DFU mode is a special state where your iDevice can do interface with iTunes but does not load the iPhone operating system or boot loader. DFU stands for Device Firmware Update. Main benefit of entering in to DFU mode is to change the firmware on the device. This can serve to downgrade to a prior firmware and operating system, or to use a custom firmware that is required for a jailbreak.
Instructions to enter in DFU Mode ATV:
- Plugin your Apple TV with microUSB.
- Hold menu + down button together for 6 secs to reboot.
- Once your Apple TV reboots immediately hold menu + play together until a message appears in iTunes telling you an Apple TV in recovery mode has been detected.