If you see these signs, replace your modem immediately.

Electronic devices run constantly and the hotter the device is the faster it tends to degrade. Modems fall into this category.

Could the modem be faulty?

Most people leave their modems on 24 hours a day, even while they sleep. The modem is constantly communicating with your ISP and handling traffic between any devices in your home that can automatically connect to the Internet. This can include mobile devices, smart home devices, and more.

Because of this, the modem is always hot. That heat quickly degrades the electronic components inside the modem. Most modems show signs of failure before they stop working.

Before you do any troubleshooting, make sure to reset your router to its factory default settings. Doing this will fix most modem issues. If not, the troubleshooting tips below will help you determine if you have a working modem.

How do I know if my modem is faulty?

If your Internet connection is dropping frequently or your modem is rebooting on its own, you may have a faulty modem. The following steps will help you determine if your modem is faulty and whether you should replace it before it completely dies.

1. Your Internet connection is slowing down significantly.

This is often one of the first signs that your modem is having problems. First, call your service provider and confirm what your current download and upload speeds are for your account. Next, connect an Ethernet cable from your computer to a numbered network port on your modem. Turn off WiFi on your computer to make sure you're connecting to the Internet via Ethernet. Open Google and type "internet speed test" and select Run Speed ​​Test. If your download and upload speeds are much slower than what you're getting from your service provider, this could indicate a faulty modem.

2. Modem is overheating

Overheating is a common sign that your modem is no longer cooling properly because faulty electrical components tend to heat up more. To test if this is happening, leave your modem on for at least a day. Then, place your bare hand on the side of the modem. If it feels too hot, your modem may be faulty and it may be time to replace it.

Note: Not having enough free space around the modem can also lead to overheating, so before performing this test, make sure you let the modem run for a while with plenty of free space around it so the device can cool itself.

3. Modem reports many errors

Every modem has administrative troubleshooting tools. These usually include an error log. Another sign of serious modem problems is frequent critical errors in the error log. Access this log by logging into your modem as an administrator and navigating to the advanced administration section. Look for the Event Log or Error Log in the navigation menu. If you see a long list of critical errors every day, it is a sign that your modem's software or hardware is failing.

4. Modem light shows multiple error signals

Check the modem lights. Each modem light has an important function. These lights tell you whether the modem is connected to your ISP, transmitting as a WiFi network (if it's acting as a router), and sending data. If the top light labeled "Cable," "Cable Link," or "WAN" ("DSL" or "Phone" for DSL modems) isn't lit but your ISP tells you the connection seems fine, your modem may be faulty. If the data transmission light (usually labeled "Activity," "Data," or "PC Link") doesn't flash even when you're using the Internet, this could indicate that your modem is starting to fail.

5. Modem resets itself

A modem that frequently resets itself is a common sign that it is not working properly. Some things to check before replacing the modem include a loose power connection or faulty power adapter, a bad cable connection to the wall (coaxial cable), overheating (as mentioned above), or an overworked modem.

6. Modem not responding

If your modem is unresponsive and all the lights are on, this is a sign that the modem is "dead". Symptoms of an unresponsive modem include:

1. No Internet access when you connect via WiFi or with Ethernet cable 
2. Unable to connect to WiFi (if it is dual modem/router) 
3. Unable to connect to modem using default gateway IP address

Note: Always try unplugging the modem, waiting the full 60 seconds, and then plugging the modem back in. If the unresponsiveness persists after rebooting, it may be time to replace the modem.

Kareem Winters

Update 16 January 2025