Apple TV enhances your viewing experience, from mirroring your iPhone or iPad to displaying photo galleries on the big screen. However, when updates or restores fail, entering recovery mode (also known as DFU or Device Firmware Update mode) is often the solution. In this mode, Apple TV connects directly with iTunes to update or modify firmware without loading user-facing components. You'll need a Micro-USB cable to connect it to your Mac or PC.
Grab your Micro-USB cable and connect one end to the Apple TV and the other to your computer's USB port.
Note: Apple TV doesn't require HDMI connection to your TV or power outlet for this process. While you can keep it connected to your TV, disconnecting other cables simplifies things.
Launch iTunes (it may open automatically). Your Apple TV will appear in the device list. Restart it using the remote: press and hold Menu and Down for about 5 seconds, then release. The device will disappear from iTunes.
Once restarted, immediately press and hold Menu and Play/Pause for another 5 seconds to enter recovery mode (DFU). The Apple TV reappears in iTunes.

iTunes will detect the Apple TV in recovery mode, offering options to eject or restore it to resolve issues.
If you're just testing, you've succeeded—no further steps needed. But for troubleshooting, select Restore Apple TV while connected.
A warning will confirm that this erases all media and data, then installs the latest software automatically.

Click Restore and Update. The process takes a few minutes. Once complete, Apple TV exits recovery mode.
If needed, eject safely from iTunes before disconnecting, then reconnect as your TV set-top box for normal use.