It sould like you have other SEATALK devices on your boat. Were they on the boat before you instaled the C80? If they were they are receiving power on the Seatalk buse. THe Seatalk buse has three wires Red (12v) Yellow (Data) and Black/Shield (ground). When you install the Raystar 125 you need to make sure that you follow the instruction when you have other seatalk devices. Based on your discription the green light flashing means the device is receiving a fix. The data (yellow wire) is not getting onto the buse so that the C80 can receive it plus the TRIDATA is no longer working which also implies that the buse has a proble.
Hope this helps