Solved! Go to Solution.
Welcome to this user forum.
Then that would indicate an issue with your internal wiring, perhaps the builders have installed it incorrectly?
Do you have FTTP (Fibre To The Premises), with a box on the wall which looks like this?
Builders electrician has check wiring and all ok.
We have fibre broadband and line which works fine as long as it’s connected to the master BT socket 5c.
So its not FTTP as I asked.
You have an internal wiring issue which is your responsibility. Its possible the extensions have never been connected.
The wiring to the extensions should be connected to the connection block behind the front removable section of the master socket, as shown here in blue or clear (ignore the arrow)
Noting was connected inside the master socket. The blue part (clear on ours) has not wires going into it.
Then that is why your extension sockets are not working. You will have to either ask the builders to connect the extension wiring to that terminal block, or connect it up yourself.
Only two wires are actually needed to be connected. They may be marked 2 and 5 on the extension sockets. You should find the extension wiring that the builders fitted, nearby.
Openreach only provide the connection from the line, to the master socket, the rest is the customer`s responsibility.
If you look inside an extension socket and see what colours are connected to pins 2 and 5, then that is the pair you need to connect to the connection block on the NTE.