How to Make Ethernet Cable Checker





Introduction: How to Make Ethernet Cable Checker

About: I'm student of Software Engineering.

My ADSL Modem is far away from my home so I use Ethernet cable to bring internet to my home...But sometimes internet is disconnected. I noticed that is is the fault of cable. So I made this small but very helpful gadget...Concept behind the project is very simple.... In Ethernet, connection is established through only 4 wires out of 8. (I will discuss Ethernet cable jack pinout in next steps)...So I checked only 4 wires...If these are OK cable is suitable for Broadband Internet. But If some LEDs are not ON or all of them are OFF then Cable is cracked/broken...

Step 1: Part List

1). RJ-45 Socket x2

2). 1.5 Volt AA Battery x2

3). AA Battery Holder x1

4). Matrix Board x1

5). 3 volt LED x3

6). 3 volt small LED for Power Indication x1

You should also have wires and soldering experience and proper soldering tools (Soldering Wire, soldering iron, soldering rosin, etc.).

Step 2: The Power Unit - One End

This is the power source for LEDs. I used RJ-45 Socket. And I used 2 AA batteries (1.5v*2 = 3 volts) to power 3 LEDs on the Second End on other side of wire.

Step 3: LED Indicator Unit - Other End

On the other side of wire I made a small unit containing 3 LEDs to check the 4 wires of Ethernet cable. 3 LEDs are for 4 pins (3 pins are +ive, one for each LED While 1 pin in for -ive/ground, common for each LED).

Solder the 1,2,3 and 6 number pins of RJ-45 Socket to +ive and -ive terminals of LEDs respectively. That's All...

Step 4: Ethernet Cable Pinout

Step 5: Circuit Diagram

Step 6: Checking the Cable

I have checked my 200 feet cable with my cable checker....

To check the long distance cable you have to do only a small effort, plug one end of cable on Power Unit and other end of cable on LED Indicating Unit.
If all 3 LEDs are ON, Your cable is Okay.

If any of these LED is OFF, Cable is broken or Connectors on the ends of cable are not connected to cables properly.

Hence you can diagnose any Ethernet cable on your own with the help of this small but very useful tool...

Please vote for this...Thanks..!!!



    • Clocks Contest

      Clocks Contest
    • Creative Misuse Contest

      Creative Misuse Contest
    • Oil Contest

      Oil Contest

    46 Discussions

    very well... (y) Its might me helpful. I am also a student of Computer Science. I will make and test this one and I thought it will work as you described.

    Thats Perfect small but very useful tool.

    Nice project....Do you tested this properly for Ethernet connection of every type connection ?

    1 reply

    It test it in my connection as I described above in description. And I sure this will work perfect for small scale connection network. work it can't be used in the connection having POV (Power Over Ethernet) so Do'nt use it there.

    Bohat aala jnaab.... Great Idea... (y) :-D

    perfect work (y)

    هو أداة جيدة للغاية. أنا أحب ذلك لجعل. عمل جميل وإخوانه

    1 reply

    Nice job Tehseen. I will use this to check the connections in my Ethernet networking while making Films.

    small but useful (y) ....Yeah nice thing

    Okay its funtastic small but useful tool. But can it be used for gegabite connection, etc. ?

    1 reply

    Thanks. No It is only for megabites connection. because it uses only 4 wires out of 8.... But you can also make 8 wire checker similarly.

    That's perfect Tehseen. I will sure make this. because I often need this type of gadgets. (y)

    Nice work :) and Yes a Box would be great, and i was thinking.. even something as simple as a push button switch or toggle switch. between the power and the first for each line and you'll break the circuit so you can see if a wire is crossed ..?

    1 reply

    Great instructable. but 1 WORD OF WARNING. this will only give you verification of continuity on all wires. It won't verify you have each RJ45 connector pin to the right color wire on each end. You still need to make sure you have all the right colors connected to the same pins on the RJ45 connector at both ends.

    if some of your wires were connected too different pins on the RJ45 connector at one end vs the other, you'd still get a solid light.

    1 reply