I have "inherited" an old SFTP Cat5e cable connecting the basement of my house to the upper floor. There seems to be a break on some of the wires (6 and 7) so it won't even function at 100mbps.

I think the breaks may be in the connectors themselves, as they appear to have been crimped very (very!) poorly. In fact, the shield doesn't seem to be connected to the connector at all at one end!

I don't really want to rerun this cable (for a start I have no idea where it actually goes once it leaves the basement) and I would like to recrimp both ends of the cable to see if it's just the connectors or if there is a break in the wires inside the cable. I only have ordinary Cat5e connectors handy.

I'm guessing that the entire run is less than 40m and that there was no actual reason to use SFTP vs UTP in this case. There don't seem to be any sources of major interference nearby so I can't imagine why the more costly SFTP was used in the first place.

Will replacing the existing shielded connectors on the cable cause any problems? Obviously the shielding won't be grounded - but it doesn't seem to be at the moment anyway - and I've heard that an ungrounded shield is worse than unshielded because of the "antenna" effect, but this page seems to contradict that:


Will ordinary unshielded RJ45 connectors be OK, or at least not much worse?


  • 3
    \$\begingroup\$ You should be able to run at 100MBps over the intact pairs (100Base-TX uses 2 pairs, not 4) \$\endgroup\$ Aug 13, 2017 at 17:29
  • 2
    \$\begingroup\$ You can't hurt anything by replacing the connectors, and if the replacements don't work, you can replace them again, or try something else. \$\endgroup\$ Aug 13, 2017 at 18:34
  • \$\begingroup\$ Only one end of the shield should be connected, otherwise a ground loop (a bad thing) could be created. Only ground the upstream end to be consistent. \$\endgroup\$ Aug 18, 2019 at 16:41

1 Answer 1


Yes, ordinary unshielded connectors will work fine.

I would suggest however, not just crimping the 8P8C male connectors on, but use an 8P8C female Jack on each end. Then just use a patch cord. Although the 8P8C male connectors are often crimped on to the ends of infrastructure cabling, it is far less than ideal, and they do not tolerate flexing or plugging and unplugging gracefully.


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