits two morons, a San Diego, CA 92152-6800 | lepton, a boson, and a malloy@nprdc.navy.mil | boson's mate. Why did I ever | take high-energy physics?"
hoang@rex.cs.tulane.edu (Dzung Hoang) (08/15/89)
I remember seeing special tips and tools for desoldering 16-18 pin DIPS
a few years back. The tip is basically shaped like an IC socket with slots
for the pins. One uses the tip to heat all pins simultaneously and then
remove the IC from the board using a spring clip on the other side.
I haven't been able to find these tools recently. Does anyone know a
source for these?
Dzung Hoang
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hoang@comus.cs.tulane.edu hoang@rex.cs.tulane.edu
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-----------------------------------------------------------------------------keithe@tekgvs.LABS.TEK.COM (Keith Ericson) (08/15/89)
>A simpler solution is to destroy the board with a pair of dykes and clean >the legs off after the fact. The torch trick sounds a little radical for >heat sensitive devices (not to mention human breathing apparatus). We've got soldering iron tips around here that are made to unsolder up to 16-pin DIPS. It replaces a standard (Weller?) copper tip with a block that is the size of a 16-pin DIP package and hs little indentations where the legs stick thru the board. My guess is that they might be available at larger electronic supply stores. kEITHe
chip@vector.Dallas.TX.US (Chip Rosenthal) (08/15/89)
genemans@mac.dartmouth.edu (Jan Genemans) writes: >What if you have a board with an 8086 processor that is soldered on the board. >I want to remove this chip and replace it with a V30. Is there an easy way of >doing this without destroying the board with dykes or a blow torch? That is a *totally* different problem. Save-board/trash-chip is easy vs save-chip/trash-board. Cut all the leads off the chip and desolder them one by one. However, if you have to ask, you probably shouldn't be trying it. -- Chip Rosenthal / chip@vector.Dallas.TX.US / Dallas Semiconductor / 214-450-5337 "I wish you'd put that starvation box down and go to bed" - Albert Collins' Mom
harper@artemis.uucp (David Harper) (08/15/89)
In article <15014@dartvax.Dartmouth.EDU> genemans@mac.dartmouth.edu (Jan Genemans) writes: >In article <[1427.2]comp.ibmpc;1@point.UUCP> wek@point.UUCP (Bill Kuykendall) writes: >>A simpler solution is to destroy the board with a pair of dykes and clean >>the legs off after the fact. The torch trick sounds a little radical for >>heat sensitive devices (not to mention human breathing apparatus). > >What if you have a board with an 8086 processor that is soldered on the board. >I want to remove this chip and replace it with a V30. Is there an easy way of >doing this without destroying the board with dykes or a blow torch? > > > / Jan Genemans | USENET: Jan.Genemans@Dartmouth.edu \ >/ ADP | UUCP: ...!dartvax!mac.dartmouth.edu!Jan.Genemans \ >\ U.S.M.M.A. +---------+------------------------------------------/ > \ Kings Point, NY 11024 | "Live long and prosper" -Spock / Removing soldered in chips from a board is always a pain. The best way to do it is to use a Pace desoldering station, assuming you have access to one. If not, a GOOD solder sucker should also work but will probably take you a little longer. If you are not interested in saving the old 8086, the fastest way (and probably the best way for the motherboard itself) is to take a pair of dykes and clip each of the pins from the 8086. These can then be easily removed from the motherboard by heating the back side of the motherboard with a low wattage iron (15W-25W) while holding onto the pin on the front side with a pair of needle nose pliers. Once all of the pins are out you can go back over the board with the solder sucker and easily clean out each of the holes. You might also consider installing a socket for next time :). BTW, I have used the torch trick in the past to remove wire wrap sockets that were soldered into prototype boards and it worked quite well for me. Assuming it's done from the back of the board it should not pose any problems for heat sensitive devices as long as you don't linger too long on any given device. Dave Harper - Convex Computer Corp. E-mail address: 3000 Waterview Pky. Richardson, TX 75081 harper@convex.COM (214) 497-4525 (W) (214) 727-4206 (H) Dave Harper - Convex Computer Corp. E-mail address: 3000 Waterview Pky. Richardson, TX 75081 harper@convex.COM (214) 497-4525 (W) (214) 727-4206 (H)
fredex@cg-atla.UUCP (Fred Smith) (08/15/89)
In article <15014@dartvax.Dartmouth.EDU> genemans@mac.dartmouth.edu (Jan Genemans) writes: > >What if you have a board with an 8086 processor that is soldered on the board. >I want to remove this chip and replace it with a V30. Is there an easy way of >doing this without destroying the board with dykes or a blow torch? ------------------------ Yeah! If you don't mind trashing the original chip, just cut the legs off it from the TOP side of the board then carefully de-solder each leg individually. Then be sure to install a socket in the holes before putting in the new chip so you won't have to go thru this again if you change your mind. Since 8086's are inexpensive and V30s are too, trashing the chip shouldn't be all that painful! Fred