Open KINDLE, Settings-Device Options-Device Information, find the serial number, open the Amazon website, click Customer Service, send the serial number to customer service, and ask customer service to query the serial number information to know whether it is authentic. The serial number of each device is unique.

When buying a mobile phone, check whether the games, text messages, phone books, call records, self-compiled ringtones and other items in the mobile phone have been used. If so, there is a very high suspicion of refurbishment. In addition, during normal use, the machine frequently shuts down or freezes automatically, then it can be said with certainty that there are certain problems with the motherboard or software of this phone. As the saying goes, it is a big loss to be greedy for small profits. It is recommended to buy mobile phones from regular sales stores with good reputation and emphasis on service.