Self-testing Telephone Line

[polygonum]

My mother's phone has developed a habit of deteriorating in quality in the evenings. It seems to get markedly quieter and has an odd "talking from inside a cardboard box" quality. This seems to happen quite often but getting a proper analysis of exactly which days and for how long just ain't going to happen.

Her phone is supplied by the Post Office and it comes in through an old single socket. A microfilter and two-line splitter are fitted.

She has two phones - one wired, one DECT - both seem similarly affected. Both work absolutely fine at every other time. And all the wires have been taken apart and re-assembled more than once without changing the issue - including changing the microfilter and splitter.

She (or someone) has contacted the PO and they seem to have run some tests and declared the line to be fine. I strongly suspect that any tests were run during the day so we agree they'd be likely to be fine - the issue only happens in the evenings.

At the moment, I am hypothesising that the issue is on the line rather than an actual phone.

What DIY testing is possible? Are there any diagnostic numbers available?

It is a fair old drive to get there so the ideal would be something I can explain to her. If it is simple enough she can do the test when the line is bad and, hopefully, identify the issue. But if I need to go over, so be it.

[charles]

worrying - The Post Office haven't supplied phones since 1980!

[Andy Cap]

That'll be BT then, not the PO.

The simple thing to do is get a known good phone, best borrow one and eliminate all the existing equipment, then after disconnecting everything else, plug it into the socket where the line first enters to house. If the line still sounds distorted, insist on an engineer's visit. If you'd done this, they'd be hard pressed to prove it was on your equipment and therefore apply any charge.

Andy C

[Andrew Gabriel]

They have - they provide a separate phone service. I don't know if they use carrier preselect over BT, or LLU. If you asked this question on uk.telecom, you would get people who will know this off the tops of their heads, and likely know if things like 17070 and/or the BT web pages can be used to generate a line test on a Post Office service.

[Dave Plowman (News)]

I'd first check the DC volts across the line. During the day when things are fine - then when the fault is present.

[Mike Tomlinson]

En el artículo , polygonum escribió:

[crossposted to uk.telecom, so quoted in full]

If the first socket on the line (the master socket) is of the type with the removable faceplate, undo the screws and pull away the lower half. This will expose a test socket. Plug a *known good* (preferably not one of hers) working phone into this (without the ADSL splitter and socket doubler) and see if the problem still exists.

If yes, call the phone suplier and report it as a line fault.

17070 works on BT lines. Try the quiet line test.

You say she has a microfilter, so she has broadband. Is that working ok? Has the line sync speed changed?

[Brian Gaff]

Don't know about that but increasingly I've been finding that somewhere on a call its carried in a voip form which degrades when the traffic increases. this sounds like its in a cupboard and has a sever hf cut off and some limiting on the sound.

I am wondering if phone companies are using this approach to help with demand. Brian

[Peter Parry]

There are well known issues with some DECT phones and ADSL but these usually show up as noise on the line. The phone system is simple and fault finding is a matter of being very methodical.

The first test to try when the line appears faulty is simply to unplug the ADSL filter, splitter and DECT phone and her existing phone and plug only a known good simple and wired phone directly into the phone socket on the master box. The simpler the phone the better (Charity shops and the like are often a good source of appropriate phones).

If that solves the problem leave everything disconnected and replace the test phone with her normal phone. See if the problem returns.

If it doesn't, plug everything else back in one at a time testing at each stage.

Is there a Sky box in use?

You might find it useful to make up a simple test sheet for her with a column for the action (such as unplug everything bar the test phone) an a space to record the result.

[Peter Parry]

I'm afraid these days BT often apply the test of "no fault found on our equipment" to justify a callout charge. This would be especially so if when the fitter tested during the day no fault was apparent as seems to be the case here.

[Huge]

We've had years of intermittent faults with successions of visits reported "no fault found". I've never been charged for anything. And wouldn't pay even if we were.

For about three years the broadband and then the phone packed up whenever it rained. By the time the BT wireman (I refuse to call them "engineers") arrived, the fault had always gone away.

One useful thing one of them did tell me was that it is helpful to run a line test yourself when the fault is active, because they can recover the results of that when they visit, even if the fault is not extant.

[Michael Chare]

I would suggest getting the PO to test the line in the evening when the phones are disconnected.

With BT you could request this test either from the phone line itself or from another phone. I presume the same is true of the PO.

I would also suggest trying the line with a known good phone plugged in by itself.

If the PO don't see a fault I doubt that there is much that you can do. Trying to arrange an evening technician visit would be difficult.

[Dave Liquorice]

Why do you state that so categorically, do you know the OPs mother?

The fault is intermittent and in the evenings. The physical local end is probably supplied and maintained by BT Openreach under contract from the PO. If BT Openreach come out and don't find a fault they will charge the PO who will no doubt pass that charge on.

I really can't think of a local end fault that could produce the described effect. The suggestion of an overloaded link and VOIP is a possibilty. It might be possible to force calls via another carrier (via a prefix number) and see if those are similarly affected.

Getting this sort of intermittent thing sorted out can be a real nightmare. Had a noisey line once BT couldn't find it and kept saying "no fault found" until I managed to get a call to faults when the crackles were present...

[polygonum]

Which test is that? Have just tried 17070 on my own phone and when I choose option 3 - test, it asks if I am authorised to run it.

[Andrew Gabriel]

It's buried somewhere on the bt.com web pages.

Some ISP's (such as Andrews&Arnold) also give you access to do it via their control pages, and you can see the full results that way.

[Peter Parry]

For many years BT only ever charged if the subscriber had done something really crass and very few callouts resulted in charges being raised. Since the line and repair element became Openreach and available to other service suppliers than BT that has changed considerably. Especially so in the last 12 months where "no fault found" visits now often generate a charge.

[Huge]

Not in my case.

[newshound]

If she *does* have broadband you could perhaps set up "JDs Auto Speed Tester" or one of the other testers which log ADSL data. Logging say every quarter of an hour for a few days should show up if there is noise which varies as you describe, which gives you physical evidence. You might also chase the ISP if the performance is outside what they claim for your postcode in the advertised link.

[polygonum]

Difficulties in that direction at the moment - not technical ones, human ones.

It has been working excellently.

[Rick Hughes]

does it have a dial on the front ?