When you update your system firmware version and boot the stock operating system, your Nintendo Switch burns a microscopic fuse to prevent your Switch from being able to downgrade. Essentially, if a stock firmware tries to boot but too many fuses are burnt for that specific firmware version, the system will simply power off, preventing you from booting.
All custom firmware bypasses these fuse checks and the fuse burns. By enabling AutoRCM you can prevent the stock bootloader from ever running and keep your Switch in a state where it can be downgraded again the future.
You can also use this guide as a way to upgrade your Switch if your Switch does not have access to the internet, uses 90DNS or is superbanned, and to downgrade your Switch to any firmware version.
If you want to prevent fuse burns you can follow this guide first.
If something goes wrong or you need help, check troubleshooting.
Step 1: Preparing Files¶
You need to locate the firmware binaries for the firmware version you want to upgrade/downgrade to. These cannot be shared here as they are copyrighted.
Make sure your SD card includes a basic Hekate/Atmosphere setup (such as the one installed when following this guide)
Insert your SD card into your PC
Create a new folder on the root of your SD card named “firmware”
Extract the contents of your firmware archive file into the new /firmware folder on your SD card
Step 2: Installing the New Firmware Version¶
Insert your SD card into your Switch
Launch Atmosphere CFW
IMPORTANT: Plug your Switch in to prevent the Switch from dying midway through the install process
Enter the Homebrew Menu through Album or title override
In Daybreak, select Install and enter the /firmware folder you created earlier
After processing, select Continue
If you are upgrading select Preserve settings. Otherwise, if you are downgrading, select Reset to factory settings, which will erase all save data.
Select Install (FAT32 + exFAT)
This “FAT32 + exFAT” version of the firmware contains both the FAT32 and exFAT filesystem drivers, so it will work with any SD card. If you are certain your SD card is FAT32 formatted, you can choose the option without exFAT instead. Choose the “FAT32 + exFAT” version if you are unsure.
Wait for the firmware update to finish
This can be take little time or a long time depending on the situation. Be patient, and don’t worry if it finishes very quickly.
After installation, select Reboot and then Shutdown Now!