ST60 wind display

I have a 12+ year old ST60 wind instrument and masthead transducer. The ST60 displays wind direction properly, but displays 0.0 for wind speed. I also have a ST60 graphic display at the nav station which displays both wind speed and direction properly.

This leads me to think there may be an issue with the instrument and not the transducer. If this turns out to be the case, is an i60 wind instrument a compatible replacement for the ST60 display.

Thanks for your assistance with this issue.

Steve