PSA: I was crimping my RJ31X jacks wrong for a solid two years

I kept getting intermittent faults on the phone line detection for a bunch of my systems in the Springfield area. A tech from the monitoring center finally asked me to send a picture of my setup, and he pointed out I was using the standard T568B pinout instead of the reversed pair for the alarm loop. I switched to the correct 4C wiring, and the problem vanished. Anyone else have a simple wiring mistake that took way too long to catch?

4 comments

4 Comments

johnson.eva1mo ago

Yeah that reversed pair thing got me too, took forever to figure out.

tessalane1mo ago

Two whole years with the wrong pinout is actually impressive. You must have had the most patient monitoring center in the business. I can't believe they didn't flag it sooner, given how many systems were acting up. That reversed pair is the entire point of the jack. It's wild that it even worked sometimes.

owens.laura1mo ago

Wait, how did it even connect? That's some weird tech magic right there. Two years is crazy long to miss that.

-1

keith1643d agoMost Upvoted

Read a thing online where someone said reversed pairs can actually still pass data sometimes because of how the signal bleeds over in cheap cables. @johnson.eva might have the right idea about it being a long term troubleshooting nightmare, but two years is wild.