Fusion radio won’t turn on

[Sowie]

So I have a 2020 275se with the fusion bb300 stereo. It quit working suddenly and acts as if the connext system doesn’t recognize it anymore. The connext screen says to turn on the radio but when I hit the button on the screen nothing happens. All the selections for stereo source have a lock symbol next to them. Thinking it was a bad bb300 and getting just a red light at the unit fusion sent me a new one. I plugged the new unit in and now red light comes on for 1 second then turns amber for a few seconds then all goes off. No radio. I have checked fuses and wiggled nk2 connections. I have 12v at nearest nk2 under helm where it adapts from the round yellow cable to a standard 4 wire going into the wiring loom. I think I have a can bus problem but I only know enough about these to be dangerous. I am hoping this is a similar setup to the new 255 boats as there aren’t too many of us 275’s out there. I have been messing with this for two weeks and trying to ready her for the Memorial Day weekend. Also I believe that the brains of this may lay in the SPU black box which is under the starboard seat in front of the engine head wall. There is an amber light blinking on the box. Does anyone know if that is normal or if it is trying to tell me something. Thanks all.