I have a FCV 585 unit, bought about 2 years ago, hooked up to Airmar, 1kw, through hull transducer. This transducer has a built in temp probe. Recently, I lost the temp reading on the screen. I checked all the settings, I think, that control readouts and look like they are correct to show temp. I don't remember anything unusual happening have that would knocked out reading. The rest of the readings appear fine-like depth and fish finder. I don't remember any inline fuses that I may need to check. Should I try to go back to factory settings and start all over? Thanks for any help.