Casio BOSS SF-5300

Once the DATA ERROR DISPLAY appears,You will not be able to INPUT or EDIT DATA, though you will be able to recall Data after pressing CLEAR to clear the error message.**YOU WILL
WANT TO SAVE ALL YOUR DATA OR WRITE EVERYTHING DOWN AT THIS POINT, BECAUSE THE ONLY WAY TO GET
THIS DEVICE BACK TO NORMAL OPERATION IS TO PRES RESET IN THE BACK -IF YOU PRESS RESET YOU WILL LOSE ALL INFORMATION PERMANENTLY.


In order to return the memory to normal (allowing further input and editing of data), you must perform the RESET OPERATION to clear the memory of all data-Make sure you have backed up or taken a hardcopy of this information before Resetting or it will be gone and there is nothing you can do to get it back.Once you have RESET you can re-input the data you have written down.

WHAT CAUSES THE ERROR MESSAGE?Interruption of battery power.Severe electrostatic charge,impact,change in temperature
or humidity.Hardware Problem.

Recommendations:Replace batteries every 2 years, regardless of use.Use only CR2032 Lithium batteries.Replace all batteries-Never mix old ones with new ones!
Caution: All data stored is lost if you remove more than 1 battery at a time. The following Info is per the instruction manual-WHICH ALSO SAYS :Be sure you keep a separate copy of all important data that you store in the SF-5100/SF-5300.Hope this helps.

I've found a hard copy manual. It said:

Note that once data is lost it cannot be recovered. Such data errores are generally caused by one of the following problems.

- Interruption of battery power
- Severe electrostatic charge, impact, change in temperature, or change in humidity.
- Hardware problem.

Once the Data Error display appears, you will not be able to input or edit data though you will be able to recall data after pressing CLEAR to clear the error. In orden to return memory to normal (Allowing fruther input and editing of data), you must perform the RESET operation to clear the memory of all data.
When battieres go dead, of i've you have a mistake replacing batteries, the data stored in memory may be damaged or los eneterly.