memory settings all lost on camera, when turning on

I have had this Coolpix S9500 for some years - it has for a long time been difficult to turn on - when it finally is turned on, all settings are back to basic ( dates + and all other settings ) - very annoying to experience that, just when wanting to take a photo ……….

I have tried many things - but NOT yet replaced the internal memory battery

Can anyone help ? Have you had this problem ? ?