Ever since I got the 3DS the Sd card has very finiky, sometimes it works most of the time it says the SD card cannot be read. It even cuts out in the middle of games on the card. I would just like to ask anyone if they know what's going on, seems like a bad connection between the copper contacts or the SD card reader in the system itself is defective. I know it's not the SD card as I have tested several in the system, and the SD card works in my other devices. If anyone knows please comment, thanks.
The 3DS is obviously having some trouble reading SD Cards, and there isn't anything that you can do on your own to stop this from happening.
A repair from Nintendo would solve this, however. The warranty lasts one year, and can be extended by 90 days if your register the 3DS with Club Nintendo. You can schedule one by calling 1800-255-3700 (6am-7pm, Pacific Time, 7 days a week).
Just a suggestion, this happened to me with game cartridges in my old Gameboy. Try taking out the SD card and blowing inside the slot and se if it works
Sorry, but blowing into any of your video games, consoles and or handhelds is probably one of the worst things you can do, as the moisture from your breath, or even saliva can enter them and cause corrosion and even worse problems then what you are attempting to fix by using this method.
And if you do not believe there is any moisture in your breathe, just stand in front of a mirror and blow on it and watch the mirror begin to slightly fog up and that exact same thing is what takes place inside your video games, consoles or handhelds when you blow in them too.
Well yeah I suppose that makes sense... the reason why I even said that and believe in the idea is because this is hwta my sister had ALWAYS told me to do. now that I actually use my mind I wont do that anymore.