All game carts contain a copy of the required system version to play it, allowing anyone on a lower version to use the cartridge to update to that version (even without an internet connection).
Note that Cart Updates will only deliver updates to core features, such as the System Settings, Home Menu, etc. Cart Updates will not deliver updates to Nintendo 3DS Sound and Network features, such as System Transfer, Internet Browser, StreetPass Mii Plaza, or eShop.
This means that using a Cart Update from a version containing an older Nintendo 3DS Sound version (<3.0.0) to one that introduced a newer Nintendo 3DS Sound version will break Soundhax! You will need an alternate method of entering the Homebrew Launcher!
This also means that a cart update will NOT install a browser if you do not already have one. This will only update the actual system version (for example, 2.1.0-0 -> 6.0.0-0). The last number (the -0) will not change.
Updating with a game cart containing the version 9.9.0 or above will remove your browser until a standard online update is performed!
What you need
- A game cart that contains the version you wish to update to
- Boot your device into recovery mode by holding (L) + (R) + (A) + (UP) while powering on
- If prompted, decline the update
- Reboot your device
- Put the game in your device if it is not already
- Attempt to launch the game
- Update when prompted