Troubleshooting the ethernet wiring in a house

We moved into a new house that has Ethernet (Cat 5e) wiring throughout, great! Except they didnt put RJ45 jacks on the ends of the cables in the otherwise very nicely organized cable box in a closet. The cables are also not labeled so I have no idea what goes to what room.

I've never crimped an ethernet cable before and the internet installer wouldn't do it so I got a kit with a crimping tool, tester, RJ45 connectors, and several Youtube tutorials. I got a Netgear 16 port unmanaged switch and got to work putting the connectors on after several practice runs that the tester say went well. I used the B cable order without knowing which they used for sure, but as I understand it I should be seeing a signal, just crossed over with the tester if I got that part wrong.

I went ahead and set up all 10 cables before testing them, because of course I did, and I went around the house with the tester trying all the ports. None seem to be getting any signal with the tester and my PC isnt picking up the internet over ethernet.

Im not sure where to start troubleshooting this. I tried redoing one of the connectors after another trial with a spare piece that went fine. I tried connecting the tester to one of the closet wires and then going around the house plugging the other tester half into every port, no test signals. The internet installer took one of those wires, put a connector on and connected it to their modem and that part worked just fine. I even opened one of the jacks to see if there was even a wire behind it and there was. Im not sure how to tell if its properly set up but it didnt look wrong.

Im at a loss. Any ideas before I call a pro? Im not even sure who I'd call.

So you started off with male plugs in the cable box, and female receptacles in the rooms? Or were they just bare wires on both ends, or what? Were you able to test that they worked before you started making changes?

Frankly, I might start off with a simple multimeter test on one of the runs of wire, just to make sure the previous owners didn't do something crappy like sever all of the wires somewhere in the walls, before they moved out.

Female receptacles in the rooms, like you'd see in an office, no plugs in the closet, just the bare ethernet cordage. I put male plugs on them to attach to the switch. This house was a high quality remodel. Every part of the inspection turned up great so while the wires being cut somewhere behind the wall would explain what I'm seeing, its highly doubtful they'd f*ck us over this one way when everything else showed care and attention to detail.

My signal testing method is one end of the tester plugged into the wall via a 2nd ethernet cord, then I go to the closet and connect the other tester part to each cord I've added a plug to. There were 9 plugs in the closet and none is getting any signal through the tester no matter which wall port I try. Is there anything wrong with that test?

Have you pulled out one of the wall jacks and see if the wire's actually connected to the jack? If they didn't hook up RJ45s in the closet, it wouldn't surprise me at all if they also didn't punch down the cables into the jacks. That seems like the most likely scenario that'd lead to all the runs not passing a signal.

The good news is that punching down cable into a wall jack isn't really any harder than crimping rj45, the tool is cheap, and it's more satisfying.

Chaz wrote:

Have you pulled out one of the wall jacks and see if the wire's actually connected to the jack? If they didn't hook up RJ45s in the closet, it wouldn't surprise me at all if they also didn't punch down the cables into the jacks. That seems like the most likely scenario that'd lead to all the runs not passing a signal.

Yeah, this is a much more likely (and friendlier) scenario than I suggested above. Might be that the remodelers just ran out of time/money and didn't know how to actually do cat5 wiring... or left it as an exercise for the buyer -- maybe they didn't know whether you'd prefer the A or B wiring method (lol).

Are you certain that pin 1 on the female side is the same color as pin 1 of the male side, and that the colors are all the same from there? With the clip facing downward, pin 1 is to the left when the male end is facing away from you, and when the female end is facing toward you. If one side is reversed from what it should be, that's not a crossover configuration. Many testers won't show any sort of connection at all.

IMAGE(https://i.imgur.com/se5t2Fp.png)

EDIT: By the way, most of the time T568B is correct. Not always though.

When I was a youth, working with the town's master electrician (running ethernet wires in the schools), he had us using T568A for the male-male crimped cables, and some crazy scheme for the female receptacles. Never assume.

And yes, 25 years later, having only crimped 2 cables since then, I still have those wiring schemes ingrained into my brain.

merphle wrote:
Chaz wrote:

Have you pulled out one of the wall jacks and see if the wire's actually connected to the jack? If they didn't hook up RJ45s in the closet, it wouldn't surprise me at all if they also didn't punch down the cables into the jacks. That seems like the most likely scenario that'd lead to all the runs not passing a signal.

Yeah, this is a much more likely (and friendlier) scenario than I suggested above. Might be that the remodelers just ran out of time/money and didn't know how to actually do cat5 wiring... or left it as an exercise for the buyer -- maybe they didn't know whether you'd prefer the A or B wiring method (lol).

When we added an detached home office to our house, I had the electricians run Cat6 from where the internet comes into the main house down to the office, and they didn't terminate either end of the cable. When I asked them about it they just said that's not the electrician's job and didn't explain any further. So ... I dunno. Maybe there's some liability thing related to it? Or they don't want to be responsible for troubleshooting issues when people complain that their internet doesn't work?

Regardless, as mentioned above, terminating the cable is easy, fast, and cheap.

Wow, they did T568A. I took out a wall unit and inspected the wires. The unit helpfully has a color coded A and B guide on it. Their wiring matches up with A

So should I convert the wall units to B or my closet connectors to A? There's not much slack in the wall units to be able to cut back and re do it, so Im thinking convert my closet to A unless I hear a good reason not to.

Will the A/B thing affect what ethernet cords I can use to my PC and other devices?

Trying to think back to my dimly-remembered time in networking 20 years ago.

Try the lazymode solution first. Connect from 1 closet port to your router with a crossover cable (a-to-b), then use a cable you already have on hand to connect your PC to the wall. Does it work? Good, then buy/make more crossover cables for the closet connections.

Crossover adapters are cheap on Amazon.. I'd just buy a bunch and save yourself the hassle of doing it all over again.

TheGameguru wrote:

Crossover adapters are cheap on Amazon.. I'd just buy a bunch and save yourself the hassle of doing it all over again.

Let the next sucker who buys that house find out the hard way.

A/B doesn't matter whatsoever, as long as the connections on each end of a given length of wire are matched. Crossover wires are cheap, sure... but if it were me, I'd get antsy every time I looked over at that wiring closet, until I converted them all to type A.

Yeah Ill be converting them to A tomorrow morning. Thanks for the input. Hopefully I wont be back for more help

Hopefully you WILL be back with a success post, and maybe a picture of an oddly-satisfying neatly arranged home wiring cabinet?

Crimp well, polypusher. Crimp well.

We'll see!

If the wall ports are t568a, does my pc need a crossover cable to connect to the wall?

polypusher wrote:

We'll see!

If the wall ports are t568a, does my pc need a crossover cable to connect to the wall?

Nope. If each pin on one end of a cable goes to the same pin on the other end, the signal doesn't care what color that wire is. Crossover cables (which are totally a different thing) were a thing back before Gb ethernet eliminated the need for them.

The two wiring standards are for ensuring each twisted pair on a given cable is used in a way that ensures a certain maximum cable length without interference between the wires. You can use an A cable one place and a B in another. As long as an A is an A at both ends and it's the same for the B cable, it doesn't matter.

Well I switched them all over to A and still nothing

The crimps seem ok so I'm out of ideas.

Does your tester also do toning? You might be able to connect the emitter to one end of the line, and use the receiver to trace the wire through the wall, and maybe find if there's a break or something that you didn't know about.

It was a cheap tester that came with the kit. Im not sure what that even means.

At this point Im ready to just upgrade the wireless hardware on all my devices to get close to the 1gb I'd have gotten wired.

Don't do that. You should be all over the builder at this point. Get a network pro out to diagnose your problem. If that problem is the builder doing it wrong, then you should be able to backcharge them to get it done correctly.

edit: assuming that this is a newly built house, which is what it sounds like. It really sounds like they f*cked it up.

If it was my builder definitely. They worked for the remodeler though and we bought the remodel. I dont think I have any rights to this point past the initial inspection (which is like 'what's ethernet?') and purchase of the house.

What a toner does is attaches to one end of a wire, and sends a signal down it. Then you take the other one, and when it's physically near the wire, you'll hear an audible signal. So if you've got a bunch of wires at a patch panel, you can touch each one and see which one goes to the wall plate you're interested in.

But the other thing it can do is follow the path of the wire. Basically you should be able to hold the probe unit against the wall and follow it along. It can get messed up by anything between the probe and the wire, like thick insulation or other wires and pipes, but it's worth a try. If your tester doesn't do it, ones that do aren't expensive. I got this one for about twenty bucks, and it does the job. It's a handy thing to have around the house, since they can do that trick with regular wiring too.

polypusher wrote:

If it was my builder definitely. They worked for the remodeler though and we bought the remodel. I dont think I have any rights to this point past the initial inspection (which is like 'what's ethernet?') and purchase of the house.

So they messed up the remodel, and you should still have recourse against someone.

You need a fluke that will tell you if all pins are good the entire length of the run. Its the best way to see cuts or bad patches

Editing a not helpful post.

Pick a wire, focus on tracking it back as far as you can. Here's a thing I learned: many installers treat Ethernet cables like more tolerant phone lines. The cables are often stapled to the studs. You get a new kid on the stapler and an enthusiastic ka-chunk later you've got a dead line or three in the bundle.

Edit: I've been told that this is also why many installers are using Cat5 for phone lines these days. More likely to find a still working pair if you've got 8 strands to choose from.

TheGameguru wrote:

You need a fluke that will tell you if all pins are good the entire length of the run. Its the best way to see cuts or bad patches

Sure, and Fluke equipment is expensive as hell. It would be cheaper to hire in a network pro, who should already have one.