These steps can be used for most all models of headphones. For very inexpensive headphones the wires will be too fine (small) to work with
For this Instructable I'm fixing the plug on Sony headphones.
What you'll need:
Wash your hands. Oil on your skin is the #1 reason wires handled do not solder successfully.
You'll need the ability to solder.
A soldering iron capable of over 700 degrees Farenheit is helpful, but a normal one works with extra care.
Wire Strippers, wire cutters, long nose pliers, electrical tape, scissors to cut the tape (not pictured) or use the wire cutters. (OH -A pair of wire strippers can replace all three cutting - stripping-plier tools)
If you have heat shrink ability be sure to remember to put the heat shrink tubing (about 6" of 1/4" or 3/8" over your headset cord at first chance. This way it will be there when you need it at the end.
Step 1: 1. Select the New Jack for Your Headphones
These connectors come as just one plug with wires attached and soldered ("tinned") on the ends for a bit MORE money than getting one of these. A two ended 3.5 mm plug cable is a couple dollars. AND you can now repair TWO headsets.
Step 2: 2. Prepare the Plug End of the Cable
Step 3: 3. Get New Cable Plug Ready for Solder
Neaten it up. Twist the ground wire. Strip the RED ( Right channel ) and the OTHER ( in this case WHITE left channel conductors. Take about 3/4" off the end.
TIN the ENDS. That means melt a tiny bit of solder into the bare end of each of the three wires. THIS IS A KEY TO YOUR LATER SUCCESS.
Step 4: 4. Prepare Headphone Cable
Yes, you paid 30 or 40, or 50 dollars for these things and even though they don't work it always hurts to make something ugly in order to make it beautiful and work again. It will be OK. Let's take it slow.
Now, the rest is easy.
ANOTHER KEY TO YOUR SUCCESS
Strip the insulation off each side of the "ZIP CORD" the side-by-side flat cable these come with.
MAKE IT UNEVEN. MAKE ONE SIDE STRIPED AN INCHE OR SO MORE THAN THE OTHER.
This will make your repair stronger and resist ever breaking again.
Step 5: 5. Prepare for Strong Connections
The next few moves outline something specific that will make this repair like one from a professional shop, not one you let your kid brother do.
Bend one ground wire from the headset cable back toward the headset. Leave a small loop, so don't crease it hard, but do what they always tell you not to do: Bend it backward.
Then, do the same with the other ground lead from the other half of the cable and twist the two bare wires together. You did wash your hands first, right?
Make sure the new wire from the plug overlaps the cable from the headset . It should stop between the two offset sides of the headphone cable.
Solder the ground wires together
Step 6: 6. Begin to Join Cable and New Plug
Twist the new cable ground together with the combined ground wires on the headset side of the cable.
SECRET TO YOUR SUCCESS - overlap the non-stripped part of the plug cable with the headset cable. This will make it look like it is picking up where the shorter side of the headset cable leaves off.
Twist together the red to red and green to what is left. Often green, sometimes white. White in these photos.
Step 7: 7. Bring Together Right and Left Channel Wires
Bring together and twist the Right Channel (red wires) and the Left Channel (green to green or green and white.
Twist and keep the resulting cable flat and straight.
Prepare to solder Right and Left Channels
Step 8: 8. Solder Plug to Headphone Wires
Why slowly? Because we have to bake through the SONY plastic coated headset wires. We scraped them a little in the last step, Now, we solder and wait. You'll see solder smoke and some new plastic smoke. Just a little bit. No lab rats got dazzled in this experiment.
Solder Right and Left Channel.
OK. STOP !
Don't tape or cover your joints because this is where the new folks get caught. In case you did not heat the solder joint quite enough you will not have contact at that connection. So, leave the connection bare until testing is over.
You guessed it. TESTING is next.
Step 9: 9. Testing
I used a Mac and the edit program Final Cut Pro and made a timeline with alternating left only and right only sounds.
Be sure to put the headphones on so the left is on your left ear and the right is on the right ear.
(Hey, don't look at me like that. I have a friend who put them on backward and ripped the whole connection apart to put it back right - then found out he didn't have to because the headset was on backward. Boy did I - er - he feel stupid. )
Is Left where it belongs and Right where they belong ? Congratulations !
If one or both do not work, Congratulations ! Your're Normal.
You've been slowed by the funny insulation on these wires. Simply re heat the solder joints. Maybe scrape a bit more plastic off the surface - being careful to not tear or shorten the wire.
Step 10: 10. Make Cable Strong, Beautiful, and Long Lasting
In picture 29 the headset is to the left, the new plug is to the right. GROUND is pointed to the headset and the well insulated RIGHT AND LEFT channel wires are pointed to the right - toward the new plug. If the dog ever gets ahold of this cable the worst that will happen is that your left and right will short and you'll have mono headphones, not dead ones. Cool, huh?
Make sure the cables overlap slightly like we talked about.
Use small pieces of tape to put the cable together.
Tape or use heat shrink on the solder connections.
If you forgot to put shrink wrap on your headphone cable before you started, like I did,
do it with two courses of tape. One from the headset to the jack, and another going the reverse direction.
Test it again, just to be proud. It will work just fine.
Two views of cable finishing. Heat shrink is not shiny, Electrical tape is shiny.