How to Desolder
Locate the terminals for the component to be removed., Clean the terminals., Attach a heat sink., Clean your soldering iron as it heats., Push down on the desoldering pump., Heat the old solder with your soldering iron., Vacuum up the melted...
Step-by-Step Guide
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Step 1: Locate the terminals for the component to be removed.
A desoldering pump, also called a solder sucker, vacuums up melted solder to separate soldered components from a circuit board.
Thoroughly examine both sides of the board to isolate the specific spots holding each component in place.
The desoldering pump works best for through-hole connections.
You can use it on surface-mounted devices as well, but it is less effective.That said, it's one of the cheapest options.
You can easily ruin a circuit board by accidentally separating the board layers during the desoldering process.
Ensure that you only desolder the exact pins you need to remove a faulty component. -
Step 2: Clean the terminals.
Using isopropyl alcohol on a toothbrush, gently clean the terminals of the component(s) to be removed.Ensure that you clean only the terminals on the soldered side of the board and not anything on the component side. , The heat from the soldering iron can damage sensitive components such as integrated circuits or transistors.
To dissipate some of the heat, clip a metal alligator clip between the component and the terminal you plan to desolder., Turn your soldering iron on and let it heat up for about three minutes.
Using a wet sponge make quick passes from base to tip over your soldering iron to clean it.You may see a tiny bit of smoke as you pass the sponge, but it’s just from the moisture in the sponge. , Press the end of the pump until it clicks into place.
This compresses a spring, and latches it in the depressed position. , Using the tip of your soldering iron, heat the old solder until it melts.
You can push the terminal with the soldering iron tip at the same time to help free the component as the old solder melts.Use an old soldering iron if you have one, since pushing with the iron can wear the iron down. , Touch the tip of the desoldering pump to the solder pad and melted solder, without applying pressure.Release the spring (usually by pushing a button on the side) and the piston will shoot back quickly.
This creates a vacuum which pulls the melted solder up into the pump.The tip of the pump may melt a little during use.
Most pumps either have replaceable tips or are cheap to begin with, but you can try to reduce the damage by pausing for a moment after melting the solder.
Melted solder can harden again quickly.
Work with only one terminal at a time.
For the greatest efficiency, hold the soldering iron in one hand and keep the desoldering pump ready in the other. , After each use, push the pump down again over a trash can to re-arm it and to clear out the solder.
If you leave the old solder inside, it can leak back out as you go to vacuum the next terminal. , It often takes multiple passes with the soldering iron and pump before the component is free.
If you're not making progress after a few tries, try any or all of these adjustments:
Apply flux first to help the melted solder flow.
Melt a little new solder to mix in with the old, hardened solder.For through-hole connections, use the tip of the soldering iron to gently wiggle the terminal from side to side.
This breaks the connection to the sides of the hole., You may notice brown resin stuck around the solder pad, since this can melt when heated.
You can remove this with a commercial resin cleaner, or scrape it away very carefully with a small, flat-head screwdriver or steel wool.
Finish by cleaning the area with a toothbrush dampened with isopropyl alcohol.Sometimes, the pressure from the iron or pump will shift the solder pad slightly.
It should still work as long as the traces connecting the pad to other components are still intact.
If the traces are broken, you will need to solder on new ones.If there are still traces of solder on the pad, it's easy to pick these up using a desoldering braid, described below. -
Step 3: Attach a heat sink.
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Step 4: Clean your soldering iron as it heats.
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Step 5: Push down on the desoldering pump.
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Step 6: Heat the old solder with your soldering iron.
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Step 7: Vacuum up the melted solder.
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Step 8: Empty the desoldering pump into the trash.
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Step 9: Troubleshoot difficult connections.
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Step 10: Clean the board.
Detailed Guide
A desoldering pump, also called a solder sucker, vacuums up melted solder to separate soldered components from a circuit board.
Thoroughly examine both sides of the board to isolate the specific spots holding each component in place.
The desoldering pump works best for through-hole connections.
You can use it on surface-mounted devices as well, but it is less effective.That said, it's one of the cheapest options.
You can easily ruin a circuit board by accidentally separating the board layers during the desoldering process.
Ensure that you only desolder the exact pins you need to remove a faulty component.
Using isopropyl alcohol on a toothbrush, gently clean the terminals of the component(s) to be removed.Ensure that you clean only the terminals on the soldered side of the board and not anything on the component side. , The heat from the soldering iron can damage sensitive components such as integrated circuits or transistors.
To dissipate some of the heat, clip a metal alligator clip between the component and the terminal you plan to desolder., Turn your soldering iron on and let it heat up for about three minutes.
Using a wet sponge make quick passes from base to tip over your soldering iron to clean it.You may see a tiny bit of smoke as you pass the sponge, but it’s just from the moisture in the sponge. , Press the end of the pump until it clicks into place.
This compresses a spring, and latches it in the depressed position. , Using the tip of your soldering iron, heat the old solder until it melts.
You can push the terminal with the soldering iron tip at the same time to help free the component as the old solder melts.Use an old soldering iron if you have one, since pushing with the iron can wear the iron down. , Touch the tip of the desoldering pump to the solder pad and melted solder, without applying pressure.Release the spring (usually by pushing a button on the side) and the piston will shoot back quickly.
This creates a vacuum which pulls the melted solder up into the pump.The tip of the pump may melt a little during use.
Most pumps either have replaceable tips or are cheap to begin with, but you can try to reduce the damage by pausing for a moment after melting the solder.
Melted solder can harden again quickly.
Work with only one terminal at a time.
For the greatest efficiency, hold the soldering iron in one hand and keep the desoldering pump ready in the other. , After each use, push the pump down again over a trash can to re-arm it and to clear out the solder.
If you leave the old solder inside, it can leak back out as you go to vacuum the next terminal. , It often takes multiple passes with the soldering iron and pump before the component is free.
If you're not making progress after a few tries, try any or all of these adjustments:
Apply flux first to help the melted solder flow.
Melt a little new solder to mix in with the old, hardened solder.For through-hole connections, use the tip of the soldering iron to gently wiggle the terminal from side to side.
This breaks the connection to the sides of the hole., You may notice brown resin stuck around the solder pad, since this can melt when heated.
You can remove this with a commercial resin cleaner, or scrape it away very carefully with a small, flat-head screwdriver or steel wool.
Finish by cleaning the area with a toothbrush dampened with isopropyl alcohol.Sometimes, the pressure from the iron or pump will shift the solder pad slightly.
It should still work as long as the traces connecting the pad to other components are still intact.
If the traces are broken, you will need to solder on new ones.If there are still traces of solder on the pad, it's easy to pick these up using a desoldering braid, described below.
About the Author
Brian Parker
Specializes in breaking down complex crafts topics into simple steps.
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