In today’s digital era, a reliable network connection is essential. Whether you're setting up a new internet line, troubleshooting slow speeds, or managing a home or office network, ensuring your LAN (Local Area Network) cables are functioning properly is critical. This is where a LAN cable tester comes in handy. For beginners, using such a device might seem intimidating, but with a little guidance, it’s actually quite simple.
In this article, we’ll walk you through everything you need to know about using a LAN cable tester, including its components, how it works, and a step-by-step guide to using it properly.
What Is a LAN Cable Tester?
A LAN cable tester is a diagnostic tool used to test the integrity and connectivity of Ethernet cables (usually RJ45) and sometimes telephone cables (RJ11). It checks for common wiring problems like:
- Open circuits
- Short circuits
- Miswiring
- Crossed wires
- Continuity faults
Some advanced models also measure cable length, identify PoE (Power over Ethernet), and even trace cable paths using a tone generator.
Who Should Use a LAN Cable Tester?
You don’t have to be a networking expert. These testers are helpful for:
- IT professionals and network technicians
- Electricians
- Home users installing routers or Ethernet networks
- Gamers and streamers troubleshooting connectivity
Types of LAN Cable Testers
There are generally three types of LAN cable testers:
- Basic Cable Continuity Testers – These test if each wire in the cable is connected properly.
- Advanced Network Testers – These test speed capabilities, cable length, and signal strength.
- Wire Tracker with Tone Generator – These help you trace cables hidden in walls or bundles.
For beginners, a basic continuity tester is usually sufficient.
Components of a Basic LAN Cable Tester
Most LAN cable testers consist of two parts:
- Main Unit (Master): This is where the cable is connected on one end.
- Remote Unit (Slave): This connects to the other end of the cable being tested.
They usually have LED indicators labeled 1 to 8 (for each wire in a standard Ethernet cable) and sometimes a G for ground.
How to Use a LAN Cable Tester: Step-by-Step Guide
Here’s how to use a standard LAN cable tester to test an Ethernet cable (RJ45):
FEDUS LAN Cable Tester
Step 1: Power on the Tester
Insert a 9V battery (or AA batteries if required) and turn on the power switch. Most testers have an ON/OFF button or switch.
Tip: Always check if the tester is working by seeing if the lights or display activates.
Step 2: Connect Both Ends of the Cable
- Plug one end of the Ethernet cable into the Main Unit (Master).
- Plug the other end into the Remote Unit (Slave).
If you're testing a cable already installed in the wall or between two rooms, you may need to detach one end and bring it close to the tester or use the remote module.
Step 3: Initiate the Test
Turn the tester to the test mode or simply let it run (some models test automatically when a cable is inserted).
The lights (or digital display) will start scanning from 1 through 8 (and sometimes G). The pattern of lights tells you the status:
- Correct Wiring: LEDs on both ends light up in order (1-8).
- Open Wire: One or more LEDs fail to light.
- Short Circuit: Two or more LEDs light together (indicating wires are touching).
- Crossed or Miswired: LEDs light out of order.
Example: If wire 3 is connected to pin 6, the LED for 3 on the main unit and 6 on the remote unit will light together.
Step 4: Interpret the Results
Here’s what the different outcomes mean:
LED Pattern Meaning
1-2-3-4-5-6-7-8 Correct wiring
Missing LEDO pen circuit
Two LEDs light at once Short circuit
Out-of-sequence LEDs Crossed wires or miswiring
No lights Cable not connected or dead battery
Step 5: Repeat with Other Cables
Test each cable individually. If you're testing multiple cables, label them to keep track of which ones pass and which ones fail.
Step 6: Store Safely
Turn off the tester and remove the battery if you don’t plan to use it often. Store it in a cool, dry place.
Advanced Testing (Optional)
If you have a tester with a tone generator, you can also trace cables hidden in walls or switchboards:
- Connect the tone generator to one end of the cable.
- Use the receiver/probe to locate the cable by following the tone sound.
This is especially useful in complex installations or when multiple cables are bundled together.
Common Mistakes to Avoid
- Not inserting the cable fully: Always ensure the connectors click into place.
- Testing damaged connectors: Bent or corroded pins can affect readings.
- Ignoring power: A low battery can cause false negatives or no reading.
- Testing live wires: LAN testers are not designed to test cables carrying power. Disconnect all power before testing.
Recommended LAN Testers for Beginners
- FEDUS LAN Tester with Wire Tracker – Affordable, includes tone function, works with RJ11/RJ45.
- Zoostliss Cable Tester – Simple, LED indicator-based.
- Seesii RJ45 Cable Tester – Lightweight, reliable for everyday use.
These models are readily available on Amazon and other electronics marketplaces in India.
FEDUS RJ45 and RJ11 Network LAN Cable Tester
Conclusion
A LAN cable tester is an essential tool for anyone dealing with wired networks. From checking for connectivity issues to verifying a new installation, it provides clarity and saves time. While the idea of testing network cables might seem technical, the actual process is simple and straightforward.
With this step-by-step guide, even a beginner can confidently test LAN cables and ensure a stable, reliable internet connection at home or the office.