Why is my Helix DI not showing any structure?

I am having problems with my Helix 10 DI g2n not showing any structure. I have to put my settings high just to get a bottom reading and then it doesn't show brush or fish or anything that my 2D is showing. Help please?!?

You probably have a weak transducer or faulty unit processor. Others with the G2N's have experienced the same thing.

Is the operating software current?

Yes it is current. They have already replaced the circuit board once before.