Speed indicates zeros

[Pat]

I have the Autohelm (Raymarine)ST 50 system -wind, depth, speed, GPS, chartplotter. The speed was working fine then all of a sudden it went to 0.0. I pulled the paddle wheel to see if it was fouled but it wasn't. All other instruments work ok. I did also press and try to reset. I am not sure if I somehow turned this thing off? Any experience out there with the same issue. Thanks.

 

[Steve]

Knotmeter problems

First thing to do is to make sure that you see a reading on the instrument head when you manually spin the paddle wheel. If you see a reading then the paddle wheel was not clean enough. No reading is more of a problem. You should probably call Raymarine and get Technical Support. I had them help me out on AWI and autopilot problems and they are really good. Since the leads are potted into the transducer you cannot check for continuity. Perhaps they can give you voltage ranges for normal operation and you can check them in at the back of the instrument. BTW, one of my problems was a badly soldered connector on my AWI so I redid the connector and most of my problems went away. With many Raymarine instruments the next step is to reprogram back to factory default settings and work from there. Raymarine can advise you on this since I am not familiar with the ST50 knotmeter but it is probably similar to my ST40. If all else fails, you can send the instrument head to Raymarine and they will check it out and repair as needed. Any god instrument shop can bench test the head at a reasonable cost. My local shop in Annapolis did this on my AWI for $30. If in doubt about whether to do that you might be able to borrow another instrument head from your local shop and hook it up to your transducer to convince yourself that the transduced is not at fault.