How does a LAN Cable Tester work?

Some sites teaches you how to make RJ - 45 network cables. But as I browse over the net, I only found few sites that teaches you how to test the cables that you've made. One means of it is by using a LAN Cable Tester.

As shown in the figure above, this is a cheap LAN Cable Tester that I bought at less than 200 pesos(approximately 4 USD). However, it is well enough to get the job done. And now, how do we use it? Well, here are the steps:

Step 1: Get your newly - made RJ - 45 network cable and connect both ends of the cable in both RJ - 45 ports of the tester as shown in the figure below.

Step 2: You should see that the LED indicators at the same pin number lights up at the same time, or according to the correct sequence according to the cable you've made. Otherwise, your cable does not work.

Here are the following LED indication sequence that you should see when using your LAN Cable Tester:

If your newly - made cable does not work, the following reasons may have occured:

a.) Either ends of the cable, are not well crimpped yet. Try to crimp it more.

b.) Wrong color coding scheme when making the cable. Double - check the color coding depending on the variation.

Hope this post shed some light (again) for those PC techies out there.