Telephone Fault

[kajr]

Does anybody know what might be causing the following fault. Phoned the wife at home from work yesterday and the line was terrible. When I got home I checked my emails. The broadband connected ok but the dial up wouldn't as there was no dialing tone. BT checked the line but said that there was nothing wrong their end and suggested the connection at my end was faulty. As far as I can see the connection in the main box is ok. Also I don't follow this as the broadband is working. When phoning my number I get engaged. There is a connection in the incoming line via a terminal block joining two cables under the eaves of the house. BT are coming to look but was just wondering what the problem could be. Kevin

[Set Square]

If you've got a standard NTE5 master socket, remove the faceplate and plug a phone directly into the test socket inside (not through a filter).

If this works, the problem is in your internal/extension wiring/micro-filters etc. - and BT will charge for sorting it. If it doesn't work, the problem is between you and the exchange - and it is BT's responsibility to sort it out.

It is not unknown for ADSL to continue to work even though there's a duff joint somewhere which stops phones from working.

[Lobster]

I should ask on uk.telecom if I were you: the fault is clearly playing merry hell with your newsreader

[Andy]

For the number to be engaged there is probably a short circuit between the A and B wires of the telephone line, or an earth on the B wire, the DC resistance of which is low enough for the exchange to see it as being off hook. (It could also be a fault in the exchange itself.) This could be your side of the NTE5 master socket (if you have one) or BT's side. Do what Set Square suggests to try and localise it.

Look out for any wet junction boxes that could be causing a short or an earth or both. Squashed cables is another thing to look for. Look in any screw terminal boxes to check that there are no loose wire (causing the initial bad line) which has now become a short.

As BT have tested the line (hmmm?) they should be able to see an earth that is big enough (or I guess that should be "low" enough - BT had, or certainly used to have "big fat earths") to cause this problem. If it is a short it may be just low enough to cause an off hook condition but also be close to you house so that BT see a normal capacitance when testing the line.

The box under the eaves is almost certainly BT's responsibility and if it isn't a water proof connection it could well be causing the fault. If it is this try to get them to run a new drop wire in one length from the pole to the NTE5 rtaher than just "fix" the fault.

The ADSL works at high frequencies so can "pass through" a fault that will not pass the DC that makes your telephone work. Hence ADSL working but not voice.

Andy

[Mike Barnes]

Too true. Our phone was completely dead for a period of six days last year, due to a BT fault, but the ADSL worked perfectly throughout.

We missed the phone a lot less that we'd have missed the ADSL.

[Colin Wilson]

Check on google for similar posts in uk.telecom.broadband - I think it may be something to do with a high resistance fault, but can`t remember for sure.

Broadband has been known to work where the phone is otherwise knackered.

[kajr]

Well BT have just been and apparently it was a faulty ADSL filter. When I get home I will try swapping filters around to see if it just the one which I guess it is.

Kevin

[Set Square]

In that case, it will cost you dear for having them come to fix it.

It really does pay to do your own basic diagnostics first, before sending for BT - especially when you post in uk.d-i-y!

[Andy]

You say "apparently" it was a faulty ADSL filter. I assume that you were not in when the BT engineer was there. If it was the filter that was faulty, which it could be, you should be able to reproduce the fault. If you cannot and all of the filters work okay then IF BT charge you for the call out you should dispute the charge. Certain faults can clear themselves or be fixed by another engineer doing work elsewhere. The BT engineer may try and point the fault at your equipment rather than theirs.

Of course if a filter is faulty then you could have found this out yourself before calling BT ;-)

Andy

[Dave Stanton]

Braodband extends up to RF frequencies so will work where simple voice wont. Can even work on only one leg of the line.

Dave

[kajr]

I have now checked all the filters and one of them recreates the fault. A pity BT didn't suggest that to me in the first place.

Kevin