If a custom keyboard is installed and custom firmware is removed from the console, System Settings will be inaccessible and you will not be able to launch the keyboard. This is obviously detrimental to the overall functioning of your 3DS and should be fixed as soon as possible.
There are other ways to reinstall custom firmware on such a console, but they may require additional hardware. This guide aims to reinstall custom firmware without any additional hardware, but if you have the means, ntrboot will probably be less of a pain.
Unbricking a 3DS with a custom keyboard installed
If Internet access isn't currently set up, you can set up an Internet connection from Safe Mode as the keyboard will still work there (hold L+R+↑+A on boot, then follow its prompts).
Methods that don't require seedminer
The following methods do not require seedminer and can be followed like normal:
Your NAND backup (e.g. 220101_AA000000000_sysnand_000.bin)
essentials.exefs
movable.sed
YOU DO NOT NEED TO MINE YOUR SEED AGAIN.
For instructions on extracting your movable.sed from your NAND backup or from essentials.exefs, see this page.
Section I: Installing Pokémon Picross
If the eShop requires you to use the keyboard, or you cannot install Pokémon Picross, there's no point following the rest of this guide and you should choose another method.
Follow these steps to redownload Pokémon Picross if available
Section II: Mii mining
If you already have your movable.sed, you can skip this section.
Because you can't enter a friend code due to the broken keyboard, you'll need to get your console's encryption key a different way. We can accomplish this by Mii mining.
Follow Mii mining to extract the movable.sed from your console, but do not continue onto the main guide as it suggests. Come back to this page once you have the movable.
If the eShop requires you to use the keyboard, or you cannot install Steel Diver: Sub Wars, there's no point following the rest of this guide and you should choose another method.
Follow these steps to redownload Steel Diver: Sub Wars if available
Section II: Mii mining
If you already have your movable.sed, you can skip this section.
Because you can't enter a friend code due to the broken keyboard, you'll need to get your console's encryption key a different way. We can accomplish this by Mii mining.
Follow Mii mining to extract the movable.sed from your console, but do not continue onto the main guide as it suggests. Come back to this page once you have the movable.
If the eShop requires you to use the keyboard, or you cannot install Mario Kart 7 or its 1.2 update, there's no point following the rest of this guide and you should choose another method.
If you have a cartridge of Mario Kart 7 and it's the same region as your console, you can skip this section.
Follow these steps to redownload Mario Kart 7 if available
If you already have your movable.sed, you can skip this section.
Because you can't enter a friend code due to the broken keyboard, you'll need to get your console's encryption key a different way. We can accomplish this by Mii mining.
Follow Mii mining to extract the movable.sed from your console, but do not continue onto the main guide as it suggests. Come back to this page once you have the movable.