A small number of third-generation Apple TVs have known Wi-Fi issues, and Apple has started a replacement program for these affected units. Apple has determined replacements can be offered free of charge for up to two years after the device’s purchase date.
The Wi-Fi issues include: cannot locate network, unable to join network, and dropped or intermittent connection. If the last four letters of the serial number are DHRN, and the third and fourth characters of the serial number match one of the included pairs, the Apple TV is eligible for replacement. [via 9to5Mac]