connecting TP Link AC1900 to super fibre

Hi, I wanted to upgrade from the Superrouter due to wifi issues, and picked up a TPLink AC1900 on Amazon special deals.

But - it won't connect to the internet!

I have entered the settings manually from here ...

http://community.talktalk.co.uk/t5/Community-Help-Articles-beta/Setting-up-a-Non-TalkTalk-Router/ta-p/1324129  

The internet light on the router flashes mayne 20 times, the web interface says it is initialising, then the light goes off, and the interface says 'Disconnected', then it tries again, and again, and again...

Any clues please?

Thanks.

Simon