AfterDark
Contributor
Can be a wear and tear issue. It's important after every dive to submerge the unit in fresh water for a a few second and press all the buttons. To clear the saltwater and build up. So once it dries there are no saltwater crystal build up.
If cleaning and rinsing is not working. Send to repair. Upon return maintain it thoroughly...
Someone told me warm fresh water is even better to flush the salt.