Master telephone socket

[Muttley Mutterson]

Hello,

I tried to replace my existing LJU socket with a openreach master socket 5c m4 and encountered problems.

The wiring instructions noted to use 3 colours where my existing setup only used orange (broadband) and white (telephone). The wiring to the socket includes a black and green wire but they weren't in use.

I wired the socket using the online instructions which resulted in nothing working. I then connected the new socket using the original set up and the landline works but no broadband.

In the end, I reverted to my original set up so I'm looking for advice on how to proceed.

I'm not sure if this is the master socket, I'm in a bungalow built in the 80s.

Image of my LJU

 

[anotherdrew]

I have not been in the UK for a long time, so some of this information might be out of date.

The master socket is what is called the demarcation point. The lines coming to it (from outside) belong to the telephone company. The lines leaving it are your property. The instructions you were following didn't work because they only explain what to do with your wires. The orange/white/black/green wires technically belong to BT and, at least at one time, you were not meant to touch them.

This video should give you more information. Before proceeding, do read the warning at the beginning.

https://www.youtube.com/watch?v=mbzIR0UkasU

 

[13thmonkey]

^ I'm also pretty certain that you don't go inside the master socket. One of the reasons for this is that the power on the master socket comes from the local green box, or the exchange, and shorting wires out could lead to poor consequences.

 

[woody3883]

Don't worry about damaging anything, shorting the wires out won't do any damage. There is 50v DC on the circuit, whilst not pleasant if you get a shock off it, it won't do you any harm.

Green/black wires are only used for a 2nd phone line if needed or if the orange/white go faulty. So as long as the green/black weren't connected then just ignore them.

Just insert the orange and white wires into the holes on the swing arm connector which face the back box. Each wire has to pass through the top hole and bottom hole. Then screw it to the back box and pop the faceplate on. Plug the DSL lead into the left Jack and the phone into the right.

Just for your informstion, the phone doesn't travel down the one wire and the broadband on the other. Both products travel down together and then the DSL filter splits the 2 from one another in simple terms.

Hope this helps.