Fios Box Blinking Red & Green Light, Flashing Green? Try This!

What does the light on your Fios Box mean, what happens when it flashes red and green, or sometimes just green?

The light does tell us about the state of the line connection and being a member of the industry myself, I can tell you that they help us to diagnose the issue and let the troubleshooting be completed in a timely manner.

Fios users are not much aware of what these are, what they mean, how they affect the service, and what to do to fix the problem.

The following guide will provide you with a detailed description of what is causing these lights to flash on your Fios box, whether it be the Fios One, Fios Mini, or any other Fios main box.

Fios Box Lights
Fios Box Lights

In a nutshell, when the green light on your Fios box keeps flashing, this indicates a firmware update is either being prepared to be installed or is in the process of being installed, usually it stays for only a short time.

If it stays for a longer period of time, then the update is not being installed for some reason and must be manually installed.

Now, what does the red flashing light on the Fios box mean? 

If you see the red flashing light, it means that your fiber connection is experiencing some problems due to a faulty ONT (Optical Network Terminal) box or some damage to the fiber cable.

Fios Main Box Lights
Fios Main Box Lights (Image: Verizon Fios Forums)

However, you shouldn’t have to worry about it as I will explain how it happens in more detail and I will also help you to fix the issue.

Why Is My Fios Box Flashing Red And Green?

According to your Fios box, this is what you are seeing: 

  • The power light is green. Fail (ONT,  Second) light is blinking red.
  • The power light is green, ONT light is flashing Green

There are two scenarios, in which there is a flashing red and green light on the Fios box, and in another, there is a flashing green light only along with a stable green light on the Fios box.

Fios Mini Box

Let’s now take a look at the reason behind these flashing lights on your Fios box. 

There are different lights on the Fios Main box, listed below in order:

  • Power
  • Battery
  • FAIL
  • Video
  • Data
  • Network
  • Management
  • POTS

Flashing Red and Green Light On Fios:

When we refer to the flashing red and green light, it means that the power light is “stable green” and the fail light is “flashing red”.

  • In this case, it indicates that there could be a fault in the line or in the ONT box itself.

Basically, when the Fios One ONT box is red, it means that the ONT isn’t seeing fiber optic light either because of a broken fiber line or a faulty ONT box connection.

Flashing Green Light On Fios Mini:

Taking the second scenario where the Fios Box has the green flashing light, we are referring to the green flashing light as the “Fail” light.

  • In this case, it means that the Fios box is updating itself or is preparing for the update process by downloading the update.

So in simple terms, 

In the Fios One Main Box, the flashing green light indicates that an update is downloading or partially downloaded.

Generally, it gets sorted when the update completes, and it doesn’t affect your main connection, but if it took a couple of hours already, it means your box is not accepting the update.

Now that we know why these flashing red and green lights are happening, as well as when they only flash green, let’s see what we need to do to fix this.

What To Do When Fios Box Has Flashing Red Green Light?

Fios Box All Lights

Due to the differences between both scenarios, I will provide a solution for each separately. 

Firstly, let’s take a look at the Fios Box flashing green light issue. 

Knowing that the flashing green light means there is an update that needs to be downloaded or is partially downloaded, we can take action.

The update should go by itself, but if it does not, then that means the update that is being pushed is not being accepted by your box.

In that case, we’ll need to troubleshoot.

If the green light is flashing on your Fios main box, you must take the following steps:

  • Power Cycle
  • Remove affected Fios Mini Box Manually
  • Reset Router
  • Reset Fios Gateway 
  • Reset ONT

However, before jumping to main troubleshooting, first, try replugging the cable.

Oftentimes, just replugging the entire connection is enough to clear any minor glitches which can lead to the flashing light issue and solve it.

To begin, unplug your router and the box for a minimum of 30 seconds. Once the router is back online, you can re-plug the FiOS One box. 

Power Cycle

In some cases, power cycling the router will force the box to retry the download and clear its memory glitch.

After you do that, the update will be pushed again for installation.

Here’s what you have to do:

  1. Remove coax cable
  2. Power down router
  3. Reboot router
  4. When all connections on the router are ok, power STB back up
  5. Reattach coax to STB. 
  6. STB should update, green blink should go away.

Alternatively, you could try setting > system > Fios TV one settings and disconnect the mini from your main box.

After disconnecting the mini, reboot the main and add it back in. 

Using this method, you can also fix the flashing green light problem for your Fios mini, Fios one, or another Fios box.


In the event that rebooting doesn’t resolve the issue, you may need to perform a reset.

The reset operation can be done on a router, an ONT, as well as a Fios gateway.

The first step is to reset the router, and here’s how to do it.

  • To fix the problem, go to the affected TV One Mini menu
  • Next, Customer Support 
  • Reset your router after selecting Internet.

Upon completion of this step, check if the problem persists and if so, go to the next reset step.

If the router has been reset and the ONT box has not been reset, you need to press the little reset button on the power brick to reset it.

The last step is to reset all your FiOS ONE boxes. 

First reboot the DVR, After the DVR has booted, plug in the FiOS Mini boxes (keep them unplugged until the DVR is fully functional).

By doing this, you will fully reset all of your network connections. 

You should be able to resolve your issue with this. 

Try recording an episode from the DVR and replaying it after it has been done. 

Test network connectivity and quality using a Mini box (if you have one) after replaying a previous recording from the DVR.

Many Fios users had reported the flashing green light problem, and that fixed the problem. 

Remove Affected Fios Mini 

It is also possible to solve the flashing green light issue on Fios boxes by manually removing the affected Fios Mini and adding it again.

Here’s how you can do it:

  • On the main box, click the menu
  • The affected mini should be removed
  • If you add the back of the affected mini, the green flashing light will not appear any longer.

Hopefully, the flashing green light issue on your Fios has been resolved, let’s now take a look at the flashing red light issue.

How To Fix Flashing Red Green Light On Fios?

Generally, a red fail light indicates that the ONT is not receiving fiber optic signals, but it could also be a hardware issue, such as due to an old ONT box.

This usually means that there is a bad/cut fiber line somewhere in your network.

If that’s the case, there’s nothing you can do from your end, as Verizon Fios tech support will have to intervene.

Therefore, you need to contact support and report it in order to get that fixed. 

In addition to inspecting your ONT model, the tech people will visit and fix the entire line, regardless of whether your ONT is an older BPON model or a newer GPON model.

You might also be able to switch it for free to the most recent version.


Hopefully, the above guide helped you understand why Fios boxes flash green and red or only flash green.

It is not a big concern if your Fios Mini only has flashing green lights because that happens when the automatic update fails and can be easily fixed at home by following the troubleshooting steps listed above.

In cases where it flashes red and green, you should contact Verizon Fios support for help in rectifying the problem as it is usually caused by damage to the fiber cable or faulty ONT units.

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