How to Tell if Ethernet Cable is Bad

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Although the transition from wired to wireless connectivity has been a sudden one, there are still plenty of people who make use of a wired connection for all of their networking needs. While both solutions have their fair share of pros and cons, plenty of people seem to hold wireless connectivity in higher esteem for one reason – it’s wireless.

The lack of cables and cords makes setting up and using a wireless connection far simpler, even if the quality of the Internet connection itself is lackluster. People just don’t want to have to fiddle with wires all day long to get their network up and running.

For those of you who still make use of a wired connection, we don’t need to tell you how excruciating it can be at times trying to untangle the many cords and cables that make up your home network. One of the most important of these is, of course, your Ethernet cable, which needs to be in tip-top shape to do its job and do it well. When an Ethernet cable isn’t working, it opens you up to a sordid array of other issues.

To avoid this, you need to know how to identify when an Ethernet cable is bad – luckily, we’re here to help. Here’s how to tell if Ethernet cable is bad.

Loss of Connectivity

This is by far the most apparent indicator that something may be up with your Ethernet cable, and in all likelihood, it is probably what led you to this article in the first place.

When you lose your connection to the Internet on a wired network, it could mean that at least one end of your Ethernet cable has not been properly attached to its respective adapter. To check this, all you need to do is take a look at both adapters and check their LED lights.

If both are flashing, it means that the Ethernet cable is properly connected to both ends, eliminating this as a possible cause of your network issues. Fiddle around with the Ethernet cable’s physical connection to the adapters, holding it at different angles to see if the fault is due to some fickle wiring within the cable rather than the adapters.

To properly rule out the adapters as the cause of the issue, try using another Ethernet cable that works to test if your connectivity issues still arise. If you find that this other Ethernet cable solves the problem, you can stop reading now. Otherwise, you may need to call your ISP or a professional to solve the problem.

Lag Issues

This is another common issue that many people using a wired connection may face, though it usually isn’t too much of a problem for people who don’t game or stream frequently.

Still, dealing with lag is annoying. While the fault may simply be with your ISP, we first need to test your Ethernet cable before you contact them.

To do this, all you need to do is check on your Internet speed. Your ISP will have specified the Internet speed (measured in Mbps) when you signed up – if this speed doesn’t match the one you read, there are two possible causes.

The first one is simple, and it’s one we mentioned at the start of this section. Your ISP could also be suffering from connectivity issues.

The second one involves your Ethernet cable being faulty. You’ll notice whether or not this is the case when you take a look at the numbers between which your Internet speed fluctuates when in use. If, for example, your package specifies a network speed of 1 Gbps and yours only fluctuates between 200 and 300 Mbps, then the problem lies with your cable.

In this case, the only real solution is to replace the cable itself. Remember, though, that a little bit of a discrepancy between the specified speed you’re meant to receive and the one you actually get is to be expected – it should only be a problem if it dips significantly low.

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Occasional Dips or Loss of Connectivity

Sometimes, your Internet connection seems perfectly fine, and then, all of a sudden, it’s lost. This may be due to some issues with your ISP. However, more often than not, it’s a problem with the wiring within your Ethernet cable, which can become bent and twisted and only work intermittently.

You could simply replace the cable and move on, but if the damage to the wiring isn’t too severe, you may be able to repair it yourself.

To do this, determine the bend in the cable that has caused the wires to become damaged. Cut the rubber casing off at this area, and with pliers or something similar, reconnect the different wires according to the colors that denote them. (Red goes with red, blue with blue, etc.)

Seal it up with some insulation tape and test your connection once more, and if the problem persists, it’s time to get a new Ethernet cable.


Those are all the easiest ways to identify a faulty Ethernet cable. Sometimes, it’s the fault of your ISP – other times, the easiest and quickest solution is to simply replace the cable itself.

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  1. Pingback: How To Run Ethernet Cable Through Ceiling - Electronic Ink Blog

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