When testing twisted pair cables, possible problems include: near-end crosstalk fails, attenuation fails, wiring diagram fails, and length fails. The following are described separately:
1. The reasons why near-end crosstalk fail may be:
1) There is a problem with the nearest connection point;
2) The remote connection point is short-circuited;
3) Serial pairs;
4) External noise;
5) There is any performance problem with the link cable and connector or it is not the same type of product;
6) There is a problem with the termination quality of the cable.
2. The reasons for failure to pass attenuation may be:
1) Too long;
2) The temperature is too high;
3) There is a problem with the connection point;
4) There is any performance problem with the link cable and connector or it is not the same type of product;
5) There is a problem with the termination quality of the cable.
3. The reasons why the wiring diagram fails may be:
1) The joints at both ends have broken circuits, short circuits, crossovers, and cracks and open circuits;
2) Jumping error (Some networks require the sending and receiving end to jump. When building a test link for these networks, the test wiring diagram will cross due to the jumping of the device lines).
4. The reasons for failure to pass the length may be:
1) The NVP setting is incorrect, and NVP can be determined and recalibrated by known good lines;
2) The actual length is too long;
3) Open or short circuit;
4) The total length of the equipment connection and jumper is too long.
5. Tester problem
1) The tester does not start, the battery can be replaced or charged;
2) The tester cannot work or is unable to be calibrated remotely. Make sure both testers can be started and have sufficient batteries or replace the test cable;
3) If the tester is set to the incorrect cable type, the parameters, categories, impedance and nominal transmission speed of the tester should be reset;
4) The tester is set to an incorrect link structure and reset to the basic link or via link as required;
5) The tester cannot store automatic test results, confirm that the selected test results name is unique, or check the capacity of available memory;
6) The tester cannot print stored automatic test results. The interface parameters of the printer and tester should be determined, and the same should be set, or confirm that the test results have been selected as printout.