Sometimes see bottom, but as thin line

[Anonymous]

I have a 620 machine that has worked flawlessly for several years, but this past week it started showing bottom as a thin blue line, then many times does not show bottom. I fish the same areas every day and usually the bottom is wide and orange.

 

[Snips]

Madmescan,
Are both frequencies weak? If so, you could reset the 620 to it's default settings? If it is still weak after that I would suspect the transducer.

Snips