I have Raymarine and its given me a few problems. The radar
stopped working and then the chartplotter
would blink on and off every few seconds. Cleaned the contacts and then reattached cables
one at a time to the chartplotter. Bingo! No problem on the chartplotter until I reconnected the radar cable. I suspect that something in the radome is drawing too much power causing the plotter to shut down.
Raymarine did have a .pdf file for diagnosing what's wrong but that will mean climbing the stick to get to the dome. It's on the list, maybe I'll get to it in a month or so. Were I to do it again, I would choose Furuno.