There is a (~80m) Cat5e cable that stopped working a few days ago. I tested it with two different cable testers, and with both of them the result was: "short". Usually I get this result if there is a device connected on the other end of the cable, but this time I get "short" even if the other end is disconnected.) If the cable is plugged to switches on both sides, the lights on the switches remain off. I tried re-crimping it on both sides, but that didn't solve the problem.
What could be causing the "short" ? What does "short" could mean in practical terms in this case?