Part one: How to enter DFU mode
Step 1. Connect your iPhone to the computer and run iTunes.
Step 2. Turn off your iPhone.
Step 3. Keep pressing the "Power" and "Home" button at the same time for about 15 seconds
Step 4. Release the "Power" button and keep holding down the "home" button until iTunes detect your iPhone entered the recovery mode. Then your iPhone is in DFU mode. The screen of iPhone will be totally black in DFU mode.
Part two: How to exit DFU mode
To exit DFU mode, press the "Power" and "Home" button at the same time until Apple logo appears. Then turn on your iPhone as usual.
Part three: How to retrieve deleted data from iOS device
Step 1. First of all, download iPhone Data Recovery software on your computer, then run the program.
Step 2. Connect your iPhone 6 Plus/6/5s/5/4S, iPad or iPod touch to the computer. Then the program will automatically detect your iDevice. Just click the button "Start Scan".
Step 3. After a few minutes for scanning, all found data on your iOS Devices will be displayed on the interface. You can preview the data and check them in detail. Then choose the item you desire and click the button "Recover" to save them to your computer by default. And you can also recover text messages, iMessages, contacts or notes to your iDevice directly.
With iPhone Data Recovery program, you don't need to worry about data loss due to entering DFU mode. You can easily recover lost or deleted data from iOS device by utilizing it.