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A weird problem with the phone line
opus
jc
Today while I was chasing up a delivery by phone, the call was disconnected. Since then, the phone line here has been exhibiting extremely odd behaviour and is intermittently dying. Currently, it's unusable.

No phone sockets have been touched at all in the past few weeks, so the problem seems spontaneous. I started to realise problems may be happening when the old bakelite kitchen phone, which normally goes ping every time it receives a burst of data such as Caller ID info, started to ping randomly over a period of a few hours. When I picked up the bookroom phone, I heard a really loud and disturbing noise interfering with the dialtone, much like a low-powered buzz-saw. I experienced the same problem with my phone, but not with the kitchen phone. I unplugged the kitchen phone.

Now, nothing except plugging the kitchen phone back in would cause the line to hang up. In the UK, when a phone handset isn't replaced after the end of a call, a few minutes of silence are followed by an ear-piercing wailing alarm, which does Not Go Away until somebody notices and replaces the handset. For all I know, this could have been happening for hours, as none of the handsets were emitting this alarm until, after a while, I almost had a heart attack when I picked up the bookroom phone again.

When I finally managed to obtain a recognisable dialtone on my own phone I called BT's automated fault reporting service. I was asked to hang up while the tests were performed; I have no idea whether the line actually hung up once I put the phone back on the hook, but once I managed to get a dialtone again I was informed that a fault had indeed been detected between the exchange and my property.

I was invited to input an alternative number (my mobile number) in case engineers needed to contact me. I was given the option to receive updates of the situation by text message, which I decided to accept. Then I was again asked for an alternative number (my mobile number), which in this case would have incoming calls forwarded to it free of charge while the matter was resolved.

Best of all, I was informed that if the problem was not corrected by 5pm tomorrow, BT would refund the next month's £8.50 line rental, and credit me £1 per day towards additional mobile call costs incurred as a result of my loss of service. I'm almost hoping the problem isn't fixed before then, since I don't really lose much.

The only reason I could write this entry is that my ADSL connection, which relies on the same phone line, remains uninterrupted. I tried turning off the modem temporarily, as that had been part of the problem back when I discovered my DSL microfilters were useless, but that did nothing to resolve the buzz-saw problem. When I turned the modem back on, it re-synchronised with the exchange within seconds. I'm surfing as if nothing had happened.

How incredibly odd.

Update 16:55: Just had a phone call on my mobile from a nice BT lady who just confirmed various details with me, and told me that while engineers hope to have the problem resolved ASAP I've been given an estimated time of repair of Monday. Yay?

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IANATE (I Am Not A Telephone Engineer) BIUTPABOAW (But I Used To Play At Being One At Work):

Sounds a bit like an automated line test gone wrong. The automated line test checks for the 1.8μF capacitor in the master socket. If it somehow blew this, or blew the circuitry in the DSL filter, it is possible that equipment connected through the microfilter would function correctly. Very old telephones had this capacitor built in.

Suppose the line test starts, and it blows the capacitor in the master socket in a messy way (such that it now is a crap capacitor and has good conductance, or more likely is insulating and not capacitive). Now, suppose also that the exchange is rather stupid (poss System X not AXE10) and doesn't stop trying to test the line until it detects a capacitor, or that it keeps checking in case it's a temporary fault. Then, when you plug back in your old phone, complete with capacitor, hey presto, it all works again. DSL not affected because its signals are designed to cope with a noisy network, and get spliced off at each end.

If this is the case, the cocked-up capacitance at your end might fool the automated line test facility (aka reflectometry test) into thinking the fault was closer to the exchange than it was. Did you try, when it seemed to be behaving itself, plugging only one, relatively recent, telephone into the master "BT Only Beyond This Point" faceplate. Usually this is behind your own faceplate - this is to allow easy consumer installation of extensions. Do that, and try a 17070 ringback (this requires a touchtone phone - key 1 at the menu IIRC).

See what happens. Anyway, IANATE again and good luck!

I only mentioned the microfilter problem I had last year to justify my reasoning behind turning off the router. I can't say I'm convinced that this has anything to do with the microfilters.

What happened with the kitchen phone was weird, as unplugging it generally had no effect on the buzz-saw noise I heard on the two remaining phones. With the kitchen phone unplugged, neither of the remaining phones had any luck affecting the hook status.

One test I tried with my own phone involved repeatedly picking up and hanging up while listening to the ringing sounds emanated by the plugged-in kitchen phone. Normally, when the phone is picked up the kitchen phone emits a ping, and hanging up causes the kitchen phone to emit a lower, longer ping. This time, the kitchen phones were emitting the tones in the wrong order, giving me the impression that picking up my phone hung up the line (I heard silence from the phone itself) and hanging up resulted in a pick-up.

The cycle goes from normal dialtone, to buzz-saw, to silence, to piercing alarm until I can actually manage to hang up. I had established this before I first dialled 151, and have had three successful dial-outs during this mess.

Currently, the setup as it comes into the house goes through a doubler in the bathroom. The "master socket" runs off this and lives in the bookroom, from which my own phone and DSL modem run. The other socket that runs off this doubler lives in the kitchen. When I had the last problem back in October, the BT person had the nerve to ask me to hack around in my own sockets, insisting this was an issue with the sockets themselves when the problem lay in the microfilters. I'm not willing to do that this time round.

I was suggesting that it was unlikely to be something to do with the microfilter, in my first comment.

I'm now confused, though: How can your master socket run off a doubler? The master socket is a single socket, which is usually big, has a horizontal line across it and beyond which no mere mortal is allowed to fiddle. If it really is the master socket and the doubler wiring is BT-owned, there can only be three reasons that I can think of:
  1. Is the doubler just an ordinary doubler or is it a DACS? This unlikely, because I have my doubts that a DACS would work with DSL
  2. Or, perhaps you have two 'proper' telephone lines (not DACsed) and the "doubler" deals with the different pairs
  3. Or, finally, the doubler is used to take a telephone line to someone in another flat in your block...


Or, you, like us, have a telephone setup that defies explanation! We have three lines associated to four numbers (two POTS and two MSN DDIs on ISDN2e), and somehow we end up with three master sockets. I hope I haven't confused you too much.

Does the image on the right make things any clearer?

The line you see coming in from the top runs along the bathroom wall to another similar-sized box near the window, which doesn't look at all like a master socket but is the first thing the phone line sees when it enters the house.

One of the two lines out the bottom leads to the kitchen phone socket, which doesn't look like a master socket either, and the other runs to the other end of the house and into the bookroom, where a socket that does look like a master socket can be found.

Note the ghetto BT logo on the bottom left hand corner of the faceplate. I'm keeping that faceplate if it's ever replaced.

Lol, ahh, hmm. Ok, it's not a DACS, and I think I'm starting to understand. One good thing to ask your friendly local BT engineer is up to what point do BT own the wiring. You may find their ownership stops at the box shown in the photo. In which case, you may find a neat rewiring of the contents of that box might help, would certainly do no harm, and might save you from a lot of money.

For that, all you would need is a krone tool and one of those wee boxes (the boxes still make it like that, sans Thatcherite BT logo). Dead easy to put in.

Also, I take it you don't have two seperate phone numbers, then? It's not easy to tell if two seperate pairs are getting taken off the drop line in the picture.

The reason the kitchen phone socket doesn't look master is that the master-ness is built into the old phone.

My hypothesis is now that one of several things is up:
  • It's beyond this junction box (exchangewards) and therefore definitely BT's business (possible).
  • It's an old connection in this junction box that has (somehow, and it does happen!) worked itself loose and may or may not be BT's business depending on where ownership changes. Try replacing it.
  • It's on the wiring to one of your phone extensions (unlikely).
  • Your old phone is b0rked :/ - quite probable. To check, you could try either putting a master socket on there as well (temporarily, and again dead simple to install w/krone tool) and use a normal phone on it, or, disconnect the line to the kitchen carefully at the box shown in the picture (remembering to put it back ready to do the 'who me' act to the BT engineer).
  • The fault is with 'modern' kit (also quite unlikely)
As usual just my dha sgillinn, and IANATE :). Good luck!


and stuff like that.

Remember kids, ths information at the above links is for entertainment only. Nil by mouth, cabin doors to manual. This train doesn't stop at Inverkeithing. :P

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