Yes, you need a (preferably corded) phone plugged directly into the test sockt. No filter, no router. If it doesn't work then it is a line fault to report to your
phone line rental company. It would be a good idea to do the
Quiet line test first. 17070 option 2 - it should be silent. (I assume in fact the line is with TT as well as the broadband). Don't mention the broadband issue as that could send them off on the wrong track.
It's unlikely to be the incoming wire detached inside the rear section of the master, but even if it is that is their problem - they need to get Openreach out to fix it.
It is more likely it is outside the premises.
But if the phone works fine, back to square one. A broadband issue.
You can get a cheap corded phone from many places. Useful to have. We have one tucked away in a cupboard.
My broadband basic info/help site - www.robertos.me.uk
My domains,website and mail hosting - Tsohost.
Internet connection - IDNet Home Starter Fibre.
Live BQM.
"Where talent is a dwarf, self-esteem is a giant." - Jean-Antoine Petit-Senn.