When is it recommended to put an iPhone 11 into DFU mode to overcome Error 80, and what are the steps to do so?

DFU (Device Firmware Update) mode is recommended when standard recovery mode or general troubleshooting fails to resolve Error 80, as it performs a deeper restore of both software and firmware. To enter DFU mode on an iPhone 11: Connect to your computer. Quickly press and release Volume Up, then Volume Down. Press and hold the Side button until the screen goes black. Once black, immediately press and hold Volume Down along with the Side button for 5 seconds. Release the Side button but continue holding Volume Down for another 5-10 seconds. Your computer should detect an iPhone in recovery mode, but the iPhone screen will remain black.