Greetings Vawaterman,
Well it kinda sounds like it's either missing a MMSI, it's in silent mode (check to see if you have GRY and PPL wires in your cable assy.), the software update needs to performed again, or it's an issue with the radio or it's GPS receiver. If you suspect the unit is faulty, you're more than welcome to send it in to Furuno USA's Camas, Washington Service Repair center for a service evaluation. They can quickly determine the condition of the unit and assess what next steps are needed to getting it back operational.
- Maggy