Apple last Thursday released Software Update 5.1.1 for second- and third-generation Apple TVs. In addition to stability and performance fixes, it also introduced support for the new “Up Next” feature found in iTunes 11. Unfortunately, a number of users are reporting problems with the update, resulting in aborted downloads and failures to reboot following an update attempt. Thankfully, TidBITS summarizes the solution: update over Wi-Fi.
Step 1: Unplug the Ethernet cable from your Apple TV.
Step 2: Connect to a Wi-Fi network using your Apple TV and attempt to update the device again.
Step 3: If the Apple TV is unable to boot, use a micro USB cable to connect it to a Mac or PC running iTunes (third-generation Apple TV owners also need to connect the Apple TV's power cord while it connected to the computer).
Step 4: Open iTunes and wait for the Apple TV to appear in the Devices section of your iTunes sidebar (for iTunes 10) or under your Devices button in the upper right portion of the window (for iTunes 11). Select the Apple TV from the list and choose "Restore."
Step 5: Wait for iTunes to download the restore firmware for your Apple TV and for the restore process to complete. Once completed, disconnect the Apple TV from the computer, reconnect it to your television, boot it up, and attempt to update again via a Wi-Fi connection.
The Mac Observer has followed up with several readers who performed the steps above and all reported that their device updated successfully. Thus far, it appears that only the update process is affected by the bug in the 5.1.1 software; after updating, users can reconnect their Apple TV to an Ethernet connection and content will be delivered normally.
For users who have yet to update, however, and who do not require immediate access to the “Up Next” feature, we recommend waiting to update until Apple releases a fix for the issue.