1. With or without iCloud Activation Lock

When buying a second-hand iPhone, you should check whether the iPhone has iCloud Activation Lock through Apple's official website. If there is an activation lock, firstly, it is impossible to confirm whether the seller is the owner, and secondly, the iPhone may be directly locked remotely and completely unusable in the next day, second hand iphone  ， so it is very important to check whether there is an activation lock iColud Activation Lock.

2. DFU mode flashes

Although checking the serial number of the iPhone can identify the true and false, but check the activation date, warranty date and other information. However, the serial number is determined by the motherboard. Some scammers on the market may tamper with the serial number, so if you are strict, you can also identify it by flashing the DFU mode.

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