There are many engineers that are providing the services for cable locating through special equipment and they also get paid higher because of the difficulty of this process. These engineers have special underground cable fault locator which will help them to locate the exact location without any glitch because knowing about the exact location is first step in correcting the fault. If you do not know about the location then they will not be able to correct it. There is a detailed process which needs to be done in proper steps. If you want to know about these steps then you have to see below:
First step is to make the cable safe for operations. To do this it is necessary to isolate both ends of the cable so that there will be no electricity and the person will be safe from the electric shock. This isolation is better to do at both the ends to avoid even a single voltage but only one end can also be isolated and earthed for the safety measure.
Second step is to identify the cable and this step should be done with great precision so that you will not damage the right cable. You can also use the cable and pipe locators in this process so that you will know about any water line nearby and can avoid damaging it unknowingly. If you are not clear about the damaged cable then you should not do anything to the cable in front of you because it may prove deadly to you and also interrupt the electric supply.
Third step is to know about the route of your selected cable because these are not laid in an exact straight path, instead there will be twists and turns in the rout so it is important to know where the cable exactly goes and only then you will be able to find the default.
Fourth step is to identify the fault in order to make it right. For this purpose certain locators are used and there are two types of faults, one is of low resistance which is below 100 Ohms and other one is of high frequency which is more than 100 Ohms. They both need to be detected with different detectors so you should also know about the frequency and resistance before you make it right.