I didn't use my SN10 for a few years. When I start it up, I get a
screen saying "SRAM is invalid. SN10 needs to be recalibrated...."
What's this?

Also when trying to connect to the PC with PC-link I get the screen
"PC link started Press HELP"., but it doesn't go further. The pc
recognizes the SN-10.

Thanks,
Dan