Happy new year!
Your problem sounds very interesting. and similar to mine. I had a humminbird 788ci. worked great for a few months then started doing the same thing. i sent it to mfgr and they sent it back with a new transducer. i put the new one on. Worked good for a week and did it again. It worked great on ontario, when i came back to my home lake, seneca, it did it again.. Needless to say I gave up, sold the boat and the bird. time to start new, LOWRANCE is now my only choice. i wish you luck, and remember youre not alone..
see ya on the water,
Nick
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