I have a 5 year old Lowrance 68C that I bought because I needed both the GPS and sonar features. However, since spring, I have been noticing that I "lose bottom" often. The depth indicator number starts blinking and bottom disappears. I also have noticed that I no longer mark fish.
I continue using the unit because the GPS has been very good and the sonar works about 60% of the time in finding depth. I also notice that I lose depth most often when over 50 ft or moving on plane (though I also lose bottom when at trolling speed).
Do you think this could be my transducer or does this sound more like a problem with the unit? I know many have had issues with Lowrance product on this site but I like this unit (or should I say liked it when it worked) and frankly do not have the money to replace it right now. I'm looking for ideas to fix the unit or other things to try. I have already tried taking off "auto-sensitivity" and set sensitivity to high with no luck.
Note that even when working, I could never "see" the thermocline or bait pods...do you need high-end units for this?
Every unit I have had will lose the bottom on occasion, especially in deeper water ie, 100 ft. or more, or when going at faster speed, which changes angle of transducer.
Have you tried adjusting angle of the transducer slightly one way or the other ?
Always possible you have transducer problem but try the angle adjustment first.
I have had Lowrance units for years, never had a problem, and they track the downrigger ball on screen, so that's shows they work fine. I found them alot better than a few of the Humminbirds I owned.
Sounds to me like its the transducer. And may also need to send the unit in for the up dates. I had the same problems your discribing. And replacing the transducer and the updates did the tricks. I think it will be around $ 200.00. To get it working right again.
My brother and a freind have both had this same problem.Angle of transducer was fine in both units and the problem turned out to be the tranducer both times.Both units were also in the same 5-6 year old range.Note,I also pick up the thermocline,downriggers and bait pods on my low end unit(500 doller) polebreaker
