DFU mode is used when iTunes cannot detect i-device. This could be caused by damaged firmware. DFU mode refers to recovery modes of operation, just like Recovery mode.
Instructions
Step 1
Both recovery modes of operation of i-devices - Recovery and DFU - are used for flashing devices. The difference lies in the degree of aggressiveness of these modes - in Recovery mode, the device can be flashed through the iTunes application using the.ipsw file, and DFU mode means turning on the device without starting the iOS operating system. Please note that Apple recommends using Recovery mode and, only if you cannot perform the necessary actions in this mode, switch to DFU mode.
Step 2
Therefore, try first to perform the necessary operations in Recovery mode. To do this, simultaneously press the Power buttons on the top of the device and Home on the front screen. Wait until the "Shutdown" slider appears on the screen and the image disappears. After that, the screen will be filled with thin white lines. Don't let go of the Power and Home buttons! Wait for the iTunes application logo and the connecting cable to appear on the screen of the mobile device and release the buttons.
Step 3
Connect your device to your computer and launch iTunes. Confirm the check for firmware updates by clicking the Check Now button and the device goes into recovery mode. Use the Shift key and click the Restore button. Specify the required firmware file in the dialog box that opens and wait for the process to complete.
Step 4
Quit the iTunes application to put the device in DFU mode. Connect your mobile device to your computer with a USB cable and turn off the device. To do this, press the Power button and hold it until the Power Off slider appears. Drag the slider to the right and wait until the gear symbol disappears from the screen.
Step 5
Press and hold the Power and Home buttons for ten seconds, then release the Power button. Keep the Home button pressed until the computer detects the device as a "new device". Launch the iTunes app and follow the steps required.
Step 6
Please note that the device screen remains completely black in DFU mode. There are no external manifestations of the DFU regime!
