NBN not working? What to check, step by step

The checks depend on your connection, so start here:

• FTTP (fibre to the premises): an nbn connection box on a wall, fed by a fibre cable, often with an Optical light and UNI-D ports.
• FTTC (fibre to the curb): a small nbn connection device that plugs into your phone wall socket, with your modem plugged into it.
• HFC (hybrid fibre coaxial): an nbn connection box joined to a coaxial (TV-style) wall outlet.
• FTTN or FTTB (fibre to the node or building): no nbn box. Your modem plugs straight into the phone wall socket.
• Fixed wireless: an antenna on the roof and an indoor connection box.

FTTP

• Power off: the box has no power. Check the power supply is plugged in and switched on.
• Optical off: the box isn’t connected to the nbn network. It should be solid green when connected.
• Alarm red: the box has a fault. Contact your provider.
• UNI-D: your modem must be in the port your provider activated, usually UNI-D 1.

FTTC

• The connection device is powered by your modem through the phone line, so the modem must be on and connected.
• Power should be on (blue on common models), and the DSL light shows when it’s talking to the network.
• A red Connection light means a reverse power problem. Check the cables and modem, then contact your provider.

HFC

• Lights are Power, Downstream, Upstream and Online. All four should be solid green.
• After a restart, allow up to 30 minutes for them to settle.
• If Online stays off while Downstream and Upstream flash, check the coaxial cable is screwed in firmly at both ends.

FTTN and FTTB

• Check the DSL or Broadband light on your modem. If it’s off or flashing for a long time, the modem isn’t syncing with the network.
• Plug the modem into the main phone socket with no extension cords, splitters or old filters in between.

Fixed wireless

• A solid red Status light means a system fault. Restart the box first.
• Check the signal strength lights and that the cable from the outdoor antenna is secure.

1. Check for an outage on your provider’s app or website.
2. Restart in order. Turn off the modem and nbn box, wait a minute, turn the nbn box on, then the modem once the box has settled.
3. Check every cable, including power, the cable from the nbn box to the modem’s WAN port and the phone or coaxial lead.
4. Test with a cable. Plug a laptop into the modem with an ethernet cable. If that works, the internet is fine and the issue is Wi-Fi.
5. Try another device to rule out one phone or laptop being the problem.
6. Check the modem’s internet or WAN light. If it’s off while the nbn box looks normal, the modem may have lost its settings.
7. Factory reset only as a last resort, and only if you have your provider’s setup details handy.

Likely a network or provider fault if the nbn box shows a fault light, no device connects even by cable, or the modem can’t get an internet connection after a restart.

Likely home Wi-Fi if a cabled device works, only some rooms drop out, or only one device struggles. Common causes are modem placement, interference, an overloaded old modem or devices stuck on a weak band. Our guides on Wi-Fi connected but no internet and the Wi-Fi troubleshooting flowchart walk through those fixes.

Report faults to your internet provider, not to nbn directly. Your provider runs line tests and books an nbn technician if needed. Before you call, note:

• Your connection type and which lights are on, off, red or flashing
• When the problem started and whether it comes and goes
• What you’ve already tried, including the cabled test

If the provider doesn’t fix it in a reasonable time, make a formal complaint to them. If that doesn’t resolve it, you can escalate to the Telecommunications Industry Ombudsman.

If the nbn side checks out but your Wi-Fi, printer or computer still won’t cooperate, HelpByExperts offers fixed-price Wi-Fi and computer fixes at /fix-my-computer.