apple tv 3 con serial defectuoso

Thank you for that link. The replacement program seems to be about the A1427 model (March 2012–March 2013), and matching replacements could be offered for up to two years after the device’s purchase date. I suppose that meant that a proof of purchase/registration was needed. That replacement program has ended 4 years ago, though.

Apple TV (3rd generation) is almost 7 years old, and has been discontinued for 2.5 years. If anything is broken, it won’t be repaired, and they will suggest that you buy a new model. Perhaps the issue is not on the device, though.

What/where does it mention a defect? Or is that your assessment? What does a serial number have to do with it?

If the AirPlay/Home Sharing connection has intermittent issues, then you should focus on the issue with your network and Wi-Fi. There may be interferecene, or the signal strength may be inadequate, or the unit is not in a spot with good enough reception.