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HFC Modem Lights Explained
Last Updated: Sunday 14 Sept 2025
There are 2 versions of the Hybrid Fibre Coaxial (HFC) modem, also called an Network Termination Device (NTD).
Check the images below for the version that looks like yours.
| Power | Downstream | Upstream | Online | Meaning |
|---|
| Off | Off | Off | Off | No power to the NBN connection box |
| On | Flashing | Flashing | Off | Firmware is updating |
| Flashing | Off | Off | Off | There is a problem with the NBN connection box |
| On | On | On | On | The NBN connection box is online |
| Power | Downstream | Upstream | Online | Meaning |
|---|
| Off | Off | Off | Off | No power to the NBN connection box |
| On | Flashing | Flashing | Flashing | Power-on self test |
| On | Flashing | Off | Off | Downstream search |
| On | On | Flashing | Off | Downstream found, upstream search |
| On | On | On | Flashing | Downstream and upstream found - retrieving setup information from NBN |
| On | On | On | On | Ready for service |
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