This method should be used if you plan to maintain the system that you have. If you no longer have access to your switch system, for example, if you sell it or give it to someone, you can use a full initialization process to delete all your user data and information. The initialization is carried out in the Mode Maintenance, which is not accessible if the console is switched on or in sleep mode. Following this steps to initialize Nintendo switches without deleting the save data:
Initialize Console Without Deleting Save Data
- If the console does not respond, hold the POWER button for twelve seconds to force to close.
2. With the console powered off, press and hold down the volume goes up (+) volume down (-), and then press the POWER button to turn on the system.
- Continue to hold down the volume button until Maintenance Mode menu to appear.
3. Once in Maintenance Mode, select "Initialize Console Without Delete Save Data. "
If the parental control PIN has been set for the system, you will be prompted to enter it to continue.
Read How to Set Up or Adjust Nintendo Switch Parental Controls