I need to be more specific. These are two separate switches that I'm having problems with. One particular switch is connected to the main router thru the main switch that's in another building. It's connected with a fiberoptic cable, transmitter, not a cat5 cable. I tried the cable from the switch that wasn't working, on a known good switch and it worked fine. I then tried changing the transmitter part, and it didn't light up, so I figured it was a bad part, I replaced that part, and it still doesn't work.