Cat5 Problem - Need Help 2

[conceptumator]

Here's a puzzling one for someone with more experience than me:
I have two Cat5 cables in our church network which used to work but suddenly stopped. They are both running through a buried conduit and I can't get them pulled out to replace them. When I test the cables with a simple tester (the kind with a remote on one end that lights in sequence to verify the wiring), they show as being good. When I attempt to connect them to any sort of device (computer, hub, switch, etc.) they will not establish a connection to the network. I have changed the ends, switched jacks, tried multiple switches and hubs, etc., with no luck. The cables are about 5 years old and my have deteriorated, but I don't know how to check that or what problems it would cause. Can anyone please help? Thanks for any suggestions out there.

 

[hbiss]

The cables are about 5 years old and my have deteriorated, but I don't know how to check that or what problems it would cause.

I would say that they are deteriorated because you can't pull them out. Obviously the conduit is filled with water as any underground conduit will. They may check OK continuity wise but the water will cause leakage between the pairs and not allow a signal to pass. A better tester that does a transmission test will show that up.

-Hal

 

[mikeydidit]

It does sound like the cables are in bad shape and need to be replaced. I would use some sort of cable pulling gel or some sort of soap and pour it down both ends of the conduit. You might want to let it set for a day or so before you try to pull them out. Try to get one of them moving. I would try to move it from both ends pulling it back and forth and see if it would break free. If you can get one of them out use the second one to pull in some jet line. Then you can clean this conduit with a rag attached to your jet line and should be ready to pull your new cables in. Use the cable pulling gel on another rag to lubricate the conduit good before you do pull your new cables in. This conduit is apparently a problem area so I would replace these from time to time to avoid this from happening again if possible.

Hope you can get them working..


Mike Jones
Louisiana State University Health Sciences center

 

[conceptumator]

Thanks to everyone. That's about what I figured, I just wasn't sure how to determine if they had deteriorated, but it sounds like that's the issue. We are moving to a new building in 6 months, so I may not worry about it. To make things even better, I think the guy who pulled the original cables used electrical ties to bundle them with serveral other cables in the same conduit - no hope of pulling that mess out.

Thanks again for the input - have a safe holiday.

 

[macphoneguy]

I would concur, the LED testers will not test for things like shorts to Ground Depending on what your running through the cables your best bet is replacing the cabling using the methods mentioned, that being said a standard ohm meter would be able to check for shorts to Ground "usually" that being said if you can get 2 pairs clean, you should be able to get ethernet back as they just use pins 1,2,3 & 6 however if you areneeding more then that your are SOL

 

[wires]

Any conduit below ground can be assumed to be full of water. There are gel filled cables for use in such conditions.

If you are connecting two buildings together fiber is a better solution due to it's non-conducting nature.

 

[jlshelton]

Can you go wireless, temporarily, using a "cantenna" or other directional antenna to get the range you need? Clearly not ideal, but low-cost for the short time.

Also, as macphoneguy suggested, you could use different pairs, if perhaps only some of the pairs are damaged. Get a $10 Ethernet switch for the remote end, so you only need ONE ethernet link. Then, from among the 8 total pairs of wire, perhaps you can find 2 pairs. If you can't tell the difference with your VOM (and you have proven no shorts to ground), then try 1 pair from each of the cables, to minimize the interference between the transmit and receive directions.

Finally, you don't say if you are running 10mbit or 100mbit. If you are running 100mbit ethernet, and you have the option to configure the equipment for lower-speed 10mbit, you may be able to get the signal through.

Post-finally, wires is very right - never connect buildings together with copper. Especially where there are electrical storms. It is easy for "ground" to be at different electrical potentials between two buildings, and for seemingly innocuous network cables to have very high voltages imposed upon them. It's easy to ruin equipment, and possible to damage people, under the right conditions. Yes, the phone company gets away with running copper all over town. But they have strong rules about lightning protection, and still advise you to hang up the phone during a storm. Professional phone installers use "Out of Building" protectors to run wires to phones out of the building. Your computer/network equipment should be as well protected, or, better, run with fiber links.