(Solved) Modem lights blinking really fast – How to fix

Like a router, the modem comes with various colors that have different meanings. As you use the modem, you should understand what each light means. Sometimes, the lights on your modem may start blinking real fast.

When the DSL light on your modem keeps on blinking fast for long, it shows that your modem has a problem. This indicates that the modem is struggling to pick up the signal correctly. The blinking lights can make it hard for you to access the internet as usual. You should learn how to fix this problem by trying things such as power cycling the modem, confirming that the connection is secure, changing the IP settings, or plugging the phone cable directly to the wall outlet. Here is more!

How to fix a modem with fast blinking lights

Power cycle the modem

Power cycle your modem

You should start by power cycling the modem. Doing this can fix the DSL connection problems that may be making your modem to blink really fast. Start by shutting down all the devices that you have connected to your router and modem. Some of the devices may include the computer, smart thermostat, or video doorbell. For you to shut down some devices, you should utilize the operating system menu rather than the power button.

If you have been using a router, you need to unplug it from the power source. Give the modem at least a minute, then plug it back to the power source. Doing this can help boost the performance of the internet connection. After the power cycle, check whether the modem lights are still blinking fast. If they are, you should try alternative options. You could, for instance, try rebooting your computer. Sometimes, doing this can help solve DSL connection problems. This a crucial step to take, especially if your PC has been working fine before.

Check the connection

Proceed with checking if your modem is connected properly. Inspecting the connection can help you identify a loosely connected or damaged cable. If the Ethernet cable that you have connected to your modem is damaged, you need to replace it. Apart from the modem, you should ensure that devices such as your fax machine, alarm system, or satellite receivers have DSL line filters. Such filters can block any interference with the DSL signal. Make sure that the modem is the only unfiltered device. You should also ensure that you use the right power adapter for the modem.

Plug the phone cable to the wall outlet

You should also ensure that the phone cable that comes from the modem plugs into your wall outlet directly. Bypass splitters since they are known to sometimes cause interference with the DSL signal. You can even remove the phone cable then plug it back into the wall jack and modem. When you have plugged in the cable securely, you should not experience blinking lights on the modem. Watch out for a click sound when you push the cable into place.

You should also try connecting your modem to a different phone jack in case the one you are using is faulty. Since internal wiring issues can sometimes cause this problem, moving the modem to a different phone jack can help you solve the issue.

Check the IP settings

port forwarding process

Have you made changes to your home network settings of late? If yes, this could sometimes be the cause of the fast blinking lights on your modem. If, for instance, you have added a router to the network or recently installed your DSL, you should look at the IP/ TCP settings. This includes the IP address, Gateway, DNS, and Subnet Mask. Ensure that all these details match those included in the installation guide. Any mismatches can cause a problem. Follow the steps on the installation guide to change the IP/TCP settings.

You can also try removing network devices that are between the modem and the computer. Once you get rid of devices such as network switches and hubs, you can eliminate the chances of these devices being the cause of the problem.

Learn more about the modem

Whether you are using an old or recently purchased modem, you need to understand everything about it. Start by learning what the lights on your device mean.

How to read the lights on a modem
Power light
  • Solid green- This shows that the modem is booted up fully
  • Red-This happens when the device is testing the hardware
  • Amber-It indicates that the modem is testing its software
DSL light
  • Solid green- This shows that the modem is connected to your network
  • Off- It shows that the modem is not detecting the network connection
  • Blinking slowly-This indicates that the modem is searching for the network
  • Blinking quickly-It shows that the modem has not picked up the signal
Internet light
  • Green-It means that the modem is online
  • Solid amber-You need to activate the modem since it is in default mode
  • Red-It shows that the network has rejected the password and username you are using.


The modem lights should be solid green in normal circumstances. If the lights keep on blinking repeatedly, it shows that the modem is not picking a signal as required. You can solve this by conducting an isolation test. This involves eliminating some of the devices on your network one by one. Doing this can help you find out if any of the devices at home connected to the network are causing interference. Other solutions to this problem include power cycling the modem, changing the IP settings, and rebooting your computer.


How long should power cycling the modem take?

Though some people power cycle the modem in only 15 seconds, experts recommend giving it at least a full minute.

Should you add a router into your home network?

Though you can connect the modem directly to your computer, adding a router is advisable. This can help you get wireless network access on different devices. It also secures your home network.

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