Our cats enjoy chewing on headphone cables, and of course we never catch them in the act. So in this case, a pair of Apple headphones were the victim. This model also has the inline mic and remote, which adds a couple more wires. Before starting, make sure to have some small heat-shrink tubing, I purchased Radio Shack heat-shrink as a kit that has some very small 1/16″ tubing and with multiple colors. The 1/8″ white will be important when finishing the project.
Other items that will be needed: Very sharp diagonal or side cutters, soldering iron with a fine tip, extra hands soldering aid, new razor blade and a heat gun and lighter.
To begin with, the portion of damaged cable must be removed. Use the cutters to remove about 1/4″ on either side of the ruined section. Once that is done, strip back about an inch on both pieces. Take the full length of white 1/8″ shrink tubing and slide it over either side of the head phone cable. Failure to do this now will make for a unhappy times later!
Identify the wires and prepare for soldering. Normally the wires would be stripped of insulation, however these wires are so small that it is not possible to use traditional stripping methods. Simply use the soldering iron, with a small amount of solder, to melt/burn the insulation and tin the wire at the same time. Using a soldering aid, I worked with one set at a time, just matching the colors. For example, I started with the copper colored wires (there are two sets, grounds so just choose any two). Before connecting the wires, put a small piece of 1/16″ shrink tubing on one side, pushing it as far from the connection as possible. When soldering, make quick work of it so the tubing does not start to shrink. I used a lighter to melt the small heat shrink, I was afraid the heat gun would be too much for the small wires. Just exercise caution, very little heat is needed for this step.
Repeat the process for all the wires. When done, carefully slide the over larger heat-shrink, centering it over the repared section. Using the heat-gun (or lighter), gingerly heat the tubing util there is a tight fit. The excess length will add support to the repair.
It’s obvious that a repair has been done, but not too obvious. Several patches like this have been performed over the years on various cords, and each one is still working great.