Try to recover memory?

[franz.b]

thanks for the valuable information!
in fact I never found myself in the situation you describe, mostly I lost the data for low batteries...
this time, however, I don't understand how the contents of the SD card could have been lost ... I forgot to make the backup just because I knew I had the data on the card and in any case the calculator has a backup battery ...
however the most consistent damage is the loss of settings (CST menu and user key assignment) that I can easily redo and will be useful for me as an exercise