Re: Lorance 510c
My first thought would be this is a problem with the unit itself. If you can get your hands on a spare transducer, the next time you are on the water unplug the current transducer and plug in the new one. Put the new ducer over the side into the water and see if this corrects the problem. If it does you have your fix, if not call Lowrance customer care for help with the unit.