DFU mode in the iPhone follows similar steps as in the Mac devices. Step 1. Connect your iPhone to your computer using a USB cable and launch iTunes. Next, turn off your iPhone. Step 2. Next, hold your power button and home button simultaneously for 10 seconds. Afterward, release the power button but continue holding the home button until you get a message that your iPhone might be in Recovery mode. Click OK, and you will enter the DFU mode.