I have had that problem in the past and spoke with tech's who told me to do cold reboot of the machine which fixed the problem. Call your tech department for whoever makes your unit and I'm sure this is a quick fix.
LOL Yes it is an older hummingbird 200s? i think? transducer is mounted on the back Im a newbie so not sure what a "chime" is ? but yeah this is the first year we have a problem with it, It's a brand new battery we just put in at the beginning of the season, and the voltage seems ok? not quite sure maybe i should go get a Walmart "Frenchman's Special" and try that LOL Take CAre God Bless and Tight Lines LOL Donkey Dave From up North "The Backwards Frenchman" thanks for tips guys!!!!!!