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Level 17/31 Queen St, Melbourne. VIC. 3000

NBN Hybrid Fibre Coaxial (HFC) Troubleshooting (pre-2017)

NBN Hybrid Fibre Coaxial (HFC) Troubleshooting

What do the lights on the nbn™ connection box mean?


  • Link  – Ethernet connectivity between your nbn™ connection box and gateway (router)
  • Online – nbn™ network connection
  • US – Upstream connectivity
  • DS – Downstream connectivity
  • Power – AC power 

Indicator lights: start-up sequence

OffOffOffOffOffNo power to the nbn™ connection box
FlashFlashFlashFlashFlashPower-on self test
OffOffOffFlashOnDownstream search
OffOffFlashOnOnDownstream found; upstream search
OffFlashOnOnOnDownstream and upstream found; retrieving setup information from nbn
OnOnOnOnOnReady for service

Indicator lights: start-up sequence

OnOnOnOnOnReady for service
OnOffFlashFlashOnNot connected to the nbn™ network
OnOnFlashFlashOnFirmware upgrade
OffOffOffOffOffNo power to nbn™ connection box


If any of the services provided through your nbn™ connection box stop working (e.g. internet or phone), first check the following:

  • Everything is plugged in and turned on?
    • Is your nbn™ connection box power cord plugged in firmly at both ends? 
    • (Always keep your nbn™ connection box plugged into AC power and connected to the wall outlet.) 
  • The indicator lights on your nbn™ connection box
    • The Power and Online lights should be on.
    • The Link light should either be on or flashing.
    • The Downstream and Upstream lights should be on.
    • If the Power light flashes for more than 30 minutes, contact your service provider.
  • The cable and device connections
    • Coaxial fly lead: this should not be pinched, kinked or bent sharply as it can cause a break or short in the cable (and the cable may have to be replaced).
    • Splitter (if you have one): make sure the splitter(s) between your nbn™ connection box and the wall outlet is (are) connected correctly.
    • Ethernet cable: make sure the Ethernet cable is correctly connected.
    • Your own equipment and devices: check that all cables and power points are switched on and connected correctly
  • External equipment 
    • Has external nbn™ supplied equipment been damaged? For example, a fallen branch may have damaged the coaxial cable connection or associated outside equipment, such as the nbn™ utility box. If you think this may be the case, do NOT try to remove or repair the cable yourself. Contact your service provider immediately.

Still having issues?

In order to be able to progress your fault, we typically need the following information, having this information will allow us to progress the fault quickly and avoid any additional information being sought.

  • Description of the issue you are having (e.g. Internet service goes offline and you are unable to access any websites)
  • When the issue happens what status lights are on with the NBN NCD (see Indicator Lights table above)
  • Is your router powered on?
  • If possible please list the MAC address for your router, typically this is listed on a barcode on the bottom of the router.

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