Hacking Corrupted SDcard problem? Need help to recover

[xmp8851]

I have O3DS with emunand. Luma3ds, godmode9 are latest version

Cannot boot into emunand, sysnand boots but say sdcard corrupted.

Godmode9 detect all the partitions including emunand and sdcard but cannot backup emunand even if I 6GB left on sdcard


What is my 3ds' problem and how can I fix it without losing any data?

edit:

I just backup emunand.bin, copy all the files in sdcard and then format my sdcard.
Fixed after restore and paste things, but dont know why it happend

 

[BaamAlex]

Why emunand? This is obsolete...

 

[xmp8851]

Why emunand? This is obsolete...

It's japanese 3DS and I just want to keep japanese firm cuz i have some japanese cartridge and want eshop and update.
Sysnand is japanses firm and Emunand is not.