In reply to a post by Zarjaz:

Go on, it's only two screws, you know you want to

Three, actually.

There are three holes, but only two screws - look closer

Well we never use the landline (when other people say they do, I almost don't believe them. Who uses landlines still?! *Awaits hate mail*)

We have two Sky boxes which are in theory meant to be connected to the phone line, but neither have been for at least a year, and if I had to connect them temporarily I'd get a crazy long phone cable from somewhere.

Yeah, Brookzy told me that ........ If it's loose screws that are the issue, maybe he should speak to ADSLMax ?

I hadn't read that far when I replied.

Ring Capacitor? hmmm, If this isn't the master, shouldn't this be a 2/3A aka a Secondary Socket?

It's not the master, but it's an extension that mysteriously works when the master is disconnected.

But with a ring capacitor it is probably detrimental to the line when connected anyway?

Im trying to ascertain where the bridge tap is but am having no success. I'd be quite happy to have the drop wire connected straight to the modem via a filter but I can't see that happening.

Could it be that this is the wiring arrangement?

https://community.bt.com/t5/image/serverpage/image-i...

In which case, could I buy an NTE5, an Openreach fibre plate, install these on the bedroom socket and remove the current master socket?

That is the probable arrangement, yes. But No! You cannot mess with that - neither legally nor sensibly.

You need to leave it to the engineer. Suggest to them on arrival that if it is difficult to find and fix, you would be perfectly happy if the master socket was repositioned wherever, as suggested earlier by Zarjaz, with a direct feed from that external box and cabled externally. All other sockets disabled.

You already have the NTE5, 5A and VDSL filter. No need to buy.