1, shell
The shell of the new machine is tightly attached, and the gap is smooth and smooth without burr. Refurbishers generally use imitation original shell, with uneven gaps and burrs. The upper and lower parts of the mobile phone shell are easy to be closed loosely, leaving a large gap. When recognizing, you can try to insert a small nail into the gap between the upper and lower covers of the mobile phone. If it can be plugged in, it is a refurbished machine. The surface of the shell is frosted like a new machine, and the mobile phone with small particles is absolutely not to be purchased. The paint on the machine shell was sprayed by JS. After a long time, the paint will fall off (the dust particles on the shell are caused by the operation without vacuum environment when painting);
2.sim card
SIM card chip contact and battery contact. These two contacts are usually irreplaceable. If it is a refurbished machine, there will be obvious friction marks on the contacts of the SIM card chip, which looks shiny, which is caused by too much friction. If it is an unused chip of a new machine, the contact surface should be frosted;
3. Fixing screws
Mainly depends on whether there are obvious scratches at the interface between the screw and the blade, and whether there are pick marks on the two rubber pads below the inner screen.
4. Call quality
Bring your own SIM card to test the machine, call a friend, preferably a fixed phone, and ask the other party how the call quality is, whether the call sound is clear, whether there is noise, current sound and volume drop suddenly;
5. Software testing methods
The above detection methods are all routine practices, and the results may have some errors. In addition, there is a more successful and simpler method, which is to test with software. Download a mobile phone data recovery software on the mobile phone. If you can detect whether you have taken photos, strange contacts, short message records, short messages, etc. Through the software on your mobile phone, you can basically judge that the mobile phone is a translator.
There are two kinds of data recovery software recommended for you. One is the data recovery of domestic gecko, which is completely free and reliable. The other is the foreign Dr.Fone for Android, which has good software recovery ability, but the price is a bit expensive.