3DS:Traslado de tarjetas SD

Esta guía es para cambiar a otra tarjeta SD que se utilizará en la misma 3DS, ya que los datos están encriptados por consola. Si desear transferir tu contenido a una 3DS diferente, consulta 3DS:System Transfer

Esta página en pocas palabras:

Si la tarjeta SD tiene una capacidad superior a 32GB, Primero hay que formatearla: Formatear una tarjeta SD
No uses la tarjeta SD en la 3DS antes de copiar los datos a ella, ya que es posible que juegos y otras aplicaciones no aparezcan
Copia todos los archivos a la nueva tarjeta.

Transferir tus datos a una nueva tarjeta SD (por ejemplo, si te gustaría tener más espacio) es relativamente fácil, pero hay algunas cosas que debes tener en cuenta:

The 3DS can only read SD cards formatted as FAT/FAT32 (not exFAT or NTFS). SD cards 64GB and larger ship as exFAT, so if your card is of that size then you will need to reformat your SD card.
- Formatting your SD card will delete all data on it, so if there is any important data on it, make a backup of it first.
Due to cluster issues, the 3DS runs into weird issues on SD cards 200GB and larger (in particular, custom themes no longer stay applied and GBA VC has screen wraparound issues). Loading time also gets exponentially longer the larger the card is.
SD cards do not currently exist in capacities above 2TB. If you bought a card of such a size, you've been scammed. You should not use the card to save any important data (including 3DS data) due to data integrity concerns.

Assuming you've taken the things above into account, just copy and paste everything from the old SD card onto the new SD card and everything will be transferred.

Troubleshooting

There are a few reasons as to why this may happen:

The SD card is not being read; try reinserting the SD card and ensuring that there is no dust or moisture
The SD card is not formatted as FAT32
You have used this SD card in this 3DS before and it created a new data folder to avoid accidental data merging

In the final case, navigate to Nintendo 3DS -> (32-character-ID / ID0). If you have multiple 32-character IDs inside of this folder, delete the smaller one of the two.

Your SD card isn't being read and/or you don't have boot.firm on internal memory for some reason. Ensure your SD card is formatted as FAT32 and that there is no dust or moisture in the slot. If all else fails, you may want to check your SD card for errors.