If basic fixes for a failed Switch system update don’t work, try advanced steps. First, perform a factory reset (without deleting save data): go to 'System Settings' > 'System' > 'Formatting Options' > 'Initialize Console Without Deleting Save Data'. This resets system settings but keeps your games and progress. If the update still fails, use a PC to download the update manually from Nintendo’s support website. Create a folder named 'switch' on a microSD card, then a subfolder named 'update'. Place the downloaded update file in the 'update' folder, insert the card into the Switch, and hold the power, volume up, and volume down buttons to enter Maintenance Mode. Select 'Apply System Update' and follow prompts. If all else fails, contact Nintendo Support for hardware repair.