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Problems with your internet can be a real hassle to deal with. Not only do you have to get in touch with your ISP’s customer service repeatedly, but you also lose a lot of time. It’s especially a waste of time if you need to work, study, or do anything else that is important to you. CenturyLink, like any other ISP, has its occasional problems. As good as the service is, there is always a chance that you run into some problems along the way.

CenturyLink Fiber service is a very popular option among its customers. Unfortunately, it still doesn’t exempt you from facing Wi-Fi issues at some point. However, before you pick up the phone and place a call to CenturyLink customer service, there are a few things you could try to get your fiber connection to work. We have shared some troubleshooting tips in this blog, so keep reading to find out!

What to Do about a Slow and Unstable Internet Connection?

A slow and unstable internet connection always means that something has gone wrong. Either it’s an equipment issue, a signal issue, or something else. Usually, there are a few things you can do to fix the issue if it is a minor one. Maybe, you can try one of the following things:

  • Check if everything is plugged in – Although this sounds silly and too simple, sometimes, the issue is due to the wire not being plugged in properly. Wires can simply come loose over time so you should check all the wires and ensure they are properly plugged in.
  • Place your router closer to your devices – The router placement is extremely important, especially if you want to ensure even coverage throughout your home. Make sure to place your router in a central location and somewhere closer to your devices without any blockages.
  • Remove physical barriers too close to the router – Blockages like a concrete wall, the refrigerator, wooden cabinets, etc. can significantly impact the signal strength. If there is a physical barrier between your devices and the router, you know what’s causing the internet signals to be weak.
  • Minimize interference from other electronics – Electronic devices tend to produce electromagnetic interference that can interfere with your Wi-Fi signals. Devices like radios, microwaves, TVs, etc. can do this with your Wi-Fi signals and that’s why these devices should be kept away from the router.
  • Regularly check for updates – This doesn’t just apply to routers and modems, rather it also applies to your phone, laptop, TV, and all the other devices that are connected to the internet.
  • Check for the best Wi-Fi channel on your modem – Your neighbor’s Wi-Fi signal could interfere with your Wi-Fi signals causing poor internet. So to avoid this, you should look into the best Wi-Fi channel for your modem.

Check the Router

If your CenturyLink fiber internet problem still persists, despite trying all the things mentioned above, then here’s what you should do. Check for a wire, or more accurately, an Ethernet cable that is connected to your router and the fiber terminal. If your fiber terminal, or ONT, is located outside your home, then maybe it is not directly connected to your router. Rather, it must be connected to a wall jack and then the router.

If the ONT is inside your home, then it will be directly connected to your router via that Ethernet cable. Once you find that wire, you can follow the next steps. However, the steps differ depending on the type of router you have: C4000XG or C3000Z.


  • For this router, the Ethernet cable running connected to the fiber terminal should connect to the back of the router and be plugged into the LAN/WAN port. Once you connect it, the light at the front of the router should be solid green.
  • If the light doesn’t turn on, it means the router is not connected to the network due to not plugging in the cable properly or the ONT has a loss of power. Check the connection once again to ensure the wire is not loosely connected or connected to the wrong port.
  • If the light is still not turned on, check for tripped electrical outlets or breakers. Some circuit breakers can trip if there is an overload with the electrical current.
  • If the light is still off, or it is flashing red and green, call a CenturyLink technician right away since this is something only they can fix.


  • For this router, the Ethernet cable should be connected to the WAN/LAN port on the back of the router and the fiber terminal. The light at the front for the WAN/LAN slot should be solid green.
  • If the light isn’t on, the wire isn’t connected properly. Or there is a loss of power of the fiber terminal. Check the power cord and the Ethernet cable for the modem.
  • Check to see if there are any electrical breakers or outlets with circuit breakers that have tripped.
  • If you see a light for the WAN/LAN slot, but not for the internet, then you should get in touch with CenturyLink’s technical team to resolve the issue.

Check the Fiber Internet Equipment

We mentioned things like fiber terminals or the ONT in the section above. Well, whenever you sign up for a fiber connection, you get some additional specialized equipment. We will be giving you a little bit more detail about this equipment and what they are supposed to do.

Optical Network Terminal (ONT)

To get access to fiber internet, you need an optical network terminal or an ONT, to act as a bridge. Since you can’t directly connect the fiber optic cables to your router, they will instead be connected to the ONT, which will further connect to your router. However, this terminal needs the power to operate. You will have to connect it to your home electrical supply so that it can do its job.

You can install this terminal either inside or outside of your home. If you install it inside your home, it might usually be done in your garage or in a utility closet. As for outside, the ideal location would be behind your home close to the other utility connections. If you are looking for an ONT for your CenturyLink fiber internet connection, you might want to try these two manufacturers: Adtran and Calix.

“Wall wart” power device

We didn’t mention this device before since it is not a necessity for some households. You only need this device if your home doesn’t have a circuit breaker outlet. In that case, the technician that has come to set up the equipment will install the Wall wart. This device has a reset button, just as a GFCI outlet does. If there is a power surge, the circuit will trip causing the power to cut off. Once you’re ready to use it again, just push the restore button.

Battery Backup Units

This is another device that is not a necessity but can be purchased if needed. A battery backup unit, also known as the Uninterruptable Power Supply (UPS) will keep your service running even during a power outage. You can either purchase an 8-hour or 24-hour backup unit. Keep in mind that the backup unit does not guarantee functionality in all outage events, especially if it’s a network issue more than an outage issue.

Frequently Asked Questions (FAQs)

How do I reset my CenturyLink fiber Wi-Fi?

  • From the back of the modem, unplug the power cord and wait for 1 minute.
  • Plug the power cord again and wait for the power and internet light to turn green.
  • Connect your device to the internet and you’re done!

Why does my CenturyLink fiber internet keep disconnecting?

Your CenturyLink fiber connection might be weak due to many reasons.

  • Overheated modem
  • A physical barrier between the modem and your device
  • Too many devices connected to the modem at a time
  • The cords are loosely plugged in