So you were trying to use your AT&T Broadband when it stopped working and a light flashed green then red. What would cause the broadband to blink like that and why isn’t it working properly? 

Generally, your AT&T broadband light will flash green then red when there’s a connectivity problem. It could be the result of anything from your modem malfunctioning to unplugged or damaged cables. You must troubleshoot each possibility to find out which is yours.  

If your AT&T broadband light has suddenly started flashing green then red and you’re not sure what to do, fear not, for we have you covered. In our guide below, we first explain exactly why your broadband light might blink this way. Additionally, we will walk you through three easy troubleshooting steps that will hopefully get your broadband back up and running in no time. 

What Causes My Broadband Light to Flash Green then Red?

Generally, problems with your AT&T Broadband flashing green then red are the result of some kind of connectivity issue. Sometimes this issue can be resolved the old fashion way–by resetting your gateway–however other times the problem requires a more nuanced approach to fixing it.  

Troubleshooting Connectivity Problems With AT&T Broadband

Troubleshooting is the key to figuring out what the problem is and fixing it. In the following sections we’ll give you our suggestions on how you can start troubleshooting your connectivity issues.

Unplug and Replugin Your Modem

In troubleshooting, it’s always best to start with the simplest solutions first and then work your way to the more complex ones. For this issue, the simplest approach is to reset your modem

To do this you can either hold down the reset button or unplug the unit itself, wait thirty seconds then plug it back in. 

Now you just boot it back up and see if the problem is resolved. If it is, congrats, you’re done faster than you expected. If it’s not, try out our next troubleshooting tip. 

Test the Connections on Your Modem 

If simply restarting your modem doesn’t work, you should test all of the other connections. The easiest way is to unplug everything from the modem and then plug it back in.

As you go, look for cables that might be a little loose or damaged. There’s a whole litany of ways cables can become damaged.  If you have pets or mice, there’s even a chance that some of them have been chewed on. Essentially, you’re just looking for any signs that a cable may not be functioning. 

Once everything has been plugged back in, start up the modem and see if your connection is now working. 

Call Line Support to Test Connections 

Looking for external damage on your cables is one thing, but what if the problem is internal? It could be something as simple as a short. How do you tell if that’s the case?

Fortunately, you can call AT&T at 1-800-288-2020 and have them run a line check for you. Depending on what they discover they may offer to send a technician to help you. 

What Lights Should Be On My AT&T Modem?

One last thing that is well worth knowing in the future, is what lights should be on with your Modem? It can be easier to spot problems if you know what it should look like. 

When your modem is functioning properly, all the lights should be on in solid green. When lights are blinking, it is trying to tell you something. 

Also, keep in mind that the power light may turn yellow when it is upgrading. If that’s the case it is also still functioning properly. 

How Do You Know if Your Modem is Bad? 

Generally, when a modem goes bad there is more than one problem that presents itself. If it begins making weird noises, can’t download things it used to be able to easily, has connectivity problems often, or begins turning itself off and on despite having a good power cable, chances are you will need a new one. 

So Really, Why is My AT&T Broadband Light Flashing?

So in summary, if your AT&T Broadband light is flashing green then red, chances are you have a connectivity issue. To resolve the issue, you’re going to want to troubleshoot your modem and the cables that are plugged into it. 

You can start by simply resetting the modem and seeing if it comes back on properly. Of course, you can also unplug the modem, as well as all the cables plugged into it, to both reset it and ensure no cables were loose or damaged. Usually, this problem is an easy fix. If you have serious trouble, however, don’t hesitate to call AT&T support at 1-800-288-2020.