Device Firmware Update, or DFU, is one of two possible recovery modes for iOS mobile devices. In this case, the operating system is not loaded, and the connection to the computer is only needed to transfer technical information.
Instructions
Step 1
DFU mode differs from Recovery Mode in that it allows you to directly flash a mobile device running iOS. This method may be necessary if it is impossible to unlock the device or if you are unable to perform the flashing procedure in a milder Recovery Mode.
Step 2
Follow the official instructions provided by Apple to put your mobile device into Devuce Firmware Update mode. To do this, first of all, close the iTunes application and connect your device to the computer using the special connecting cable included in the package. After that, turn off your mobile device using the standard method, i.e. press and hold the Power button located at the top of the device. Wait for the slider with the inscription "Turn off" to appear and drag it from left to right to confirm the execution of the selected action.
Step 3
Press and hold the Power and Home buttons at the same time for ten seconds. Then release the Power button while continuing to hold the Home button. Wait until your computer detects your device as a new USB device. This usually takes no more than ten to fifteen seconds. Please note that no icons or inscriptions will be displayed on the device screen. There are two options for the appearance of the device in DFU mode - completely black or completely white. Both options are the only indicator of the active DFU mode.
Step 4
Wait for the iTunes application to detect the device in DFU mode and perform the necessary flash and restore operations. If you want to exit DFU mode, simply press and hold the Power and Home buttons at the same time until the Apple logo appears.
