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BT Smart Hub 2 Flashing Purple: Check the Broadband Cable and ONT Link

BT users in the UK may encounter this specific state: The BT Hub keeps flashing purple and devices see Wi-Fi but cannot reach the internet. This guide separates its most relevant causes.

Quick Answer

Identify Full Fibre versus copper broadband and inspect the cable in the WAN or broadband port. Then reconnect only the correct supplied cable, allow the Hub to resynchronise, and escalate a missing external fibre signal. Finally a steady blue Hub light and a page loading from both Ethernet and Wi-Fi confirm recovery.

BT troubleshooting — UK. The BT Hub keeps flashing purple and devices see Wi-Fi but cannot reach the internet. The important distinction is whether this failure belongs to the provider connection, a particular device or an account or application session. Those branches need different repairs.

This guide focuses on BT Smart Hub 2 Flashing Purple, not a one-click reset. For this connection, the order of evidence matters: provider line or fibre status, modem registration, router WAN state, then the household devices. Treat these as separate checkpoints.

What this failure tells you

What you see: The BT Hub keeps flashing purple and devices see Wi-Fi but cannot reach the internet. Record when it begins, whether it happens after startup or only when using a particular feature, and which devices still behave normally. If the system displays an error number, photograph its exact wording instead of assuming a similar-looking number means the same thing.

First discriminating check: Identify Full Fibre versus copper broadband and inspect the cable in the WAN or broadband port. Use the actual model and service type because the same colour or phrase can mean different things on older and newer hardware.

Why this problem happens

On Full Fibre, compare the Openreach modem Ethernet link with the Hub WAN port; on copper, inspect the DSL lead and filter. This identifies a testable hypothesis, not proof that a particular component is broken. Check the provider’s current service notices and any recent change of router, SIM, handset, app version or account entitlement.

Router Wi-Fi association, local Ethernet link and provider access registration are three separate states. Compare one Ethernet client with one Wi-Fi client while observing the modem WAN, DSL, optical or gateway indicator.

Observation What it may indicate Next useful test
Wi-Fi visible, all clients offline Router local radio works but upstream service may be absent Read the model-specific WAN or connection indicator
Ethernet works, one wireless device fails Wireless profile, range or local client issue Compare gateway, DNS and another authorised client
No upstream link indicator Physical line, provisioning or provider network issue Follow service-status and line tests before resets

Protect working settings and data

Avoid factory reset as a first step: it can erase Wi-Fi names, pairing, voice settings or provider configuration. Document the original state and protect account details. Review the provider’s own equipment reference and preserve any working account session, local recordings and connection parameters.

Collect only necessary evidence: Write down the hardware generation, light pattern, line type, elapsed startup time and provider outage reference.. This will help distinguish a repair from a temporary recovery caused by a service coming back online during testing.

Step-by-Step Troubleshooting

Choose the Beginner route for safe checks or the Advanced route for isolating the failing layer.

Record the observable failure

The BT Hub keeps flashing purple and devices see Wi-Fi but cannot reach the internet. Take a screenshot of the actual on-screen state or write down the LED or message exactly. Make a note of what worked immediately beforehand and whether the symptom affects every device.

Find the correct equipment or account

Identify Full Fibre versus copper broadband and inspect the cable in the WAN or broadband port. Work with the named provider and actual equipment generation. If the issue follows a switch or move, note that transition before making any changes.

Make one reversible change

Reconnect only the correct supplied cable, allow the Hub to resynchronise, and escalate a missing external fibre signal. Keep the original configuration available for rollback. Change only one condition, wait for the normal startup or provisioning window, and avoid repeated resets.

Retest the original problem

A steady blue Hub light and a page loading from both Ethernet and Wi-Fi confirm recovery. Repeat the same operation that failed with the same intended account, programme or connection. A success in a different application does not by itself prove that this issue has been fixed.

How to choose the next branch

Reconnect only the correct supplied cable, allow the Hub to resynchronise, and escalate a missing external fibre signal. If the first controlled attempt has no effect, stop repeating it: a stable upstream fault may require network provisioning, hardware replacement or a provider field test that is not available to customers.

If a second supported device or connection works, compare only the differences: the selected network, pairing method, app build or account access. Do not change several variables simultaneously; that makes the real cause difficult to identify.

Verification: what counts as success

Pass condition: A steady blue Hub light and a page loading from both Ethernet and Wi-Fi confirm recovery. For a recurring fault, repeat the same workflow over the interval during which it normally fails; a single webpage loading once is not a complete test.

Keep a before-and-after record that includes the original failure, current indicator or app result, and one cross-check with a second permitted device or network. Do not describe the repair as confirmed if you could not reproduce the original failure.

Solution Checklist

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If the service stays offline

Ask BT support to review the relevant service status using a ticket that includes the date, connection technology or device model and reproducible symptoms. Mention the provider-specific check you already performed so that support can route the case to the correct equipment, provisioning or application team.

If a setting change made the situation worse, restore the documented previous configuration. Avoid clearing all stored settings, deleting mobile profiles or running a factory reset unless official support confirms it is necessary and you have the information required to reconfigure the device.

Official Resources

BT support and troubleshooting documentation

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