Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do what I can to provide the right answer to your question.
First, yes, there is a solution to that problem. Possible, or probable, is the nature of the solution I propose.
In outline, you need to check - and, clean - the connection to your sonar transceiver or 'sounder'.
Here's how to do the task:
1. Turn the equipment Off. Then trace the entire length of the connection from the Bidata to the sonar transceiver. Look for any sign of severe bends, strain, cuts, and other damage.
2. examine the sonar transceiver in its mounting (whether through-hull or in-hull mounting type.) Has it been shaken loose? or worse, is water leaking through around it (if it is a through-hull type) ?
Think back and recollect whether there has been a collision or grounding, however minor or major, that might have damaged the sonar transceiver.
3. then undo the connections (one at a time, only) from the Bidata to the sonar transceiver. Brush each side of each connection, jack and plug both, with a clean dry brush, thoroughly. Then wipe each side of the connection with a clean dry rag cloth, until the metal shines. This eliminates the corrosion that is so common in maritime or other sailing environments.
4. then re-connect the connection firmly. (And if there is another, go on to the next.)
Try the equipment again after that.
Let me know the result, please, whether favorable or otherwise, in Reply. I offer further advice as needed, and I like to hear if my advice has had a good result (or even, if there's a good result from other means!) Thanks.