Cable fault tester is one of the common equipment to detect cable fault. It has stable performance, can quickly and accurately find out the fault point, and the maintenance personnel can quickly carry out maintenance work, which greatly provides work efficiency. The purchase of cable fault tester is also a problem valued by many friends. Next, we will focus on the precautions for purchase. Another situation of the power supply analysis of the damage of the cable fault tester in recent years, 80% of which is due to the poor wiring or wrong wiring during high-voltage impulse flash, resulting in the damage of the instrument. If the battery is used for power supply, even if the high-voltage is connected in series, it will not form a loop to the earth and can only cause the common mode effect, so as to completely avoid the occurrence of machine damage accidents. Problems of collector and notebook computer: the test scheme of collector notebook is a design scheme proposed by the company in 1996 and put into practice. In 1997, the cable fault test and management system was launched. Through several years of market use, it seems that it does not adapt to China's national conditions. At that time, the principle considered in the design was to give users a good tool and strong data processing ability. But for the following reasons. At present, it has been discontinued. Reasons why notebook collector is not suitable for on-site cable fault test: 1. The on-site environment is not suitable for the use of notebook computers. Generally speaking, notebook computers are relatively delicate and suitable for office or business travel. However, most of the cable fault tests are in substations or outdoors, with large dust, large interference and complex environment, which will greatly shorten the service life of notebook computers. And the sampling waveform is not good. 2. Generally, the switching power supply of notebook computer can only be used when the impact of power grid is small. When the high-voltage impulse flash of cable fault is carried out, the power grid fluctuates greatly, which is very easy to cause damage to the power supply of notebook computer. Therefore, when testing the high-voltage impulse flash of notebook computer, it is emphasized to disconnect the charging power supply and test with the internal battery. 3. In the cable fault test, the high voltage string into the tester is a common problem due to the wiring problem. The impact resistance of the notebook computer is very weak. High voltage enters the notebook computer through the test line collector, which will eventually lead to the damage of the notebook computer interface. Such lessons have been encountered in several cases in our customers. Although current sampling can improve the safety of equipment at present, current sampling is chaotic for short-range fault waveform and difficult to identify, so it is often misjudged when testing short-range fault. 4. Computer viruses will affect the normal use of the equipment. Such problems seem to have nothing to do with our equipment, but users will inevitably make the computer impacted by various computer viruses when using the computer. When there is a problem with the cable, there will be various problems when taking it out for use, and it will not work normally. This results in delayed power supply. At present, the cable fault tester with advanced performance should be equipped with an interface for communication with the computer. Select the cable fault tester with computer interface and test with the cable fault tester on site. After the test, the test waveform needs to be saved and uploaded to the laptop or other computers for archiving, analysis, production of test reports, etc. It should be the best procurement scheme.