Ethernet cable no connection - how to trace?

[readiescards]

Got approx 30 ethernet cables running around the house and down the garden.  Slowly bringing them into use, 10 working great, 20 untested but one is not working t all i.e. ethernet cable testing tool gets no response from far end for end pair.  As it happens this is the longest run of approx 40 metres and I can see the cable at 3 points along its length or at least I think I can see it - I can't be 100% sure it is not another cable. Luckily this cable is a slightly different colour to the majority of the others (being Cat5e instead of Cat6) and both ends of the supposedly same cable are the same colour so it 'should' be the correct cable.  So I want to confirm it is the same cable along the way and if so try identify where the fault might be in case it is patchable.

 

Question how can I trace a fault on an ethernet cable without buying yet another tool or ideally not cutting the cable?  I've multimeters, radio wave detectors, ethernet cable tester, Raspberry Pis, metal detectors, A/c and joist wall detectors and I've just ordered a multimeter with a square wave output, plus various electronic components gathered over the years.

 

I'm thinking of injecting a signal in one end and seeing if any of the above will pick it up but am open to any other ideas.

 

[Jeremy Harris]

I have a tester that I made up that tests using DC sent down each pair in turn, using a microcontroller to run a step pattern down the cable and a simple group of four LEDs on the end of a plug that checks the distant end.  The way it works it to put DC down each pair for a couple of seconds, then switch to the next pair, then the next pair etc, so what you see at the receiving end is a moving light display, that shows if all pairs have continuity, or if they don't, which pair is dodgy.

 

I found that the two or three problems I had were all down to bad punch downs by me.  Hooking the duff wire out of the IDC and punching it down again always fixed the problem for me.  Curiously, none of the flexible cables I made up had problems, yet it's far more fiddly to feed 8 wires in order into the back of a plug and crimp then down with the tool.

[Vijay]

any help - https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2505460.m570.l1313.TR3.TRC1.A0.H0.Xethernet+cable+tester.TRS0&_nkw=ethernet+cable+tester&_sacat=0

[Temp]

+1 on the punch downs being a common problem.

 

I'd look at that first and perhaps just remake or perhaps make up a dongle that puts a short or say 270R across one of the pairs and look for that from the other end just to check you have the right cable. 

 

[Temp]

Perhaps worth remembering that of the 4 pairs you actually only need 2 to make an 10baseT connection. So if it turns out one or two pairs are broken half way along the cable the simple answer might be to wire up the remaining pairs.

[dpmiller]

I've a handy tester that can tell you the total length of the cable as well as the distance to a fault. They're pretty dear to buy but if you're stuck I could send it over for a try?

[readiescards]

4 hours ago, Vijay said:

any help - https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2505460.m570.l1313.TR3.TRC1.A0.H0.Xethernet+cable+tester.TRS0&_nkw=ethernet+cable+tester&_sacat=0

That's the little tester tool I have, indicating no connections at all.

[readiescards]

3 hours ago, dpmiller said:

I've a handy tester that can tell you the total length of the cable as well as the distance to a fault. They're pretty dear to buy but if you're stuck I could send it over for a try?

That would be very kind and appreciated if I can't work it out.

 

I've tried remaking one end will try the other too but visually seems ok

[Nickfromwales]

A tone generator set is what I use.