Here is a guide on how and when to use DFU mode to restore your iPhone or iPad.
When we are using our iOS systems on newer versions or even jailbroken versions, there are often things that can go awry and we may end up with a frozen or apparently bricked phone.
The best way to quickly attempt to restore the unit back to its original settings is by using DFU mode.
How to Use DFU Mode to Restore Your iPhone
Here are the steps to take if you need to restore your iPhone with DFU mode.
How to Enter DFU Mode
In order for you to restore your iPhone with DFU, you will need to have its USB cable plugged into your computer with iTunes open and ready to use. Using two hands, perform a hard reset on the device until the screen goes black (Home and Sleep/Wake for about 5-7 Seconds). When the screen goes black, release the Sleep/Wake switch and only hold the Home button.
You should know that the device has successfully entered DFU mode when an alert from iTunes pops up stating that it has detected a device in recovery mode and will ask you to restore it. Click Restore in order to attempt to resurrect your device and allow iTunes to download (if needed) and update your software back to the latest supported version.
The fact that you are able to get your iPhone into DFU mode however, does not indicate that it will successfully restore. This is a great first step to getting your iPhone back up and running yet if there is damage to the firmware or a hardware issue, the device may not simps restore.
Allow iTunes to go through the process and note any error codes that are triggered if it fails. There are thousands of error codes yet different categories of numbers will indicate what kind of failure you are experiencing. It is impossible to list all of the error codes yet searching the Apple Support website with the given code you receive will usually yield some answers as to your problem being software or hardware related.
If you did not receive an error code and the iPhone reboots successfully after the restore, you should be in good shape to get your iPhone working again by counting the setup process on your device when you see the Welcome screen.
DFU mode differs slightly from standard recovery mode as recovery mode is usually used by the iOS to perform standard upgrades to the OS and appears as an iPhone in iTunes. DFU mode will not load the firmware and iOS version automatically and therefor if you are looking to use another iOS package to jailbreak your device, this is the preferred way of restoring an iOS build back to your Phone.
Knowing how to use DFU mode is a great resource if you are having problems with your iPhone software consistently misbehaving or would like to test a jailbreak build. It is not necessary to use DFU mode for every restore that you perform, especially if you are just planning on upgrading the device, yet it is still a great piece of knowledge to have when it comes to knowing your iPhone and iOS.