i do seem to remember that the last time I updated the firmware on the card it just did it when i selected the card in the main menu. I don't remember selecting 'config' and 'upgrade', etc... but i could be mistaken. its been a while since I updated the card.
I'm having a similar issue with as an R41 3DS SDHC card. Trying to update card to v1.68b. I have 2 3DS's. The first one was accidentally updated to v5.1.0-11u. I have copied the v1.68b files to my sd card. I get the black screen on the first 3DS when the card is inserted. The second 3DS is still...