DFU Mode is also called as the Device Firmware Update mode where the user can get their device connected to the iTunes with any internal processes possible through it, but the actual operating system is not booted up. This is not similar to the Recovery mode, and you usually would use the DFU mode when you are trying to do a firmware update of the device or are facing any troubles with the iOS and wanted to restore it through the iTunes. The DFU mode would bypass the current iOS and let you do something directly from the iTunes.
How to Enter DFU Mode
There are different ways to enter into the Device Firmware Update mode, and they are listed below based on the way:
Enter DFU Mode by Turning off iPhone
- Connect the phone to the PC using the USB Cable
- Turn the phone off manually
- Hold the power key and the home key together for *exactly* 10 seconds
- Release the power key but keep holding home until the PC tells that a USB device is recognized.
- Do keep a check on the iPhone screen, as it should not turn on during this process. If it does, then you haven’t entered into the DFU mode properly.
Enter DFU initially by Turning On
- While the phone is powered on, connect it to the PC with the USB cable
- Turn the Phone Off
- Now, just hold the Lock / Power key initially until you see something on the screen, even the initial apple logo. Now press home
- key while keeping the Lock / power key pressed.
- The screen would go blank again, and this is when you need to hold the home key for 10 seconds, and then release it to see the
- computer flashing the message about the device detected.
You mainly need to be careful and precise about the timing here, as holding the home key for more than 10 seconds could bring out a different result and also the iPhone may start, thus you would need to repeat the entire Device Firmware Update process, though sometimes doing it a couple seconds less can do the trick. If you are doing it totally wrong, there are a few errors that could be shown by iTunes, one of the most commonly seen ones is 1604 error.
While you Enable DFU mode, you cannot carry out anything on the iPhone, but the entire process during this time would be done only through iTunes on your computer.