ST 30 Bidata Depth Reading

[rmason1]

I have an ST 30 Bidata Speed/Depth instrument fitted to my boat. The depth reading has suddenly ceased to indicate the correct depth and is showing zero. In addition the 'Metre' legend is flashing continuously. I have visually inspected the cable from the Transducer to the rear of the Instrument and also the security of the connections. All appears well. I have been told that it should be possible to hear the Transducer 'Pulsing'. I have used an Engineers Stethoscope to try and detect this but without success.
Is it possible that fouling on the Transducer may be causing the problem? Also, is it possible to check out the operation of the Transducer without lifting the boat out of the water.
Any advice would be much appreciated

Regards

R Mason

 

[Barnacle]

This happened to my instrument on the first day of our 3 week summer cruise last year, ended up using a lead! The pulsing of the metre legend just indicates there is no depth input. It turned out to be a fault in the instrument head and it was repaired by the makers by renewing the circuit board, but cost about £150, for which I could have bought a separate new depth sounder! If I were you I would go out and buy a new ST40 depth, which you can get for £160 including a new transducer (less if you just buy the head) but I bet your old one is ok. You can then put the new head along side and just use the bidata for log.The only way you can really check the system is to substitute a good head for yours, fine if you know someone with one spare, or willing to take their boat to bits! No doubt a good Marine electronics man would be able to do it, but it will cost and in the end I doubt it would be economic if the instrument is out of warranty.