I have some 10m 2-pair shielded Ethernet cables. One works intermittently, and waggling the cable at one end makes it work/not work.
It is manufactured by the now defunct GFI Global and was supplied by BT. Plugging it into an RJ45 tester shows 1, 2, 3 and 6 to be connected without issue. However, the ground is intermittent.
The lead is used to connect my computer to another lead with a Cat5e coupler, meaning at the coupler end there is no ground/screen anyway. Yet, intermittent ground causes the connection to drop. I even switched the cable around, end to end, so that the faulty end was into the coupler, meaning that the ground in the cable is connected to the computer, but that the bit of metal surrounding the plug was intermittent, and still it failed. It only requires four wires, so why is the ground within this cable so important?
I am hoping to repair the cable with a non-shielded RJ45 plug, of which I have supply. Might this be doomed to failure?