Tried another receiver (puck) and it worked fine.
Pulled out the old one and re-installed the new one out of the box from one of mt 858's. Because I purchased 3 head units, I have 3 receivers so after trashing the one that does not work - I still have a spare on board.
Unfortunately I had to cut the wire off the old broken one as they were neatly installed with zip ties and buried in my wire chase on the boat - so there will be no exchange ..... lol.
Funny how things only a few months old crap out sometimes ........... is this a common thing a guy should keep on board as a spare (like a transducer)? I was really surprised to have this receiver fail so early ........