Phone problem question - fried wires

Old 07-15-03, 10:20 AM
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Phone problem question - fried wires

Wanted to get other people's opinions on what might be the root problem here.

I've been at my house now for over 2 years, and been using the intercoms mentioned for about 8 months. I've never had any phone issues other than cutting the line once putting in 4" edging.

Last Monday morning the intercoms (old wired kind that piggyback on the phone line) starting making random noise. Later that night I noticed heavy static on the phone line. Unplugged the intercom and the static was still there.

The next day I come home and the line is pretty much dead at all phones, although occasional when I pick up I'd get a busy signal. The line was fine at the box outside, however. I took a voltmeter to all the jacks, found one that was only ready 2V causing all the rest to drop to 12V. I switched from the blue pair to the orange pair on that office line at both ends, everything went back to ~48V and was fine.

Late that same night the intercoms starting squealing again, so I unplugged them both. Before that though I set the voltmeter on the kitchen line to see if anything was amiss. While it was in the acceptable range, it fluctuated a lot. Normally when I measure you know it bounces between a few values, but this was all over the place (45-49V).

Again when I come home the next day the lines were dead, this time hardly registering at all (.6V). So I unplugged the orange pair at the box and everything works.

The wires that keep going bad are on a line run on the side of the house up to the 2nd story. Visually it looks okay, but if it's shorting out or something I'm not sure what would have caused it.

I just switched to an alternate local phone service provider (my employer) 3 weeks ago. Because they are leasing the line am I talking to ALL the same equipment as before? Or would some of the equipment at the CO be different?

I think it's something with interference on the line due to the new phone provider, but could it be this outside line? I'm sure the intercoms are just reacting to line noise and are not the culprit. Anyone have any other tests I can run on the wires to see what's going on? I could switch to green or brown but I don't want those to 'fry' as well and be left with just one pair or have to run a whole new line.

Also worth noting, the cable company is coming out today because my cable modem (tv signal ok) has been off/on for several weeks now. The lines coming to the house are close to each other and probably cross at some point.
Old 07-23-03, 07:50 AM
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Guess you have your answer by now, if the cable company came out there.
The cable company uses higher voltage and if wires were crossed that is what burned up your wires when you supplyed the ground each time you swiched wires.
Old 07-23-03, 07:57 AM
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The cable company's work didn't change anything. The lines cross before the boxes, where the phone works fine, and they should be well shielded. The line having the problem runs on the outside of the house up to the 2nd story.

Since the voltage never 'spiked' or went too high on the phone, could it have been a surge in current that fried the wires in one particular line?

I haven't had time to try a 3rd pair of wires on the phone yet to see if the same thing happens.
Old 07-28-03, 07:57 PM
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Wink ohmsmeter

volts are only half the picture check for shorts/ground going inside on your pair. chase trouble till u find it . make sure to open service outside and remove volts before reading.
Old 07-28-03, 09:22 PM
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The line was okay at the box, but somewhere along the outside of the house it was shorting on 2 of the pairs. He couldn't explain it, and even after tearing it down there was no visible place that was obvious. We put a new Cat5e line up (old was Cat3) and it's fine so far.

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