When we were out sampling the nursery pond cove the other day was the first time my sonar has been turned on in a couple of months. It took longer than usual to fire up and when it did only the map would work. Both the regular sonar screen and the side imaging sonar screen looked as if nothing was going on. Both screens were white where the sonar returns should have been displaying and the spot where depth and temp normally are displayed were blanks (--). I tried turning it off and on several times and nothing changed its working order. I just attached a gen 3 HDS touch 7 head unit from work boat and everything worked as it should. So my transducers are fine. About the only trouble shooting info that I can find in the manual is to reset the sonar head unit. Has anyone else had this problem, know what caused it, or how to fix it? Thanks.