Telephone extension boxes

rmg1

My OH has just had her phone line activated and the main box works OK.
There is, however, an extension socket in the kitchen that doesn't work (no dialing tone if the same phone is plugged in).

Are there any simple checks that I can do to test if the socket is wired properly before calling an engineer out?

Bogtrotter

Are there other extensions in the house apart from the kitchen?

If so are all the other extensions not working too?

Dave_C_2

The way BT works is that repairs to the line after the exchange and before the master socket are free. Sadly the internal wiring is after the master socket and you will pay a hefty charge.

Assuming no internet is involved it's easy to check.

On the master socket unscrew and remove the bottom half. The bit that can be removed is where the internal wiring to the extension is connected.

There should be wiring to pins 2,3 and 5 (connection to pin 4 is optional)
Make a note of the colours of the wires on each of the pins.
Make sure none are loose.

In the extension socket, the same wires should be connected in the same order to pins 2,3 and 5 (pin 4 optional)
Make sure none are loose.

After that if you don't know how to do continuity checks etc, you have to pay the man.

Dave

rmg1

Bogtrotter - No other extensions that I can find.

Dave - I can check all that tonight. There will (should) be internet on the line as she's had that put on as part of the package deal from Sky. I'll be testing that tomorrow when I wire up the computer/router/etc. Will that make a difference?
I can do continuity testing quite easily if I know what I'm testing for (I assume it's not going to be as simple as checking all the pins are connected together in the right order on both sockets?).

Bogtrotter

If there is no other extensions follow Dave's instructions.

There will (should) be internet on the line as she's had that put on as part of the package deal from Sky. I'll be testing that tomorrow when I wire up the computer/router/etc. Will that make a difference?
I can do continuity testing quite easily if I know what I'm testing for

Do all the tests on the extension wiring with the bottom half of the Master socket off. Short connection 2 and 5 at the master socket and check continuity between pin 2 and 5 at the extension.

The engineers usually connect the Blue/white trace wire to 2 and the White/blue trace wire to 5 which could be different to the extension socket.

If you have to make new connections you ideally need a Krone punchdown tool (maybe £10 from an electrical wholesaler) they may have a cheapo plastic tools for maybe 50p which will be good for a one off job. Failing either of those it is possible to make a connection with a thin screwdriver pushing the wire down alternately on the inside and outside of the connector but its fiddly

Also I would suggest you try disconnecting the wire on pin 3 (usually White/orange trace) at the master and extension socket as most moderns phones do not use it and it can act as an antenna introducing noise into the line which can reduce the speed of your broadband. If your phone won't ring reconnect the wire.

Dave_C_2

I'll go along with Bogtrotter on this, good advice.

Techy stuff:
Cable colours and pairs
The extension wiring is normally 4-core, which is two twisted pairs.
Common colours for pairs are:
Newer cables: (1) blue/white with blue trace and (2)orange/orange with blue trace
OR older cables (1) solid blue/solid orange and (2) solid green/solid brown.
Order and polarity doesn't matter as long as they are kept in pairs.

Pins 2 and 5
Ignore terminals 3 and 4 for the time being.
The telephone (and broadband) signal is connected via a pair to terminals 2 and 5 on each socket. If you don't get continuity try connecting the other pair at each end.
If you are still stuck check that there isn't a break in the cable.
Pin 4
Pin 4 doesn't do anything. On my master socket there is no connection to pin 4.
Pin 3
This makes the phone ring on the extension - some modern phones don't need this anyway.
If you are using ADSL broadband then you probably won't need pin 3 because the ADSL filter usually contains the ringing capacitor.
Disconnecting pin 3 will help broadband performance.

To recap, disconnect from pins 3 and 4 at each end
Make sure that a working pair is connected to 2 and 5
Always use an ADSL filter to connect your phone

Have fun!
Dave

Enterprise_1701C

Just one thing I would like to add - if it turns out an engineer is needed to sort this out, first ring BT, then fall on floor to recover from their quote, then ring a local independant telecoms engineer for a quote which should be substantially cheaper.

rmg1

Thanks folks.

Didn't get a chance to look over the weekend so I'll have a look this week (at some point when 2 year old is asleep and not wandering off with the screwdriver).