DFU (Device Software Update) mode is not the same as recovery mode. Unlike the latter, it tests the current operating system that is installed on the device and allows you to update or rollback it. If you are getting error messages while trying to restore settings in iTunes, it is likely that it will help you. DFU (or Firmware Upgrade) allows all devices to be restored from any state.
As mentioned above, DFU is not a recovery mode that helps you connect to iTunes. In DFU, the iPhone screen backlight looks different and the display remains blank. If you have anything on the display, you are not in this mode.
The following is how to put iPhone into DFU mode. You can do this on every phone:
Connect your phone to PC and then turn it off. Press the Power and Home buttons, hold them simultaneously for 10 seconds. Then release Power but keep holding Home until the computer starts beeping, similar to a USB device recognition sound. If you managed to enable DFU mode on your iPhone, nothing should be displayed on the screen.
AroseProblems? Try changing 10 seconds to a slightly shorter time - 9 seconds, then 8, then 7. It's tricky, but you should be able to DFU your device.
Connect your phone to PC and set up synchronization. Then hold Home/Power until the phone turns off, within 10 seconds. If the phone keeps turning on during this phase, start over and hold the buttons for less time. Now release and keep holding Home until the computer recognizes the phone. It is believed that this method, how to enter the iPhone into DFU mode, may cause some errors. However, experts refute this point of view.
Connect your phone to PC and turn it off. Press and hold the power button. Keep holding Power. As soon as you see the image on the screen change, press Home. Then, continuing to follow the instructions on how to enter the iPhone into DFU mode, hold Power and Home simultaneously for 10 seconds.
Release Power but keep holding Home until the computer starts beeping. You will be able to see that you have entered this mode when the screen content changes noticeably.
The instruction on how to put an iPhone into DFU mode, as you can see above, has several methods, all of which are quite simple. However, it is important not only to correctly enter the device into this mode, but also to withdraw from it.
So, to exit DFU mode, just hold down the buttons at the same timeHome and Power until the Apple logo is displayed on the screen of the gadget.
It is also worth remembering that in Apple TV (2G) the connection of this mode is somewhat different. To do this, you need to connect your device to your computer using a MicroUSB cable.
Then you need to force the device to reboot by holding down the "Menu" and "Down" buttons at the same time, for six to seven seconds. Press Menu and Play at the same time immediately after the reboot, until a message appears in iTunes saying that the device has detected an Apple TV in recovery mode. You can exit this mode in almost the same way as in other devices.