Waterloo: After the Power Cable Was Knocked Out, a Telstra DSL Line Came Back with a Red Light, WiFi but No Internet

Returning client · WaterlooTelstra 100M DSLASUS routerRed indicator lightWiFi but no internetReset + provider refresh

A returning client in Waterloo — we had installed their router back in April. They knocked the power cable out, plugged it back in, and the router came up with a red indicator: devices could still join the WiFi, but nothing would load. Most routers recover a line on their own once power returns. When one does not, it is worth knowing what the realistic causes are before you buy a replacement.

Where the chain broke · WiFi was never the problem

Telstra DSL line

100M

→

ASUS router WAN

red

Bottleneck

→

Router WiFi radio

→

Your devices

no internet

This is the classic shape of a WiFi-but-no-internet fault. The wireless radio inside the router comes back up on its own after a power cut, so phones and laptops still see the network and still get a local IP. What did not come back was the WAN side — the router never re-established the line with Telstra, which is what the red indicator was telling us.

What happened

This one was a returning client — we had installed the router for them back in April. They messaged around midday and we went out that afternoon.

Location: Waterloo, Sydney. Provider: Telstra. Router: ASUS. Plan: 100Mbps. Connection: DSL over the phone line.
What they reported: the power cable got knocked out; after plugging it back in, devices could connect to the WiFi but had no internet, and the indicator light was red.
Handled on-site rather than remotely, because separating a router hardware fault from a provider-side fault needs test gear you can swap in.

Why a router sometimes does not come back after a power cut

For the large majority of routers, once power is restored the unit re-establishes the connection on its own — that is the normal behaviour and it is why most people never think about it. When it does not come back, the realistic causes are:

Router hardware. Unstable current or voltage during the interruption can leave an internal component misbehaving. Worth noting: some higher-end routers, ASUS units among them, draw more power than an ordinary router, which gives unstable supply a slightly better chance of causing trouble.
The provider side. The session the router had with the provider may need to be refreshed before it will come back.
Other equipment in the flat — an NBN box or an Opticomm device sitting in front of the router can also be the one that did not recover.

Which of the three it is cannot be guessed from the light alone. You bring known-good gear and rule them out one at a time.

WiFi but no internet vs no WiFi at all

	WiFi visible, no internet	No WiFi at all
What it means	The router is alive; the link to the provider is not	The router itself is down or its wireless radio has failed
Usually points at	WAN side: the line, the provider session, or an upstream box	Power, hardware failure, or wireless turned off
First thing to check	The WAN or internet indicator, and whether a wired device also has no internet	Whether the power indicator is on at all
This case	Red indicator, WiFi joinable, no internet	Not applicable

How we isolated it, step by step

Confirmed the symptom on-site

WiFi joins fine, red indicator, no internet

Checked power and the DSL phone line seating

Power restored, line physically seated

Ruled out other equipment in front of the router

No upstream box holding it down

Reset the ASUS router

Router side cleared

Had Telstra run a remote refresh on the service

Line re-established, back online

What to try before calling anyone

If your light goes red after a power interruption, a few minutes of your own can save a visit:

Give it time. A DSL line can take several minutes to re-synchronise after power is restored — do not judge it in the first thirty seconds.
Power everything down in order, wait a full minute, then bring the upstream box up first and the router second.
Plug a laptop into the router with a cable. If the wired device also has no internet, this is not a WiFi problem and you can stop fiddling with the wireless settings.
If the indicator is still red after that, call the provider and ask them to check the service and refresh it from their side — that is exactly what fixed this one.

Result

Root cause was on the WAN side, not the WiFi: after the power interruption the ASUS router never re-established the line with Telstra, which is what the red indicator meant. Resetting the router plus a remote refresh run by Telstra on their side brought the 100Mbps DSL connection back. Worth remembering that higher-powered routers are a little more exposed to unstable supply than ordinary ones.

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Waterloo: After the Power Cable Was Knocked Out, a Telstra DSL Line Came Back with a Red Light, WiFi but No Internet

What happened

Why a router sometimes does not come back after a power cut

What to try before calling anyone

Related

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