WTF? Can network cables go bad?

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I have a home network which consists of a comcast cable modem hooked up
to a belkin router which then has cables running to a desktop running
XP and a wireless transmitter that my laptop uses to access the net.

Everything was fine until a couple of months ago when the comcast
internet hookup went out.  When it came back the netowrk didn't work
anymore.  I spent some time trying all manner of fixes (pwer cycling
everything in the right order, switiching the cables around etc.)
nothing was working, than one day I woke up and the network worked

Well this has happened again, almost exact same scenario, only the
network isn't coming back.  I've tried releasing and renewing the IP
adresses, used a differnet router, checked the belkin router with a
couple of short cables (it worked fine) and a few other things.  The
cables running from the modem to the router and from the router to the
desktop cover about 60 feet each and are run through my attic and into
my garage.  This setup worked fine for 2 years and now suddenly it's
FUBAR.  So what can it be?  I've noticed that the router recognized one
cable but not the other.  That's about the only way I have of cheking
it, since when the "good" cable is run from the router to the modem I
still can't use the laptop on the internet since the host computer
(desktop) isn't showing up.  And of course when the "good" cable is run
from the desktop, the router sees it but I have no internet connection.
 So it sure seems like the one cable has gone bad, but I really don't
want to run (and make) a new cable and I don't know how a cable can
just go bad, unless it's being pinched somewhere I don't know of, but
wouldn't that have caused a problem long ago?

If anyone knows of other possible causes of this problem I sure would
appreciate you letting me know before I run the new cable.  Also if it
is the cable, is it possible when comcast was fixing the internet they
did something (they fixed the problem "upline" as they say) they sent a
power surge or sumthin' that fried the one cable??  What else can cause
a cable to suddenly go bad?

Re: WTF? Can network cables go bad? wrote:
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I have had a cable inexplicably go bad.

Re: WTF? Can network cables go bad?

On 25 Apr 2006 19:33:35 -0700, wrote:

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At that point the key is pinpointing the failure point.
Load up the router config screen (HTTP access usually), and
the modem too.  Reboot both if necessary.  

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Did the network link lights on the router's switch indicate
a good connection?  At that point the ideal would have been
to ping systems, ping the same system you're on from itself,
ping the others, use the CMD line to "IPCONFIG /ALL" to see
if it's picked up the DHCP parameters (assuming you hadn't
manually configured them).  Ping the router as well, and an
IP on the internet, and a "tracert" at the command prompt to
a domain name like

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The key is to check the connections with the software tools,
then when you identify where the logical connection is
failing, investigate the hardware at both ends of this
failure and the cable inbetween.  Cables can go bad, or the
connections are just dirty and unplugging/replugging same
cable a few times (if not taking a cotton swab and cleaning
the contacts) might help.

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A surge can blow a network port.  Swap the cable to another
port and retry it.  Isolating exactly where the connection
is failing logically with the software/OS is the first step

Re: WTF? Can network cables go bad?

Instead of running a new cable, first, recrimp the one you've got and if
that doesn't help, try cutting off the connectors  and put on new
connectors at each end.  It could be a wire in the cable is broken but
it's much more likely that one connector or the other is now defective. wrote:
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Re: WTF? Can network cables go bad? wrote:

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Is it possible that a mouse could have eaten and partly damaged your
cable?  You said that the cables run through an attic and garage, and
that could be possible if you have mice in your neighborhood.

You could get a coupler and connect another cable to the one you think
is bad and pull it through the attic/garage.  Examine the original
-bad- cable for damage.

Unless the cable has been stressed, I wouldn't think that it would
just "go bad".


Re: WTF? Can network cables go bad?

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Cables that "go bad" usually do so at the end connectors.
It's recommended by cablers that cables running in the
wall or in raceways between stationary outlets be solid
wire, but that cables running to movable equipment - like
routers, modems, PCs - have stranded wire for flexibility.
Problems arise, though because the plugs are specific
to the two types of wire.  A plug made for solid wire cuts
the strands of stranded wire, and plugs made for stranded
wire don't make good contact with solid wire.  There is
also the fatigue factor with manually crimping plugs onto
cables, and for consistency in crimping pressure, pros
just go with factory-terminated jumper cable for the flexible
cables.  Since factory-terminated jumper cables are cheap,
why not go with those and leave the solid wire cables in the
wall and attic and have a couple less things to worry about?


Re: WTF? Can network cables go bad? wrote:
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Yes, like many have mentioned, cables can and sometimes do go bad.
The problems can range from a simple bad crimp on a connector to nails used
to hang pictures on a wall.

I always suggest people who want to work on their own systems go ahead and
get an Ethernet cable tester.
Here is a link for the model that I purchased, actually I bought a couple of

I keep one in my tool kit that I take to locations and one stays at home so
I don't have to look for the other one. ;)
I had no problems with customs or anyone else when I ordered them but then
possibly I got lucky ;).  At these prices it was worth it for me to try
ordering direct from the source.  I used PayPal but you could also use one
of those one-time credit card numbers that many Visa or MasterCard venders
offer if you are worried about giving out your numbers to an overseas

The testers have been one of my best purchases when it comes to
troubleshooting cables.  I like the fact that the tester is actually in two
parts, one for each end of the cable.   Makes it much easier to troubleshoot
a cable that is already in a wall or conduit and when each end of the cable
is in another part of the building.  If both ends of the cable are in your
hands the testers two parts simply slide together turning them into a single
hand held cable testing machine.

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