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After years of being thrown in travel bags, tripped over, and quite literally dragged through the dirt many laptop power cords succumb to the abuse and begin to fray.  Eventually the fraying cord will break apart and no longer power your laptop.  Here's how to rescue your power cord from the landfill, and save yourself a few bucks along the way!
 
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Step 1: Tools Required

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You will need:

1. Vise (or other means for securely holding your power "brick")
2. Soldering Iron (and solder)
3. Multimeter (not strictly needed, but its always better to check your work)
4. Flathead Screwdriver
5. Wire Cutter/Stripper
6. Utility Knife
7. Hot Glue Gun
8. Super Glue
9. Heat Shrink Tubing or Electrical Tape (not pictured)

Step 2: Get Started!

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Begin by ensuring that your power cord is disconnected from both your laptop and from the wall outlet.  From this point forward I will refer to the end that connects to your laptop as the "low voltage cable" and the end that connects to the wall as the "high voltage cable".

Now for the disclaimer....

Warning! Throughout the remainder of this repair we will be exposed to circuitry that poses a shock risk. DO NOT touch components or their leads unless you are absolutely sure you understand what you are handling. This is a simple repair that does NOT require even a moderate electronics knowledge you only need to be able to solder.  All the risk is in touching components/contacts incidentally or intentionally that you are not instructed to touch. Never try to repair a power supply that is in service or connected to any source (i.e. a laptop or wall power). Proceed at your own risk.

Lets continue by unplugging the high voltage cable from the power brick (if your power supply allows for this), and by making a single cut through the low voltage cable near the fraying cord. Ensure the fraying portion of the low voltage cable is left attached to the power brick so we can remove it.

Set the high & low voltage cables to the side.  We will need them later.

Step 3: Open the Power Brick

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Depending on the manufacturer power bricks are held closed in a variety of ways.  Some have screws, some are glued, some have locking tabs, and some are even welded.  Use your discretion as far as how to open your power brick, but the majority I have encountered were either glued or welded.

To open a glued or welded power brick, begin by securing it in a vise or with a clamp. Now, using a sharp utility knife make repeated cuts along the seam until you have cut through the outer plastic shell.  It's important to stop cutting as soon as you are through the plastic so as to not damage the electronics.  Take your time.  Patience pays off big on this step.  I typically spend at least 15 minutes carefully cutting through the entire seam. I focus on one side of the brick at a time.  Also, I have never had to cut around the low voltage cable or the high voltage cable connector.  Just stick to cutting the long, horizontal seam on all 4 sides.

Step 4: Remove the Enclosure

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Now that you have cut through the entire seam, use a flat screwdriver to pry off the top half of the plastic enclosure from the power brick.  If you were patient and took your time cutting this step should be easy. 

With the top removed, separate the bottom of the plastic enclosure from the power brick.

Set the entire plastic enclosure to the side for later.

You should be left with a bare power brick.

Step 5: Desolder the Low Voltage Cable

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Use your soldering iron to desolder the remaining piece of low voltage cable from the power brick. There should be 2 connections to desolder. Remove them 1 at a time and be sure to note which color wire goes where. For this example the connections are circled in yellow.  Be careful to not touch anything else!

If you are particularly driven you can attempt to salvage the strain relief from the piece of low voltage cable we just removed by carefully cutting along its long axis with a utility knife.  If you do reclaim it, don't forget to install it on the good low voltage cable before closing the plastic power brick housing. 

Step 6: Solder in Low Voltage Cable

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Find the good section of low voltage cable that we set aside in an earlier step and strip about 1" of the cable jacket from the inner conductors.  The easiest way to remove the jacket is to carefully cut around the circumference of the cable with a utility knife then pull the jacket off and discard. 

Use your wire strippers and strip away 1/2" of the insulation from the inner, insulated conductor.  It's likely around 16 AWG wire.

For this low voltage cable there is only 1 insulated conductor.  If both of  your conductors are insulated strip 1/2" from the second conductor as well.  Since our second conductor is un-insulated, we will insulate it using a 1/2" piece of heat shrink tubing or electrical tape.

Finally we can solder the good section of low voltage cable back into its contacts on the power brick.  Be sure to connect the correct wire from the cable to the correct pad on the power brick.

Step 7: Assemble the Enclosure

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Place the power brick into the bottom of its plastic enclosure.  Apply a bead of super glue around the entire seam that we previously cut apart, and firmly seat the top half of the plastic enclosure in place over the power brick.  It may be necessary to clamp the enclosure until the glue has fully cured.

Step 8: Add Strain Relief

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Whether you salvaged the factory strain relief or not use a hot glue gun and a little creativity to fashion some strain relief of your own!  Generally speaking, the beefier the better, but make sure your masterpiece is securely anchored to the power brick enclosure.

Step 9: Test and Use

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If you removed your high voltage cable, reattach it now and plug it into the wall outlet.

Use your multimeter to check the voltage of the concentric power plug at the end of the low voltage cable.  You should get a reading near the nominal voltage rating of your Power Brick.  For this example the nominal rating was 19V.  To find your nominal voltage it should be listed in the fine print on the back of your power brick's plastic enclosure.

Congratulations, it's ready to use! You have successfully rescued the world from unnecessary electronic waste, and saved yourself a few bucks along the way!
jamescmarch made it!3 months ago

Thanks. Worked like a charm (I am no stranger to soldering or a multimeter, though). Until I get some super glue, I've taped the box closed with electrical tape.

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Forgot to say that I also salvaged the old strain relief by pulling out the old cord and reaming it with a drill bit the same size as the cord. I put a wind of electrical tape around the soldered end of the cord and pulled the cord into the old strain relief to give the necessary tension/friction.

mocupa1 year ago
Thnx very much, I've almost buy a new one.
Nice tutorial.
JewelA1 mocupa6 months ago

Its pretty dangerous. Did it work for you afterward? I expect it did. My hp power didn't work before and i didn't repire it.I bough a new one from UKbatteryfast.It is a great source for OEM chargers if you can find them.

Witweed7 months ago
My high-voltage cable port sparked. How can I fix it?
NathanL18 months ago

this is not my problem i plug in the charger bu the light won't come on there are no cut wires and the power cord works just fine.

KROKKENOSTER9 months ago

What I have found through the years working with co-ax is I do the cutting of the insulation with a chisel shaped bit soldering iron. If you do use any other method, the wire strands get damaged no matter how careful you are.Okay the cut may not appear as neat but I had more wires and this gave a longer lasting joint or termination.

50011201 year ago
thank
sage7101 year ago
have you tried repairing the end that connects to the laptop itself? That is the end I need to repair. Good instructions!
EE-Dan (author)  sage7101 year ago
Repairing the barrel connector end could prove to be a bit more difficult. The simplest solution would be to purchase a replacement barrel connector, cut off the existing barrel connector, and attach the new one. However, in my experience most manufacturers use proprietary barrel connectors (i.e. non-standard sizes). If you have some calipers you can measure your plug and see if its size matches those available from digi-key here: http://bit.ly/18lThRx

To perform this fix you will definitely need to have a multi-meter to ensure that the proper wire in the low voltage cable jacket is connected to the proper contact on the barrel plug. Just make reference measurements on the existing barrel plug and ensure you wire the new one the same way. Be sure to double check your work by testing the voltage and polarity of the barrel plug after the repair and before plugging it into the laptop.

Hope this helps!


kdjo1 year ago
Hola desde Guatemala, para el paso 8, se puede usar el protector de cable que tiene el adaptador, simplemente se le sacan los cables dañados, con una broca de 3/16 se perfora dentro del protector, sacando el forro viejo y se mete el cable por ahi asegurandolo dentro del cargador con un cincho (Cable Tie) y luego cerrar el cargador.
Hello from Guatemala, for step 8, you can use the shield cable with the adapter, simply take the wires is damaged, with a bit of 3/16 is drilled into the protector, removing the old liner and gets the there securing cable inside the charger with a girdle (Cable Tie) and then close the magazine. Google Translator!
mocupa kdjo1 year ago
Buena idea.
Concordo com o passo-a-passo, menos com o final. Esse acabamento com a cola ficou horrível. Eu já fiz alguns reparos desses em equipamentos diferentes e prefiro retirar o acabamento original do cabo (abrindo ele ao meio com o estilete) e recolocar no cabo após o reparo, fechando-o com super-cola. Assim a fonte fica com aparência de original.
johnokdk2 years ago
usefull. I use a hammer to crack those plastic welds all around the seam. Just give it a good tapping all way around it will open.!
Last time I did that. I bricked my laptop coz I got the polarity wrong. Oh actually I didn't, a professional fixed it for me and then after my laptop was in fumes. I noticed he had fixed them wrong.
Say: hello new laptop!
3366carlos2 years ago
very cool.
hildymarie2 years ago
thank you, thank you, thank you. I', thinking I can repair my printer power cord much the same way. Hopefully I didnt throw it away lol
31mimo2 years ago
I use na hammer and 2 pieces of wood or cardboard . I hammer round the joints . no need to use a screw driver. and no external or internal damages. The final work puting back together with contact glue. NEW
E1Mike2 years ago
I usually check the voltage before doing a strain relief, in case the voltage isn't ok (never happened, maybe i am paranoid), but if you rescue the strain by striping the cable you can do it at the end. excelent instructable!
szarei2 years ago
It make me think, repair and reuse instead of buying new! Very environmentally friendly and economic !
Well done!
Thank you for this! I actually have the exact power cord that needs this repair! Great job, very very helpful!