Phone doesn't ring

Hi, not broadband but I'm sure someone will be able to be helpful... In short, one of our phones has stopped ringing.

We have; master socket, one extension with a DECT phone, one extension with a corded phone, one extension unused. All used to work. About a year ago we had a light switch moved which involved moving the kitchen phone socket a few inches (corded phone). I'm sure the phone worked ok after that. I recently noticed that the kitchen phone didn't ring on an incoming call. As it's a cheap phone I thought there was probably a problem with it and today I've bought a new one. It doesn't ring either. It, and it's previously suspected dead friend, both ring ok if plugged into the master socket or the extension normally used by the DECT phone. I've discovered that the unused socket doesn't ring either, so that rules out a faceplate problem (probably). Both phones give a dial tone and work, other than ringing, in the two faulty sockets That's the bit that's puzzling me.

Any suggestions?

If you put a microfilter between the handset and the not working sockets do the phones ring then?

In reply to a post by JHo1:

Hi, not broadband but I'm sure someone will be able to be helpful... In short, one of our phones has stopped ringing.

We have; master socket, one extension with a DECT phone, one extension with a corded phone, one extension unused. All used to work. About a year ago we had a light switch moved which involved moving the kitchen phone socket a few inches (corded phone). I'm sure the phone worked ok after that. I recently noticed that the kitchen phone didn't ring on an incoming call. As it's a cheap phone I thought there was probably a problem with it and today I've bought a new one. It doesn't ring either. It, and it's previously suspected dead friend, both ring ok if plugged into the master socket or the extension normally used by the DECT phone. I've discovered that the unused socket doesn't ring either, so that rules out a faceplate problem (probably). Both phones give a dial tone and work, other than ringing, in the two faulty sockets That's the bit that's puzzling me.

Any suggestions?

Internal phone wiring uses three wires, the two signal wires, A & B, plus the ring wire. The phones have their ringer circuit connected to this.
If the ring wire is disconnected somewhere between the master socket and the extension then the phone will work but not ring.
Alternatively the A and B wires to the extension may be swapped.
Ring current flows between the ring and A wire so if A and B are swapped - no current flows.

The ring signal wire is derived at the master socket. Do you know how the extension wiring is arranged (i.e. star, daisy chain etc).

The reason for the ring wire is to prevent 'bell tinkle' when other phones are picked up and put down. (and also on dialling on old rotary phones).

Edited by Eeeps (Sat 21-Feb-15 13:50:04)

I have found;

"Many years ago the UK telephone system adopted a different policy to that in the rest of the world. Here in the UK we made a choice to move a component called �the ring capacitor�, which enables the telephone to ring, out of the telephone and into the socket on your wall. It was a good idea at the time because it made it possible to stop the �tinkling� that occurred on other extensions when an old rotary-dial telephone dialled a number.

However, there was a downside: To get the ring signal into the telephone we now
have to run a third wire from the socket to the phone. Also, since we only need one
ring capacitor on our line, and it is located at the 'master' socket, we have to take
three wires to all our extensions, rather than the two wires which come to the house.
On most modern wiring you will find the original phone signal connected on the 'bluewhite' pair of wires and the extra 'ring' signal connected on an orange wire, though this convention is not universal.

Now, since ADSL filters only filter the main telephone pair, they must re-generate the ring signal themselves. All of this is of only passing interest but it does mean that you only need to feed an ADSL filter with two wires. The ring signal for the third pin on the attached phone is generated internally."

on http://www.solwise.co.uk/downloads/files/adsl-around...

I'd like to see "many years ago" quantified. The reference to dial phones suggests the 1960s, i.e 50 years ago. It was certainly my understanding that the ring wire is no longer required but maybe as we move from ADSL to FTTC we need to unlearn the "disconnect the bell wire, it acts as an aerial and introduces noise" mantra?. But if that was true then everyone who has ever disconnected their bell wire, and that must be tens of thousands (?) would be suffering this problem?

I'm doing nowt until I get some more advice!

Thanks,
John

Hence the asking if the phones ring when connected via a microfilter - which reproduce the ring wire.

Many modern phones do this internally for themselves too.

This is what I have to do with some old phones now I have fitted a Mk3 faceplate on my master socket because that does away with the 'Ring' wire !

Edited by APTMAN (Sat 21-Feb-15 18:33:22)

In reply to a post by JHo1:

I'd like to see "many years ago" quantified. The reference to dial phones suggests the 1960s, i.e 50 years ago. It was certainly my understanding that the ring wire is no longer required but maybe as we move from ADSL to FTTC we need to unlearn the "disconnect the bell wire, it acts as an aerial and introduces noise" mantra?. But if that was true then everyone who has ever disconnected their bell wire, and that must be tens of thousands (?) would be suffering this problem?

When I started work in 1980, dial pulse was still around. In fact this was in the form of a of a hybrid - a push button phone that produced pulses rather than DTMF.

The bit of the explanation as to how the ring wire worked is missing from this. The phone that was doing the dialling actually shorted the ring wire to the A wire.

It is true that these days telephone ringers can filter out other pulses on the line and only react to the 25Hz ring signal. This means they can use the A and B wires directly. This is why many people who disconnect the ring wire don't have problems.

On the subject of the ring wire and DSL signals. The wire also acts as an impedance imbalance between the A and B wires. This causes common mode noise to be induced on to the A wire in preference to the B wire (particularly at high frequencies). This imbalance impacts the whole line from the DSLAM not just the internal wiring. (i.e the differential 'pickup' from noise and crosstalk occurs on the full length of the cable).

In reply to a post by APTMAN:

This is what I have to do with some old phones now I have fitted a Mk3 faceplate on my master socket because that does away with the 'Ring' wire !

No it doesn't.

Probably better expressed as removing the influence of the ring wire at xDSL frequencies.

I read his post as saying now he has the Mk3 faceplate phones that used to ring at extensions don't any more. That may be true, but not because of the new faceplate per se.