I have a Lowrance Elite7 Chirp that has been working perfect. The other night I was fishing and turned it on. It went through the start up process and was working fine until I turned it off. I turned it back on later but it wouldn't show depth. It will show water temp and mph. It is showing what looks like a small line at the top of screen. Looks like structure and so forth. Does it sound like I have a transducer going bad? Thanks for any help.