If you find a problem in the wire, then it must immediately be removed, as this can lead to deplorable consequences.
In order for the wire to be repaired, it is enough to use such improvised materials as a knife, a soldering iron, isolet, rosin, solder, heat -shaped tubes. The difficulty of repairing the wire you need will depend on where it will be intended.
If we talk about how to find a gap place, we can say that it is fast enough and easy to do it as soon as you find a damaged area, you will have to free two centimeters of the wire from each side. You can do this with ordinary nippers or a paper knife. As soon as you get the wires, you will need to remove the oxide from the wires. This will help you get to shiny wires. Then you will have to disconnect these wires and try to connect by a new one, but at the same time use the island to prevent the appearance of a fire.
If you saw that the wires have the necessary integrity, then it will be possible to call a specialist who will help to cope with your problem, as modern technologies and means will use.