When A chopped through B's phone wires...

Two of us are in slight contention over possible damage to a computer.
We are hoping that the collective brains of this group might resolve
the issue. Both of us have agreed this text. One of us is A. and lives
in the same building as B, the owner of the computer. At issue is:

What is the probability that by his actions A caused the damage
described to B's computer.

WHAT A. DID. A number of wires passed through a conservatory roof
where A lives. These were mainly phone cables but also two TV aerial
cables. Most of the phone wires went into a junction box then out of
the junction box and back out through the roof. One of the points
where the wires passed through the roof allowed rainwater to leak into
the building. Knowing some of the wires to be redundant and believing
them all to be so A. cut through them all and pulled them all back
outside the roof. The two holes were then sealed.

WHAT B. DID. On the same morning that A. did the above, B. tried to
make a phone call but was unable and reported a fault to the phone
engineer. On further investigatation B. discovered his phone wires
were cut. "Gosh!" thought B. B. met A. and enquired after the state of
A's phone, whereupon A. explained what he had done. "Oh dear!" they
both said.

WHAT A. AND B. THEN DID. They agreed that, between the two of them,
they might manage to re-establish B's connection by trial and error.
From among the tangle of chopped wires they believed they might be
able to reverse the vasectomy. At first attempt they got a dialling
tone, albeit with some background noise. At this point they believed
they had basically solved the problem, even though B was still unable
to make or receive a calls.

WHAT B. THEN DID. B. decided to test his internet connection. B.
connected his modem to his pc and booted up in the usual manner.
Boot-up went as normal, and everything appeared OK. However, when B.
tried to go online [AOL broadband] it appeared that there was no
connection. B. thought no more of the matter and pottered about for
about an hour. On returning to his pc the screen was all white with
grey vertical bands and some red stripes.

Next day an engineer put the matter right. What A and B had in fact
done was reconnect to the wrong line. However, even with the now
properly restored phone connection B's pc still had the weird grey
with red stripes display. Seeking advice among friends the view seemed
to be a knackered video card. One person suggested that if the
incorrect connection had been to an ISDN line, "which carries twice
the voltage of a normal phone line" that could somehow have fried the
video card's brain. A different monitor was tried with the same
result, thus eliminating the monitor as the problem.

THEREFORE: I refer the right honourable members to my initial
question; what is the probability that A damaged B's computer or B's
video card either by a] initially chopping through the wires or b] by
inadvertently connecting them to the wrong ones?

B's pc is a Pentium iv, slot one running on XP. The video card is an
Nvidia GForce 4.

Many thanks for any help and/or advice!

A. and B.

(E-Mail Removed) wrote:
> Two of us are in slight contention over possible damage to a computer.
> We are hoping that the collective brains of this group might resolve
> the issue. Both of us have agreed this text. One of us is A. and lives
> in the same building as B, the owner of the computer. At issue is:
>
<Snip details>
>
> THEREFORE: I refer the right honourable members to my initial
> question; what is the probability that A damaged B's computer or B's
> video card either by a] initially chopping through the wires or b] by
> inadvertently connecting them to the wrong ones?

The phone connection goes to an ADSL modem (perhaps as part of a router).
It goes nowhere near the video card (or the monitor). The failure as
described is IMHO just a coincidence and nothing to do with the described
actions of either A or B.

--
Old Codger
e-mail use reply to field

What matters in politics is not what happens, but what you can make people
believe has happened. [Janet Daley 27/8/2003]

On Sun, 16 Jul 2006 18:40:42 UTC, (E-Mail Removed) wrote:

> Two of us are in slight contention over possible damage to a computer.
> We are hoping that the collective brains of this group might resolve
> the issue. Both of us have agreed this text. One of us is A. and lives
> in the same building as B, the owner of the computer. At issue is:

It may be worth asking this over in uk.telecom too, since it's not
related so much to broadband as the general technicalities of phone
lines.
--
The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
http://www.broadbandbanter.com

(E-Mail Removed) wrote:
> Two of us are in slight contention over possible damage to a computer[...]

Video cards die on a semi-regular basis for a whole variety of reasons.
But unless the phone line was plugged into the video card, I can't see
any reason why damage to the phone line would cause the video card to
run into problems.

xF,

....Nick

<(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...

Snip sad story.

>
> THEREFORE: I refer the right honourable members to my initial
> question; what is the probability that A damaged B's computer or B's
> video card either by a] initially chopping through the wires or b] by
> inadvertently connecting them to the wrong ones?
>
> B's pc is a Pentium iv, slot one running on XP. The video card is an
> Nvidia GForce 4.
>
> Many thanks for any help and/or advice!
>
> A. and B.
>
>
>

There were several voltages that might have been around, and won't
necessarily have done B's computer any good if presented to it, especially
if they came in on the ground side - these are: -

Telephone exchange voltage (-48VDC), but a modem should live through this
Ring - ~90VAC - ibid
ISDN - 96V

but the most likely culprit is that something without a proper earth was
connected to the aerial cables and has floated up to something like 110VAC
(like my hi-fi - I discovered a nice tingle while messing with the aerial
12m up near the edge of the roof!).

Can't price up the particular card you refer to, but Nvidia start below £30,
so offer him £20 without prejudice.

<(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Two of us are in slight contention over possible damage to a computer.
> We are hoping that the collective brains of this group might resolve
> the issue. Both of us have agreed this text. One of us is A. and lives
> in the same building as B, the owner of the computer. At issue is:
[snip]

IMHO, if the voltage on the phone wire was sufficient to cause damage, it
would have caused other damage before reaching, and possibly damaging, the
video card (ie to the modem/router or even possibly the mother board). As
you said the computer initially booted up OK, I cannot visualise how the
video card, and nothing else, was affected.

Retired

(E-Mail Removed) wrote:
> ... Seeking advice among friends the view seemed
> to be a knackered video card. One person suggested that if the
> incorrect connection had been to an ISDN line, "which carries twice
> the voltage of a normal phone line" that could somehow have fried the
> video card's brain.

The probability is negligible.

The on-hook voltage of an analogue line is up to about 70V, ringing
voltage is up to 100V. The line voltage for ISDN is 96V, so it's nowhere
near "twice the voltage" of a normal phone line, and should be well
within the ability of any modem to withstand it.

Even if the modem was zapped with a higher voltage (eg if a mains cable
came into contact with a phone line) it should not pass that voltage to
other PC components.

You have yet to establish whether an ISDN line was involved at all.

Rather more at issue might be whom BT are going to bill for the damage
caused to their lines - A. or B.?

Owain

On Sun, 16 Jul 2006 18:40:42 GMT, (E-Mail Removed) wrote:

<snip>
>
>What is the probability that by his actions A caused the damage
>described to B's computer.
>

Very low to nil, I would say.


<snip>
>
>WHAT B. THEN DID. B. decided to test his internet connection. B.
>connected his modem to his pc and booted up in the usual manner.

This is the important bit.

If the modem is external to the PC, then it would not pass on any odd
voltages to the PC. It will just be passing normal USB or ethernet
(depending on modem type) signals.

Any odd voltages would have fried the modem before they could possibly
have got through to the PC.

It isn't totally unknown for really high voltages (such as caused by a
lightning strike on the line) to pass down the cables, but it seems
extremely unlikely we are talking that sort of level, and it would
have fried more than just the video card if it were.
--
Alex Heney, Global Villager
Not many people realize just how well known I am.
To reply by email, my address is alexATheneyDOTplusDOTcom

Old Codger wrote:
> (E-Mail Removed) wrote:
>> Two of us are in slight contention over possible damage to a
>> computer. We are hoping that the collective brains of this group
>> might resolve the issue. Both of us have agreed this text. One of us
>> is A. and lives in the same building as B, the owner of the
>> computer. At issue is:
>>
> <Snip details>
>>
>> THEREFORE: I refer the right honourable members to my initial
>> question; what is the probability that A damaged B's computer or B's
>> video card either by a] initially chopping through the wires or b] by
>> inadvertently connecting them to the wrong ones?
>
> The phone connection goes to an ADSL modem (perhaps as part of a
> router). It goes nowhere near the video card (or the monitor). The
> failure as described is IMHO just a coincidence and nothing to do
> with the described actions of either A or B.

Additionally, since A and B both agreed to reconnect the phone lines despite
apparently neither A nor B having any knowledge of telecommunications
technology, A can hardly blame B for anything since A was a party to B's
behaviour, so A might as well accept he's been a bit of a silly and take his
computer to somebody who knows how to fix computers, before he breaks
anything else.

Ian

--
www.jaxtrawstudios.com
science fiction comics with shagging in

(E-Mail Removed) wrote:

> Two of us are in slight contention over possible damage to a computer.

< snip >

Are you normally this verbose ?

I judge a post as much by its succinctness as anything. Something your post is
horribly lacking. I gave up after the first 2 paragraphs.

Graham