NOTE: While putting your device into DFU Mode is often required for some situations, it's important to remember that downgrading your OS or jailbreaking your device can damage it and put it out of warranty. If your plan to use DFU Mode, you're doing so at your own risk and are assuming the responsibility for any adverse results.
What Is iPhone DFU Mode?
The iPhone DFU Mode is a mode you can put your iPhone, or other iOS device, into that allows you to make very low level modifications to the software running the device. While it is related to Recovery Mode, it's more comprehensive.
When an iOS device is in DFU mode, the device is powered on, but hasn't yet booted up the operating system. As a result, you can make changes to the operating system itself that you wouldn't otherwise be able to.
What Does It Stand For?
Device Firmware Update.
What Devices Does It Work On?
DFU Mode works on:
When to Use iPhone DFU Mode
For almost all normal uses of the iPhone, iPod touch, or iPad, recovery mode is the only mode of this kind you'll need. If your device is stuck in an update loop or has data so corrupted that it won't run properly, recovery mode is your first step. Most people use iPhone DFU Mode to:
- Downgrade the firmware/version of the iOS running on the device. You might want to do this if, for some reason, an upgrade to a newer version has damaged your device or caused your apps not to work properly.
- Jailbreak the device.
How to Enter DFU Mode
Putting a device into DFU mode is similar to recovery mode, but not quite as easy. It took me at least half a dozen tries to get the hang of it, so don't be discouraged if you can't make it work right away. Most likely your problem is coming during step 4. That was the source of my difficulty, but once I learned to be more patient, everything worked fine.
- Begin by connecting your iPhone or other iOS device to your computer.
- Turn off the device by holding down the sleep/power button in the top right corner and the Home button on the front button of the device at the same time. A red slider will appear. Slide it to the right to turn off the device. Alternatively, keep holding both buttons even after the slider appears and the device will turn off. Let go of the buttons when the device powers down.
- With the device off, once again hold down the sleep/power and Home buttons at the same time.
- Hold these buttons for 10 seconds. This is the crucial step. Be patient and slow with your count. If you count too quickly and let go before 10 full seconds have passed, you'll enter recovery mode instead of DFU mode.
- After 10 seconds have passed, let go of the sleep/power button, but keep holding the Home Button.
- The Apple logo will appear on the device's screen, but keep holding the Home button until the recovery mode warning pops up in iTunes. Then you can let go of the Home button.
- If your device's screen is black, you're in DFU Mode. It may appear that the device is turned off, but it's not.
- If you're in recovery mode (indicated by a graphic of a cable connecting to the iTunes icon) or have booted up your device, repeat these steps.
Other means to enter DFU Mode include non-iTunes software tools.
How to Exit It
To exit iPhone DFU Mode, you can just turn off the device. Do this by holding down the sleep/power and Home buttons until the slider appears or, if you hold it longer, the device turns off and the screen goes dark.
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