The DFU mode, or Device firmware update, can be used to update the firmware of your iPhone, completely restoring the software. It is ideal when your iPhone does not cooperate and does not respond.
You will want to update the firmware of the device if the standard restoration using the recovery mode does not work for you. A DFU is a last resort.
What is the firmware?
The firmware is a software located between the hardware, your iPhone and the software, which corresponds to the iOS operating system. The firmware is used to provide various functions at the hardware level. This is the firmware that starts the iOS software when you turn on your iPhone. Therefore, if you are trying to update or restore the firmware, it may be useful to repair an unresponsive iPhone.
Steps to put your iPhone in DFU mode
Step 1: Connect your iPhone to your computer with the USB cable and make sure that iTunes is running on your computer.
Step 2: At the same time, press and hold the start button and the on/off button. Keep them together for exactly 10 seconds.
Step 3: After 10 seconds, release the sleep/wake button while holding down the Start button for another 10 seconds.
Step 4: Do not release the start button until iTunes displays a message that an iPhone has detected in recovery mode. The screen of your iPhone must remain completely black. NOTE: If you see the Apple logo on your screen, keep the buttons pressed for too long. Keep trying until the iTunes message appears.
Step 5: Your iPhone will now appear in the “Devices” of your iTunes account. Click on the “Restore iPhone” button.
How to exit DFU mode
Simply press and hold the start button and the on/off button simultaneously until the Apple logo appears.
Q: What does DFU stand for?
A: Update the device firmware.
Q: What is DFU Mode?
A: The DFU mode is a state in which you can place your iPhone where you can interact with iTunes but it does not load the operating system of the iPhone.