Done this before and dont get why you have not got a wire on pin 4 on the extension.
No need to take the complete thing off the wall of the master and stuff the paint up as now pulled that off. Why I did in a new build in 2005 as found the same. Main socket in the cupboard went but nothing on lounge and bedrrooms and hall extensions.
BT wire up the incoming master and guessing it is the builders that run in extensions and dont wire up.
Put the back bit of the master on the wall and drop the front off to expose the cover with the fixed plug on it and a socket and back box on the wall.
Using the unused cable wire up as here. Not sure about your missing number 4 , white with orange bands on the extension. Needs putting on. Ignore the ring wire (pin3) as cause problems with inducing noise or picking up and can slow the broadband speed down.
Need pin 2- 4 and 5.
the colour on the web sites colouring is the mostly colour on the drawing is the mostly colour on the wire (cores).
I have a proper tool for this but place the wires over the teeth of the connector and use a pen knife or small kitchen knife to puch wire in the jaws and it cuts through the insulation.
follow diagram, easy.
pulling the front of the master disconnects incoming cable so safe. replace extension the push front part on to master socket and test by ringing up or do a 1471 and get the last number read out. Replace screws , job done.
http://www.wppltd.demon.co.uk/WPP/Wiring/UK_telephon...
dont cut any unused wires like the pin 3 , orange and white bands. leave there so can be used another day. No pin 3 at both ends.
needs the 3 wires connected.
worked for me.
Edited by deleted (Wed 08-Feb-12 21:18:23)