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Layback Bear
How dose lightning go through a phone line and get to you computer
with out melting the little wires in the phone line like a fuse link?
Animal
It's not the phone line, it's backfeed on the electrical outlet. And it's so sudden if it does act like a fuse the damage is done.
ddeerrff
I certainly can be the phone line. But as Animal said, lightning creats a very fast impulse that gets through fuse-type protection before the fuse has a chance to act. Surge suppressors have fast acting shunt elements that turn on quickly and shunt the electrical impulse to ground.
Animal
ddeerrff, is quite correct, it can be a phone line as well. But usually when lightning damage is done to a computer. More often than not it is traced to the electrical connection pathway. This can be attributed to the fact that "power" is placed the highest of all the utilities, on poles and attachments to homes. But yes, both pathways can be a conduit for lightning damage.
JohnWho
I agree, Animal, but it gets worse:

I've seen PC lightning damage that could only be attributed to the network cable and I've also seen where we were centain it went in through the older parallel and serial ports.

While I don't have any first hand experience with it, I wouldn't be surprised if it couldn't enter through a USB port, too.
BlackSpyder
Ive had it come in though the phone lines a few times. It's always just shorted out the modem. i went through 5 modems in a summer because of errant lightening strikes.

Note none of these where direct hits to the line or the PC just surge voltage (+6volts to +10 volts my guess)
ddeerrff
Back in the good ol' days, when a v.34 modem was considered High Speed, damage from lightning induced voltages on the phone line were not uncommon. Voltage spikes ofv 1000 volts or more are not uncommon on a phone line during a storm. Usually, these spikes are of short enough duration that the modem's built in surge suppression is sufficient - but not always.

Best way to safeguard your computer during a lighning storm? Unplug it from the power lines, and also disconnect the phone line and any network interconnects.
dc3
A good UPS will also protect you from most surges short of a direct lighting strike.
Layback Bear
I thank you all for your quick responses. How that much power, (lightning) can make it all the way down that phone wire to my surge protectors has still got me scratching my little brain. I have a friend who had lightning come down the phone line, melt his surge protector,cooked his computer and then went through the wall and hit his cast iron bath tub.The insurance company sent inspectors to his home to verify the claim before they would pay. I'm still confused.
cowsgonemadd3
Here is a question can it come through a DSL line to fry a dsl modem?
BlackSpyder
yep, CGM3. DSL uses the same utility lines as your phone.
cowsgonemadd3
Oh man that means I still have to unplug something in a storm, I thought I was immune now with my fancy high speed box.
garmanma
We had a bad storm while I was in the hospital and my UPS battery was dead. Luckily the only thing that got smoked was my Linux hard drive
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