Just finished wiring the garage to the house - and find that the wire is damaged! Now what?
I mean, the simplest answer is to lay a new cable, and that is definitely what I am going to do - that's not my question.
But this is a long run, and it would be neat if I could salvage some of that cable. How can I discover where the cable is damaged?
One stupid solution would be to halve the cable and crimp each end, and then test each new cable. Repeat iteratively. I would end up with a few broken cables and a bunch of tested cables, but they might be short.
How do the pro's do this? (Short of throwing the whole thing away!)
My TP link switch can detect faults and cable length. I’m not sure it can do both together but it’s possible. Worth checking if you have a switch with those features
you can rent a time domain reflectometer for this purpose.. it sends out a signal and then listens for the echos back and calculates the distance. problem is they arent accurate the first like 500 feet so you have to add a reel of 500 ft of matching cable to the end first. electrorent.com rents them.
I had an AMD Phenom-II era motherboard that claimed it would be able to do that. OP, you might be able to find an old NIC/mobo that could do this for cheap.
Actual, not academic. And I agree that a new cable is cheap, which is what I will do. My question is about avoiding throwing a mostly good cable in the trash.
If you just want some spare cable. I'd make 5x 20M pieces. The one that doesn't work becomes 2x 10M. That bad one becomes 2x 5M ... As far down as you like.
Isn't that almost what they suggested except starting at a different size and doing a binary search basically? You're just starting the binary search after the first step of cutting into 5 lengths instead of 2.
Yeah, that's not that easy, unfortunately, because each end of the network cable passes through an insulated wall, through a hole equal to the cable width = smaller than the plug. Even if I find the break, it is likely in the outdoors part of the cable where I would want an unbroken cable without a field repair.
How do you know the cable is damaged? If you have a toner you can hook the generator to the damaged pair and listen along the length of the cable to where the tone changes. It's not as fool-proof as a tester, but much cheaper.
I assume the disco fever is all the pairs shorted together. Is this cable buried or run through the house? I would start by redoing your ends. Make sure they are crimped fully and both sides are identical.
short between pairs probably.
tdr (time domain reflectometer) cable tester should help locate fault. might be pinched somewhere or something else
there are "casts" you can get to repair buried cable. usually used in copper telephone plant, i wouldn't trust it to certify to a gig but you could use it for a backup link or if you play with pots at some point. or "temporary repair"
Can't you just use a cheap non-contact voltage tester to find where the cable is damaged? Just run the tester through the cable until it suddenly stop detecting any AC voltage, which is probably where the cable is broken. But if you're talking about ethernet cable, then I have no idea.
I just learned about these things today when researching for a device to test that there's no voltage present before installing a ceiling light. Such a great innovation since it works even through insulation, so no risk of getting shocked.
You only need 2 pairs for 100base-t, try forcing a lower negotiation, see if the pairs you need work? Maybe unbundle the other set of pairs and try them?
Wire tracker maybe?
You might want a higher quality version than that particular one if the cable run is long, one of the reviews suggest that the distance is limited.
I was curious if that would work on ethernet cable! I've seen it done on coax, wasn't sure if it would work well enough on UTP to be useful outside a lab setting. Cheap too. Cool!