[philjam]

My CS JVX18 came with a Lowrance Elite 4. I have not seen any fish curves, just vertical lines that look like trees (there are no underwater trees there) and a bunch of hash on the surface. It is used in the Pamlico River at depths from 2' to 50'. It is wired to the cranking battery and the transducer is to the side of the skeg. The sensitivity is at 83 mhz. I read the book but did not do well on reading comprehension in school. HELP

 

[sundrop]

reduce the sensitivity until you see just smooth bottom. Check your transducer and make sure it hasn't been bumped and pushed up a click and also that it extends below the hull and wasn't installed wrong. It has to be parallel to the bottom while you are in motion.

 

[Alotahp]

also turn off noise reduction.

 

[Neilslure]

Any screen shots of what you are seeing?

 

[FishinCary]

Vertical lines that don't scroll (static lines) to the right as the screen moves can sometimes be due to electrical interference (or so I've heard). Check to make sure your transducer cable runs through your hull away from other cables.

•Disconnect the transducer and turn on the unit. It should enter demo mode and you can make sure the vertical lines are an interpretation from the transducer and not just a faulty head unit. Report back on if the black lines show up on the demo mode too.
•Make sure your transducer is below the water line and has water flowing OVER the transducer at all times. Make sure the reading face of the transducer is parralel to the bottom (of the lake).

Could you tell us:
-How wide are the black lines?
-Are they static or are they moving across the screen?
-When are they visible? Just when the unit is fully on? Can you see them when the unit is powered off?