I have a Sharp Electronic

I have a Sharp Electronic Organizer IQ-8000 64KB (circa 1992) which would not turn on. So I replaced the operating batteries then a message displayed
"The Organizer is not initialized or memory has been impaired.
Emter [Y] to INITIALIZE and CLEAR ALL MAIN memory contents."
This horrified me - so I replaced the Memory Battery also and the same message displays.
I do not want to clear all main memory contents.
What can I do to retain all the memory and get it working again?
I am in Brisbane Australia.