Phone problems after thunderstorm

I am trying to help my grandmother with a phone problem. I'm not
entirely sure what's going on (she's very confusing) but some
(possibly all) of the Caller ID displays on her home telephones are
garbled to the point where they're unreadable. I think it happened
after a thunderstorm where the electric went out. The phones work fine
except for the displays. It's on both the cordless and corded phones.

Is it at all possible that the storm would damage only the displays on
the phones but yet the phones still work fine otherwise? I can't be
sure, but I think even the cordless extension sets that aren't even
connected to the phone line have the garbled display. That seems
really strange to me.

I think the displays on at least five phones are damaged.

 

"Mike S."

** You need to go to her house and get the real facts.

** More likely storm water has got into the wiring ( anywhere from the
exchange to the house) and is causing signal loss & noise on the line -
that will screw up caller ID.




...... Phil

 

Try borrowing a known good caller ID phone and take it over to
granny's house. I'd guess it doesn't work, either. Sounds like
something's wrong with her wiring.

But either way, you'll definitely get an answer by trying a known good
phone in the house circuit.

Good luck
Chris

 

That sounds more like a phone company service issue.

the CID service sounds like its not getting properly
translated from the service to your lines. Your phone
in effect is picking noise that is screwing up the
decoding or, the encoding of the CID signal is incorrect
which should be a phone company issue in both cases.



http://webpages.charter.net/jamie_5"

 

On Tue, 2 Sep 2008 08:59:41 +0100, "Electronworks.co.uk"

:what is the audio quality of the phone like?
:If it is crackly, then water might have got into the phone line (they
:sometimes use airtight pipes to run the cables inside). This will mess up
:the caller id signal.
:

Not correct...

The main junction cables between exchanges are usually pressurised (usually dry
air) to prevent water ingress when minor damage like pin holes in the sheath
occur and to generate an alarm to bring the attention of the telco to the fact
that the cable is leaking. Pressurising the cable does NOT have any deleterious
effect on caller id or any other signals travelling along those cables.

Usually, if water ingress takes place on a subscriber pair it will produce quite
loud 50Hz hum (60Hz in the US) and it may even permanently loop the line if bad
enough. It may also reduce the level and s/n ratio of dtmf signalling.

 

"Ross Herbert"

** Due to all the AC supply frequency current flowing about the soil as a
result of the MEN system ?

** Would the fact this signal arrives during the high voltage ringing cycle
make matters worse ?



...... Phil

 

In the US they often toss power and phone lines into the same trench.
That's also how it is at this building.

AFAIK the ID is transmitted between the 1st and 2nd ring, not during the
ring cycle.

 

On Tue, 02 Sep 2008 08:55:28 -0700, Joerg

hil Allison wrote:
:> "Ross Herbert"
:>
:>> The main junction cables between exchanges are usually pressurised
:>> (usually dry
:>> air) to prevent water ingress when minor damage like pin holes in the
:>> sheath
:>> occur and to generate an alarm to bring the attention of the telco to the
:>> fact
:>> that the cable is leaking. Pressurising the cable does NOT have any
:>> deleterious
:>> effect on caller id or any other signals travelling along those cables.
:>>
:>> Usually, if water ingress takes place on a subscriber pair it will produce
:>> quite
:>> loud 50Hz hum (60Hz in the US) and it may even permanently loop the line
:>> if bad
:>> enough.
:>
:>
:> ** Due to all the AC supply frequency current flowing about the soil as a
:> result of the MEN system ?
:>
:
:In the US they often toss power and phone lines into the same trench.
:That's also how it is at this building.
:
:>
:>> It may also reduce the level and s/n ratio of dtmf signalling.
:>
:>
:> ** Would the fact this signal arrives during the high voltage ringing cycle
:> make matters worse ?
:>
:
:AFAIK the ID is transmitted between the 1st and 2nd ring, not during the
:ring cycle.


Here's the official ACIF (Australia) description - it just says CLI info is
transmitted "during" the ringing stage, but that could well be between ring
bursts. The "normal" ring cycle in Australia has a period of 3 sec (0.4 sec ON,
0.2 sec OFF, 0.4 sec ON, 2 sec OFF), and so on.

QUOTE
Transmission of CLI to telephone call recipients (Called Party, B-Party)
When a call reaches the terminating telephone exchange, that is, the exchange to
which the called party's line is connected, the exchange normally checks the
Address Presentation Restriction Indicator.

If the APRI is set to "presentation restricted" the exchange does not (should
not) send the calling party's number down the line to the called party.

If the APRI is set to "presentation allowed", the exchange transmits the calling
party number during the ringing stage of delivery of the call to the called
party (if the called party is subscribed to the CLI Presentation service).

The called party's telephone answering equipment may receive the calling party's
number in various ways including: in the form of information that is displayed
on a telephone or computer screen, or automatically recorded in a database, or
as an audio message, etc.

 

:
:"Ross Herbert"
:
:>
:> The main junction cables between exchanges are usually pressurised
:> (usually dry
:> air) to prevent water ingress when minor damage like pin holes in the
:> sheath
:> occur and to generate an alarm to bring the attention of the telco to the
:> fact
:> that the cable is leaking. Pressurising the cable does NOT have any
:> deleterious
:> effect on caller id or any other signals travelling along those cables.
:>
:> Usually, if water ingress takes place on a subscriber pair it will produce
:> quite
:> loud 50Hz hum (60Hz in the US) and it may even permanently loop the line
:> if bad
:> enough.
:
:
:** Due to all the AC supply frequency current flowing about the soil as a
:result of the MEN system ?

That's what I would imagine to be the reason for 50Hz hum. Moisture ingress into
a cable will effectively connect the cable pairs to earth via a high resistance
as well as producing a shunt resistance across the pairs.

:
:
:> It may also reduce the level and s/n ratio of dtmf signalling.
:
:
:** Would the fact this signal arrives during the high voltage ringing cycle
:make matters worse ?
:

It sure would. Depending upon the ringer in the destination exchange the ringing
voltage can exceed 120V pk-pk. This will break down a high shunt resistance due
to moisture ingress and can even result in ring trip without lifting the B party
handset.

 

"Electronworks.co.uk"

** Water plus copper wires plus DC voltage

= recipe for TROUBLE !



...... Phil