Garmin UD54 Chartplotter and Airmar 19 transducer problem

[Inizio]

Hello All..
I have a 1988 Catalina C27. I just purchased the vessel and it came with a Garmin UD54 Chartplotter which has an integrated depth finder function. The sensor is an Airmar P19 through-hull sensor. During the sea trial sail this setup worked perfectly.

Upon taking ownership I did a reset of the Garmin to faciltate associating my email as the owner and admin on the Garmin system. Lo and behold the depth finder stops working. When it is in Sonar mode the screen shows a blue background with static-looking lines of white dots.

Calling the good folks at Gatmin and spending a total of 2 hours on calls to reconfigure the system was not fruitful. I am now considering adding a stand-alone depth gauge with a glue-in sensor. I would rather not if I can get this one working. BTW: the chart-plotter is 3 months old (appx) and the sensor is a similar age.

Does anyone have any experience with this setup or suggestions on how to get it working?