I have a brand new, straight out the box SXT SA5 ac. Plug in the PoE power, connect up the ethernet. The LED on the board inside the unit lights up, so the circuity has power, but there is no connection on the ethernet (router LEDs don't flash), no response to ping 192.168.88.1 and connecting directly to PC ethernet and running winbox doesn't detect anything either.

Is there some secret power switch that is undocumented that needs to be turned on? How do I boot this thing?

Is anyone able to offer any advice on how I could test this? Does it need a special ethernet cable to my router?

You should try with another poe

You should try with another poe

Thank you for the suggestion. I have done this and it makes no difference.