Head scratcher fault: Dead network port 2013
I got called out to a customer the other day because one of their PC’s had dropped off the network. Somebody had been a bit heavy handed and popped the socket out of the face plate so it was in the cavity but it had previously been working.
Using a simple network continuity tester I was getting continuity on Pins 1, 2, 3 and 6 which is what I would expect if it was plugged into a 10/100 switch but still no network connectivity.
The socket was marked as 16 so I checked at the patch panel end and there was no light lit on the switch port. It was also a gigabit switch so I should have all 8 pins connected.
I plugged the other end of the continuity tester in and got no continuity on any pins. I attempted to use a tone source to identify that the cable was actually getting to the patch panel but couldn’t find the tone at the patch panel. I plugged the continuity tester back in with the patch panel port unplugged and I still got continuity on pins 1, 2, 3 and 6.
Puzzled by all of this I decided it was time to get serious, got a ladder and lifted a tile to see what was going on. As I was moving the tile over to make sure it wouldn’t fall a Tenda 8 port switch fell out!
All became clear as the Tenda switch was powered down. I tried plugging it into another power outlet in the ceiling space but it still didn’t power up. As it was only being used as a cable extender for 1 cable and there was enough slack on the feeder cable I simply pulled it down inside the wall, put a new socket on it and popped it back into the wall plate.
The PC on the end of this cable would have only been getting a 100Mbps connection when all the others would have been getting Gigabit connections off the recently installed Brocade switch.
I always say to customers you can hide a multitude of sins in a suspended ceiling but to put an active device like that up there for no reason in this case is just wrong. The wiring that was done when the place was partly renovated several years ago leaves a lot to be desired.