How can I test the quality of my network cable?

How can I test the quality of my network cable?

1. Due to the normal Internet access, the router still cannot access the Internet after restarting, it is necessary to judge whether it is a problem of poor network cable connection.

2. There are a total of 8 network cables, of which lines 1, 2, 3, and 6 are mainly responsible for data transmission. The corresponding network cable colors are white orange, orange, white green, and green.

3. First, use a line tester to check whether the 1, 2, 3, and 6 lines of the network cable are well connected. If they are connected, there will be a green light on the line tester.

4. If one or two green lights of lines 1, 2, 3, and 6 of the line tester are not on, do not directly judge the network cable.

5. If the 1 or 3 line is not bright, you can use the 7 line to exchange, and then redo the crystal head (the two ends of the network cable must be exchanged again), and then use a line tester to measure to see if it is changed to the 7 position. 1 or 3 cables will not light up green.

6. If the 2 or 6 line is not on, change the 8 line, then redo the crystal head, and then use the line tester to see if the green light of the line changed to the 8 position is on.

7. After the exchange, it may be found that the 1, 3 or 2, 6 network cables that were not bright before are bright, and it can be judged that there is no disconnection in the middle of the network cable. By this method of replacing the network cable, the two situations of poor network cable contact and failure of crystal head production can be excluded. If the green light is on after the network cable tester tests the network cable, it means that the network cable can be connected normally. , you can avoid spending a lot of time re-unplugging the network cable.

When there is a problem with the line in the network, how can we analyze and eliminate it?

Problem 1: The RJ45 connector of the network cable is loose, resulting in poor contact.

This kind of problem is the most common problem. Due to frequent plugging and unplugging of the network cable, the quality of the network cable is poor, and the production process of the crystal head is problematic. Therefore, when the normal network cable is used for a long time, there will be poor contact. affect the Internet.

Fault phenomenon:

In the case of excluding the disconnection of the network cable itself, when using the line measuring instrument to measure the line, the performance is as follows: some indicators do not light up

solution:

Rework the problematic crystal heads.

Problem 2: The metal antenna on the RJ45 connector is oxidized and dusted, resulting in poor contact.

This type of problem is mainly prone to occur in a humid environment, and the metal antenna on the crystal head is oxidized by the air or covered by dust, resulting in poor contact. Of course, this also has a certain relationship with the quality of the crystal head itself.

Fault phenomenon:

Check with the naked eye to see if the metal tentacles on the crystal head have turned black or have a lot of dust; further test with the help of an online measuring instrument.

solution:

Rework the problematic crystal heads.

Problem 3: The RJ45 line sequence is wrong.

There are certain standards and specifications for the production of crystal heads, and it is best to make them in strict accordance with the standards and specifications.

The standards are as follows:

568A: White Green | Green | White Orange | Blue | White Blue | Orange | White Brown | Brown

568B: White Orange | Orange | White Green | Blue | White Blue | Green | White Brown | Brown

Usually, both ends of the network cable are made according to the 568B standard, which is commonly known as a straight-through network cable;

Crossover line: one end is 568A, the other end is 568B, which are rarely used now.

Fault phenomenon:

When testing through the line tester, the light sequences of the indicators at both ends of the line tester cross (only for straight-through lines)

solution:

Rework the problematic crystal heads.

Problem 4: The metal antenna of the RJ45 connector is shorted.

Such problems are relatively rare and difficult to find, and often appear on some inferior crystal heads.

Fault phenomenon:

When using the line measuring instrument to measure the line, the performance is as follows: some indicator lights on the line measuring instrument flash at the same time.

solution:

Rework the problematic crystal heads.

Question 5: Some of the cores in the network cable are defective.

How to troubleshoot:

Through the fault diagnosis instrument of the line tester, under the test line, if there are several core wires on, the disconnection may occur.

Solution:

100M 100 cores, as long as the network cable has 4 through lines; for the network cable that has just been replayed.

Here is a very professional tool for checking network cables：