C80 GPS, speed, temp and FF info not displaying

[ddfour1]

Bringing the boat out for the season, my C80 MDF was not receiving a GPS position fix but the chart was working and was showing the boat position on the chart.

Also, the C80 was not able to display speed, water temp or fishfinder information.

I did have batteries replaced and wonder if the C80 reset itself and has reverted to some default setting. I should note that my waypoints are still stored so the reset may not have happened. My tri-data is also not showing speed and depth.

Any thoughts on where to start diagnosing the issue?

Thanks

Dave