1, Thunderbird official website inquiry: You can visit Thunderbird official website, find "Warranty Period and Rights Inquiry" in "Service and Support" or similar columns, and then enter the serial number (sn code) of the equipment for inquiry.

2. Check the fuselage number: You can check the label or number on Thunderbird TV. The fuselage number is usually the serial number of the machine when it leaves the factory, which can be used to query the relevant information of the equipment.

3. Customer service consultation: If the serial number cannot be found by the above methods, you can contact the customer service team of Thunderbird TV and provide them with relevant information, such as activation date and version, so that they can help find the serial number.