Learn what each light on your Adtran ONT means—from power and fiber signal to LAN and phone service—and how to quickly troubleshoot issues.
Power
What it means:
This light shows whether your ONT is getting power.
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Solid Green: The ONT is powered on and functioning normally.
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No Light: The ONT is not receiving power.
What to check:
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Make sure the power cable is securely plugged into both the ONT and a working wall outlet.
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If you’re using a power strip, check that it’s turned on.
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Try plugging the ONT into another outlet to rule out a power issue.
LAN
What it means:
This light indicates whether your ONT is connected to a device—usually your eero™ router—via Ethernet.
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Solid Green: An Ethernet device (like your router) is connected and transmitting data.
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No Light: The ONT is not detecting an Ethernet connection.
What to check:
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Ensure the Ethernet cable is firmly connected between the ONT and your eero™.
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Try a different cable or port if needed.
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Restart both the ONT and your eero™ router.
Optical
What it means:
This light shows whether your ONT is receiving a signal from Surf’s fiber network.
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Solid Green: The ONT is receiving a proper fiber signal.
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Red or No Light: No fiber signal is being received.
What to check:
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If this light is off or red, try restarting your ONT by unplugging it for 30 seconds and plugging it back in.
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If the light doesn’t return to green, log in to your Surf account to check for any reported outages in your area.
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Still having issues? Contact Surf support.
Voice/POTS
What it means:
This light only applies if you have Surf’s home phone (VoIP) service.
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Solid Green: The phone service is active and registered.
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No Light: Phone service is not in use or not connected.
What to check:
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If you have phone service and this light is off, check that your phone is properly connected to the ONT.
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Make sure your service is active by logging into your Surf account.
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Contact Surf support if the light remains off and you’re experiencing issues.
What If All Lights Are Off?
If none of the lights are on:
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Check that the ONT is plugged in and the outlet has power.
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Try another outlet or test the outlet with another device.
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If the ONT still shows no lights, it may be a power supply issue.
Still Need Help?
We’re here for you.
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Call us at 1-866-274-6381
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Visit our Help Center
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Use live chat on our website
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Create a support ticket by logging into your Surf account.
Surf Internet delivers fast, reliable fiber internet—backed by exceptional local support.