Lately, my echomap ultra 126sv has had a problem with displaying the proper depth at the top of the screen. It displays proper depth at the bottom of the screen, it is just the dept at the top of the screen that displays wrong.

It will be in 25 ' depth and it will display 5' or 6' of depth. Usually a fraction, such as 5.6'. When I am in 15' of water it will show 1.1 or 1.2' as the depth. But it does not display the wrong depth constantly.

It will show 1.1' for a minute or two, then will display the correct depth of 15.6' for a few minutes. Then it will show 1.1' again for a short period of time. Back and forth every few minutes.

As I said, the bottom is displayed properly and you can see the correct depth along the side of the graph, it is just the displayed depth at the top that keeps changing.

Does anybody else have this problem and have suggestions as to how to correct it?