Weak Return on LS-6100



My LS-6100 sounder has a weak return. Usually cannot display bottom and cannot even select a depth profile on auto mode. Is there a simple way to determine if problem is in display unit (return for repair) or transducer (Airmar B117 which would require new transducer and a short haul for installation). Unit is 4 years old with light use.
Try a memory clear on the sounder by pressing and holding the menu key while turning the display on (See page 20 of the Operator's Manual). If the system still doesn't work, chances are it's the transducer. There's no "easy" way to test the transducer other than swapping one in and holding it over the side the boat (in the water) to see if it works.
Thanks for the tip on clearing the memory. After clearing, the unit displayed a clear bottom return for a cruise to St Petersburg, FL. It was not strong enough to find a scale on either auto setting, but did perform on manual. However, on returning the next day, I could not get a consistent return in spite of repeated clearings. Is this consistent with a weak transducer and do you still think that is where I should start?

The majority of the time, the problem with a sounder is the transducer. I think it would be a good starting point.