It is not common for an iPhone to have problems that do not allow us to start the device and enter the home screen. But, as with any electronic device, it is possible, especially in times of scenes of the jailbreak or, more normal and current, testing the betas of the apple mobile operating system. 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 into DFU mode is a simple and safe process. If you search on the internet for how to do it, you will most likely find the method with several steps that involves 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. Furthermore, if we use the method that combines buttons and accounts we can also restart the device, which is not useful if what we want is simply restore our iPhone. Here we explain all the secrets of DFU mode.
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”, 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 you to upload /download version (as long as we have the SHSH saved to sign the firmware we want to install). We can also downgrade on an iPhone 4S or later as long as Apple continues to sign the version we intend to install.
On the other hand, it is possible 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
Until 2016, when Apple launched the first iPhone with a touch-sensitive home button that no longer depressed, everything was simpler. By this I do not mean that it is now more difficult to put iPhones in DFU mode, but that there are more models and each type is achieved in a different way. The most recent ones are not that they do not have a home button that does not sink, inaccessible if the software crashes; is that in 2017 came the iPhone X (ten) and the circle that until then had been something identifying for the block phone went away never to return.
What you have below is how to put iPhones in DFU mode separately by model, although there is part of the process that is repeated in all of them and is explained in the first three steps:
- We connect the iPhone with the cable to a Mac or a PC.
- We open Finder in recent versions of macOS or iTunes in older versions and Windows. It is possible that if you read this article after a few months or years, iTunes will also no longer be available on Windows and the application to use will be Apple devices. At the time of publishing this note, iTunes remains official for Windows.
- We turn off the iPhone.
What follows is what changes in each type of iPhone
iPhone with FaceID, iPhone 8/Plus and iPhone SE 2
- We press the power button for 3 seconds.
- Without stopping pressing the power button, press and hold the volume down button.
- We hold both buttons for 10 seconds. If we see the apple logo, it has gone wrong and we have to start over.
- We release the power button and continue holding the volume down button for another 5 seconds. In this case, what indicates that it has gone wrong and we have to start over is the message that invites us to connect the device to iTunes or Finder. If what we have seen is that the screen is still black, that's it. The computer will detect that the iPhone is in DFU.
iPhone 7/Plus
- We press the power button for 3 seconds.
- Without stopping pressing the power button, press and hold the start button.
- We hold both buttons for 10 seconds. If we see the apple logo, it has gone wrong and we have to start over.
- We release the power button and continue holding the volume down button for another 5 seconds. In this case, what indicates that it has gone wrong and we have to start over is the message to connect to iTunes or Finder. If what we have seen is that the screen is still black, that's it. The computer will detect that the iPhone is in DFU.
iPhone 6s/Plus and earlier
- 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.
The second method is better, right? The bad thing is that this method cannot work on phones without a sagging home button.
How to exit DFU mode
If you have put your device in DFU Mode without being necessary, you have a maximum of four options:
- Force a reboot, which until the iPhone 6s was with the sleep + home button, in the 7 and 8 with the off button + volume down and in those with FadeID it is volume up -> volume down -> off, and in all models keep until you see the apple.
- Options 2 and 3 are only for old equipment and are done with tools that are no longer available even on their official website. These are TinyUmbrella, with which you have to connect the device to the computer and tap the “Exit Recovery” button, and redsn0w, which we talk about later.
- Finally, if none of the previous options have worked for us, we can always restore, something that we will achieve by connecting our iPhone to a computer, opening Finder in recent versions of macOS and iTunes in older versions and in Windows and restoring from one of these options.
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 (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.
Conclusion
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 installed thanks to the jailbreak has left our iPhone/iPod or iPad in an infinite start in which it does not go beyond the apple logo that appears when turning it on.
