I have an issue with my side and down imaging on my Humminbird. The 2d sonar and mapping work fine but when I select any of the imaging screens all I get is a black screen. I've tried resetting to default and I installed the latest update with no changes. I've messed with the sensitivity and other settings with no change. Transducer type is set to hi-def side imaging. I see Humminbird doesn't service this unit anymore so I'm wondering if anyone else has had this issue and knows of a fix for it? Or is it needing to be replaced? I am new to bird's so it's possibly user error.