It is not usual for an iPhone to have problems that do not allow us to start the device and enter the home screen but, as in any electronic device, it is possible, especially if we like jailbreak or try the betas of the mobile operating system of the Apple. When our iPhone is unable to start by itself, we will most likely have to restore the device, and the best way is to put it en DFU mode (Device Firmware Upgrade).
Putting an iOS device in DFU mode is a simple and safe process. If you search online how to do it, you will most likely find a method with several steps that implies having to count several seconds in each operation. That method is also included in this article, but whenever possible I recommend the second one, which is much simpler. In addition, if we use the "old" method we can also restart the device, which does not help us if what we want is simply restore our iPhone. Here we explain all the secrets of DFU mode.
Table of Contents
What is DFU mode for?
We could say that the DFU mode is a point 0 (or almost) in which we can restore an iOS device whatever the problem that we are experiencing. The main reason to use it is to change the firmware of the device. Although the "U" stands for "Upgrade", the DFU mode will also allow us to install a previous version of iOS, something that was especially interesting on the iPhone 4, a device with a hardware failure that will always allow upload / download version (as long as we have the SHSH saved to sign the firmware we want to install). We can also download the version on an iPhone 4S or later as long as Apple continues to sign the version that we intend to install.
There is also the possibility that our iPhone cannot be restored for some reason, so it is best to force DFU mode, which will allow us to restore our device.
How to put iPhone in DFU mode
We will do it by performing the following steps:
- We connect our device to the computer.
- We turn off the device.
- We press the power button for 3 seconds.
- Without releasing the power button, we press the start button (home) and the off button for 10 seconds.
- We release the power button and hold the home button until we see the iTunes logo with the cable on the screen of our device.
The previous method is the most popular, but there is also a much simpler way with only three steps:
- We turn off the iPhone.
- We connect the cable to the iPhone.
- With the start button pressed, we connect the other end of the cable to a computer.
Better the second method, right?
How to exit DFU mode
If you have put your device in DFU Mode without being necessary, you have four options:
- Force a reboot (sleep button + start until you see the apple).
- Although it is not exactly the same, we can downloadTinyUmbrella, connect our device to the computer and touch the "Exit Recovery" button.
- Finally, if none of the above options have worked for us, we can always restore, which we will do by connecting our iPhone to a computer, opening iTunes and restoring from the Apple media player.
- Use redsn0w (explained in the next point).
Related article:How to restore on iPhone in "recovery mode"
Can the iPhone be put into DFU mode without using buttons?
Yes. This will require let's use the redsn0w app. The process is very simple and we will achieve it by following these steps:
- We download the IPSW that we want to install on our iPhone.
- We download redsn0w. We may see a death dedication on the previous page. If that is the case, we can access older publications by scrolling to the bottom of the page.
- We open redsn0w. If we use Windows, we run it as Administrator.
- We click on the "Even more" option.
- Next we choose the option “DFU IPSW”.
- Now we choose the IPSW file that we downloaded in step 1.
- When the process of creating the special file for DFU mode is finished, redsn0w will notify us that it is available. At the time, we just have to tell you where the new IPSW file is, something that we will do with the usual method for when we want to install an IPSW file with iTunes: We open iTunes, connect the iPhone to the computer, choose our device from the upper left and We press Shift (on Windows) or Alt (on Mac) while clicking Restore.
- We look for the IPSW file that was created after step 6 and accept.
This is not exactly getting out of DFU mode, but since what we want is to restore the iPhone and at the end of the process we will have entered the home screen, for the case it is exactly the same.
What is the difference between DFU mode and recovery mode?
The main difference between recovery mode and DFU mode is startup. Recovery mode uses iBoot when restoring or updating an iPhone, while DFU mode does a ByPass to iBoot, which will allow us to download the version of our iPhone (if the previous iOS version is still signed).
iBoot is the bootloader of iOS devices. iBoot acts in restorations when the iPhone is in Recovery Mode and makes sure that we are using an iOS version equal to or higher than the one we have installed on our iPhone. If this is not the case, iBoot will not allow us to restore.
If we want to restore to the latest version, Recovery Mode will do almost everything for us, something that does not happen if what we want is to install a previous version of iOS.
Keep in mind that we do not have to put our iPhone / iPod or iPad in DFU mode unless it is strictly necessary. What is described in this article only makes sense if our device cannot be restored for some reason, as can happen when doing the downgrade from an iOS beta to an official version or because some tweak Cydia has left our iPhone / iPod or iPad in an infinite start in which it does not pass the apple logo that appears when you turn it on.