Not sure but it can be due to dust presence inside the SD card slot. Clean the dust inside the slot for detecting. Also try deleting cache. Go to library>cache>scroll all the way down and delete whats inside the bottom folder.
You can contact Apple Macbook Pro USA Technical support care number: (800–275-2273) for any help.

That would also be my first guess, followed my a damaged card reader… except for the fact that the Nintendo 3DS probably uses a different format than what Macs read natively. I don’t know enough about the 3DS to say for sure, but I doubt they use a normal computer format like NTFS (Windows) or ext2 (Linux), so it may just be a languag barrier.

Or are we talking the 3DS as in the file format used by Autodesk, a Windows-only program?

As an alternative you may be able to put the card in a camera or other device and use a USB cable to connect to your computer.

If you can see it in Disk Utility but the system doesn’t mount it, that’s probably because it’s using a file format not supported by Macintosh. From whence did these files come, and what device wrote them to the SD card?

If you can find out the device node of the card (i.e., by running `diskutil list` from Terminal) then you can use the `dd` command to make an image of the filesystem there. The syntax is `dd if=/dev/disk1 of=localfile` where /dev/disk1 is the node of the sdcard (/dev/something) and localfile is the path to the file you want to hold the image. You won’t be able to mount or do anything with the image right away (it’s like a picture of a filesystem, not the actual files) but you’ll have a backup copy which you can then copy to another device. You also can mount a disk image like this as if it were a device, but you need to have support for the filesystem involved first.

There’s also a GUI for dd available: http://www.gingerbeardman.com/dd-gui/

More information about `diskutil list` http://apple.stackexchange.com/questions/107953/list-all-devices-connected-lsblk-for-mac-os-x

I’m a Linux guy, so this is all based on my linux experience + internet research. Hope it helps.

What version of OS X are you using? OS X 10.6.5 and above, as I see it, can read exFAT, which the SD card may be formatted for.

I don’t know much about Nintendo stuff, but from what I gather it should be using one of the FAT file systems. It may even be FAT16, which I would hope OS X can read but I don’t know for sure. Assuming, of course, that you’re talking about Nintendo 3DS save files.

According to this if you go along with that the format is FAT16. The tool they suggest is what I use on my Mac to format the SD card on my Raspberry Pi. OS X has no problem reading or writing from it.

I would find a Windows machine and see if it works there before doing anything crazy.

to clarify, yes I’m talking about Nintendo 3DS.

For now I guess I’ll wait until I’m around a PC. I don’t think it’s the slot because I put in a blank SD card and it mounted fine. I’m using OS X 10.9

I’ll try @rexacoracofalipitorius advice. Well, I might leave that to my boyfriend since he knows Linux and stuffs. I’m a little afraid of terminal; I always think I’m going to eff something up lol

@rexacoracofalipitorius it says ‘dd: /dev/disk1: Permission denied’ when I try that

Yes, that’s a low-level device command, so you won’t be able to do it with normal user permissions. You will need to be logged in as root or use the sudo command.

You can verify this by doing `ls -l /dev/disk1` – that command should tell you who owns the file and what it’s permissions are.

Are you certain that /dev/disk1 is the correct device?

Except you don’t want to use dd or format until you get the data off, right?

@mrentropy The use of dd in this instance is meant to get the data off the sdcard and on an image file on the mac. The “if=” part of the dd parameters stands for ‘input file’, and the “of=” for ‘output file’.

@cutiepi92 DO NOT run that command the way I wrote it, I don’t have any way of knowing whether there’s a /dev/disk1 on your system or if it’s the right one. I don’t want you to try to copy your hard drive to itself!

@rexacoracofalipitorius I ran it the way you wrote it because when i ran the diskutil list, the sd card came up under /dev/disk1 exactly

when i entered what you said to verify who owns the file and permissions, it said ‘brw-r——- 1 root operator 1, 4 Jan 4 17:08 /dev/disk1’

Oh, good, I won’t worry that you’ve got the wrong device, then :^)

That line says that the file /dev/disk1 is owned by root, and that its owner has permission to read from and write to it, its group (operator) has permission to write to it, and no-one else has any permission to access it. Thus, you’ll need to be root in order to run the command.

I gave myself root permissions, made a new password and stuffs, but I’m still getting the same result. Wouldn’t it prompt for a password or something before denying me? What do I need to do?