1. See if there are any insertion marks in common parts. Such as USB interface, earphone interface.
Generally, when the battery cover of a new mobile phone is opened, it smells like sandalwood and paint neutralization. This is because the engineering plastic of the mobile phone shell and the paint on the motherboard have not completely volatilized, and have not been corroded by enough air in the external space and the sweat smell on people, so this smell usually exists. But if you don't smell it, it doesn't mean it's a refurbished machine, or it may be a machine that has been in stock for a long time.
3. Check the light carefully when the screen of the mobile phone is black, and see if there are dust or scratches on the inner layer of the screen. If there is dust in the screen of any mobile phone (if only a few easily counted dust can be ignored), or there are traces of wiping, it can basically be concluded that the screen of this mobile phone was disassembled and reassembled after it appeared.
4. Look for traces of screwing on the assembly screw of the mobile phone (this is the most important point), and pay attention to the side groove of the head of the screw cup under strong light to see if there are traces of screwing with a screwdriver. Mobile phone screws are generally "blackened". "Blackening" is a kind of surface treatment of metal materials, not a piece of black live paint. If you screw the screw forcibly, you will generally find that the diamond edge of the screw groove will appear white and bright metallic color when you look at this bright surface.
People who haven't really made genuine mobile phones generally think that the assembly screws are screwed in. When you find that the screw has screw marks, JS will tell you, "How can I install the screw without screwing it in?" However, when regular mobile phone manufacturers assemble mobile phones, the screws are all punched in with cylinders. This involves a special fixture. Depending on the structure of the mobile phone, each mobile phone may have several different pneumatic tightening fixtures, and the investment is relatively large. Not to mention that the fixture material must be an expensive antistatic material, and the precision distance fixture processing of several guide holes requires a lot of money, and each mobile phone has several different fixtures. The special pneumatic tightening fixture is only used for factory assembly. But some renovation workshops absolutely do not have such conditions. In order to save cost and speed of decoration, it is inevitable to put a 5-yuan screwdriver on the site.
5. See if the film on the machine is original, that is, the kind with logo or various patterns printed on it (you can find it by looking up the picture of the mobile phone on Zhongguancun Quotes Online). If it is found that there is no film on the film, such a machine is very suspicious.
6. Check the fuselage shell and buttons. If there are obvious scratches or friction marks, you can't buy them.