I have a new(to me) Elite 7 HDI that is having a Down Image problem. The 2D sonar is working well and giving good readings on both 200hz and 83hz. The down imaging, however, is giving very weak returns (bottom is not even distinguishable most of the time), and apparently no return on 800hz (black screen). Have tinkered with ping speeds and background colors to see if it was a display problem, with no improvement. In simulator mode, the display gives a clear sharp picture.

Has any one had this issue before?