Table of contents(16)+
- 01The 30-second test
- 02What each AT&T modem light means
- 03Fix 1: Check for an AT&T outage before anything else
- 04Fix 2: Reseat the fiber or DSL line into the gateway
- 05Fix 3: Power-cycle the gateway (and wait the full 10 minutes)
- 06Fix 4: Factory-reset the gateway (last resort)
- 07Fix 5: Replace the gateway or escalate to AT&T
- 08Quick fix by red-light symptom
- 09Frequently Asked Questions
- 10What does a red light on my AT&T modem mean?
- 11Why is my AT&T Broadband light red?
- 12How do I fix a red Service light on my AT&T gateway?
- 13How long does an AT&T modem take to reconnect?
- 14Does a flashing red light always mean an outage?
- 15Can I still control my TV while the modem is red?
- 16Related guides
A flashing red light on your AT&T modem means the gateway lost its internet signal. On most gateways like the BGW320 and BGW210, a red Broadband light points to a fiber or phone-line problem, while a red Service light means the line is up but the internet won't authenticate. Check for an outage first, then power-cycle the gateway.
I've set these up more than once — a BGW320-500 on AT&T Fiber and an older Pace 5268AC on DSL. The red light scared me the first time. But it almost always traces back to three things: an area outage, a loose line, or a gateway that just needs a reboot. Here's how I work through it, fastest check first.
The 30-second test
Before you unplug anything, look at which light is red. The pattern tells you where the problem is.
- Power light red: the gateway itself failed to boot. A power-cycle usually clears it.
- Broadband light red (or Broadband 1 / Broadband 2 on the BGW320): no signal is reaching the gateway. Think outage or a loose cable.
- Service light red: the line is fine, but the internet won't authenticate. This one usually needs AT&T.
Stuck without internet while AT&T sorts out the line? Your local Wi-Fi often stays up even when the Broadband light is red. If you've lost your TV remote in the shuffle too, HiRemote (free, 4.4 stars on the App Store) controls a Hisense TV straight over your home Wi-Fi — it talks to the TV on the local network, so it keeps working even while your internet is down.
What each AT&T modem light means
AT&T gateways use the same color code across models. Here's the quick reference. For your exact model's light guide, see AT&T's gateway support pages.
| Light | Solid green | Red or flashing red | What to do |
|---|---|---|---|
| Power | Gateway is on and healthy | Boot failure or overheating | Power-cycle (Fix 3) |
| Broadband | Line signal locked | No fiber/DSL signal | Check outage, reseat line (Fix 1–2) |
| Service | Internet authenticated | Line up, no internet | Power-cycle, then call AT&T (Fix 3, 5) |
| Wi-Fi | Wi-Fi is broadcasting | Wi-Fi radio off or fault | Reboot; check the Wi-Fi button |
Fix 1: Check for an AT&T outage before anything else
A red light is often not your fault at all. Rule out an area outage before you touch a cable.
- Open the Smart Home Manager app → tap Network → look for a red outage banner.
- No app? Go to att.com/outages and sign in with your AT&T ID.
- Still unsure? Call AT&T at 800-288-2020 — the automated line reports known outages by address.
When this won't help: if no outage is listed, the problem is on your end. Move to Fix 2.
Fix 2: Reseat the fiber or DSL line into the gateway
A half-seated cable is the most common red-Broadband cause I see. Reseat both ends.
- Fiber (BGW320): the thin green cable plugs into the green ONT/Fiber port. Unplug it, check the tip for dust, and click it back in firmly.
- DSL (Pace 5268AC and older): check the grey phone line in the Broadband port and the wall jack. Swap the cable if you have a spare.
- If you have a separate ONT box (garage, closet, or basement), confirm its power light is green too.
When this won't help: a chewed or kinked line needs replacing — that's an AT&T job (Fix 5).
Fix 3: Power-cycle the gateway (and wait the full 10 minutes)
This clears most red Service lights and boot faults. The trick is patience.
- Unplug the gateway's power cord. Wait a full 30 seconds.
- Plug it back in. Do not keep unplugging it — one clean cycle is enough.
- Watch the Broadband light: red → flashing green → solid green. Then Service turns solid green.
- Give it up to 10 minutes. Fiber sync is slow, and pulling the plug early restarts the whole wait.
When this won't help: if it never leaves red after 10 minutes, stop rebooting. The line or hardware is the issue — go to Fix 5.
Got a Hisense Roku TV in the room and no remote while you wait? You don't even need the app — open the free browser remote at hiremote.app/hisense-roku-tv-remote, type your TV's IP address, and control it from any phone or laptop on the same Wi-Fi. No download, no account.
Fix 4: Factory-reset the gateway (last resort)
Only do this if Fixes 1–3 failed. A reset wipes your settings, so save it for last.
- Find the small Reset pinhole on the back of the gateway.
- Press it with a paperclip and hold for 10+ seconds until the lights blink and it reboots.
- The gateway rebuilds from scratch — allow several minutes for all lights to settle green.
When this won't help — and the warning: a reset erases your custom Wi-Fi name, password, and any IP Passthrough setup, so you'll reconnect every device. If your red light is a line or outage problem, a reset changes nothing.
Fix 5: Replace the gateway or escalate to AT&T
If Broadband or Service stays red after everything above, the fault is theirs, not yours.
- Call AT&T at 800-288-2020 or start a chat in Smart Home Manager.
- Ask them to run a line test and check your ONT remotely.
- A faulty gateway swap or a tech visit is free when it's AT&T's equipment.
Once the internet is back, you may need to reconnect your streaming gear. If your TV drops off, see our guide on fixing a Hisense TV that won't connect to Wi-Fi, or how to reconnect a Hisense TV to Wi-Fi.
Quick fix by red-light symptom
| What you see | Most likely cause | Try first |
|---|---|---|
| Broadband red, no outage listed | Loose or bad line | Fix 2, then Fix 3 |
| Broadband red, outage confirmed | AT&T network down | Wait it out (Fix 1) |
| Service red, Broadband green | Auth/registration glitch | Fix 3, then Fix 5 |
| Power red | Boot or hardware fault | Fix 3, then Fix 4 |
| Still red after a 10-min reboot | Hardware or line failure | Fix 5 |
Frequently Asked Questions
What does a red light on my AT&T modem mean?
A red light means your gateway lost its internet connection. The exact cause depends on which light is red: a red Broadband light points to a fiber or DSL line problem, a red Service light means the line works but the internet won't authenticate, and a red Power light signals a boot or hardware fault. Start by checking for an outage.
Why is my AT&T Broadband light red?
A red Broadband light means no signal is reaching your gateway. The two common causes are an AT&T area outage or a loose or damaged fiber or DSL cable. Check att.com/outages first, then reseat the line at both the gateway and the wall. If it stays red after a reboot, the line or ONT needs an AT&T tech.
How do I fix a red Service light on my AT&T gateway?
Power-cycle the gateway first. Unplug it for 30 seconds, plug it back in, and wait up to 10 minutes for the Service light to turn solid green. A red Service light means your line is fine but the internet won't register, which a reboot often clears. If it stays red, call AT&T to re-provision the line.
How long does an AT&T modem take to reconnect?
Give it up to 10 minutes after a reboot. Fiber gateways like the BGW320 sync slowly — the Broadband light goes red, then flashing green, then solid green before the Service light comes on. Don't unplug it early. Pulling the power mid-sync restarts the entire wait from zero.
Does a flashing red light always mean an outage?
No. A flashing red light can mean an outage, but it can also be a loose cable, a gateway that needs rebooting, or failed hardware. Check att.com/outages or the Smart Home Manager app to confirm an outage first. If none is listed, the problem is on your end and the fixes above apply.
Can I still control my TV while the modem is red?
Yes, often you can. A red Broadband light kills streaming, but your local Wi-Fi radio usually stays on. Because HiRemote controls a Hisense TV over your local network — not the internet — it keeps working even while AT&T is down. Streaming apps won't load until the internet returns, but volume, power, and menu control still work.
