You'd have to hook it up to a NMEA2000 network to power the port (separate from the AP) and use a MFD or a PC with Acntisense NGT-1-USB or NGX-1-USB and nmea toolbox software to see if it shows up on the network. Or connect the AP to a working network with other devices and see what's in the device list on the AP. My bet is on the network. NMEA2000 being a bus network is not that easy to troubleshoot. Gotta check things carefully and/or divide and conquer the network to diagnose.