So I have recently found out that all my phone sockets have been wired with cat5 or cat5e cable. I don't know which.

I've upgraded my internet so thought about repurposing the cables as patch cables. My intent is to patch my computer in the office upstairs to the router downstairs.

There were 7 phone sockets in the house, and 6 of them had 2 cat5 cables in each. I have cut them all out and added rj45 connectors to all of them except the one. I then used a tester to find out which cable went to which room, hoping I can daisy chain from.the office to the front room.

But as luck would have it. One of the cables went directly into the room. I couldn't believe my luck.

Sadly, when I use the cable tester it cycles through 1 to 8, but conductor 5 doesn't light up. Does that mean it's dead?

I've never done patching before but I checked the order of the wires and they are fine. I even cut them off and redid them but got the same results.

I also thought the cable might work but would be slow as conductor 5 isn't used. I plugged in my PC and no lights came on. Nothing.

Is there anything I can do or is it just rotten luck?

  • 2
    I would believe your tester. A kink in a cable or stretching it when pulling on it can break a wire. I have seen both happen. I am very gentle with cables.
    – John
    Jan 29, 2021 at 20:23
  • Does the tester have a button that toggles testing ground, or something like that? Jan 29, 2021 at 20:24
  • Thanks John. Sadly I suspect you're right and will have to just leave it. Jan 29, 2021 at 20:29
  • Thanks user1686, it's only a cheap on so just cycles through when switched on. It does have 2 switches but it just seems to vary the speed it cycles through. Jan 29, 2021 at 20:30

1 Answer 1


However you might not be out of luck completely. If you have 4 working wires, you can connect at 100 Base T. While not gigabit, depending on your usage, it may be fast enough. Best of all, it doesnt use pin 5.

The thing that concerns me is that a modern network interface should try to negotiate at 100 Base T, if it fails at gigabit. The fact that yours didnt, makes me think there is something else wrong with the wiring. You can wire for 100 Base T with the wires that supposedly work. If it still fails, you can manually force the interfaces to 100 and try, as there is nothing to lose.

Here is a wiring diagram for 10/100/1000 Base T.

Alternatively, if you are looking for a reliable high speed, wired solution, you can always go with powerline networking. Adapters are relatively cheap and easy to set up.

  • Thanks Keltari, I was with you and was surprised when I plugged it in that the lights didn't come on. I even tried changing to 100mb full and half duplex. Nothing. I've invested in a mesh network which is great but on voice call I get the odd drop out which is why I was looking to ethernet. The mesh gets me 250Mb so it's better than 100 base. I am just too curious to let it go. Jan 30, 2021 at 23:15

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