Repairing damaged USB cables is often accomplished through the replacement of the cable. It is often more advisable to purchase a new cable, as repairing any damage can be more expensive than a new cable. If you decide to repair your cable, you will need patience, a new connector end, and in most cases, a soldering gun. The process can be lengthy, but if you desire to keep your existing USB cable, you can make repairs.
Disconnect the damaged end of the USB cable. Some cables have USB ends that plug on to the ends of the USB cord and can be easily pulled off. Most damaged USB cable ends will need to be cut off with a wire cutter.
Purchase a new USB connector end. These can be purchased from electronic and computer retailers. Most connector ends come with a connector that has a 1- to 2-inch length of USB cable attached to it. If your USB end plugs into your existing cable, you will need to purchase that type of USB end, which is also easily found at electronic and computer retailers.
Plug in your connector if your USB accepts these types of ends. Once plugged in, test the cord to make sure it is working. If your USB cable does not accept plug-in connectors, cut a small opening in the hard plastic of the cable side of your connector to allow about 1cm of the wires to be visible. There will be a red and black set of wires. You may need to use a wire stripper to remove any remaining plastic so that the metal of the wires are visible
Turn on your soldering gun and allow it to heat up. Press the soldering gun to the exposed metal wires of your old cable and allow the head to lightly melt each wire's tip. Do the same to the wires in your new connector.
Quickly press both ends together. The red wires from the old cable should be attached to the red wires from the new connector end and the same goes for the black set of wires.They will almost instantly be bonded as soldering cools very quickly. It does not matter in which order you connect the wires as long as you connect red wires to red wires and black wires to black wires.
Trim off any excess hard plastic with a hobby razor knife and cover the mended area with black electrical tape.