Look at the serial number
Each MAC has a unique serial number, which can be viewed by typing * # 06 #. Compare the IMEI number on the packaging box and the SIM card holder, and the three are the same.
Check the shell
The shell of the refurbished machine is often original, so it is necessary to carefully observe the seam and two screws of the front and rear shells to see if there are any traces of warping or opening. Businessmen often use detergents to make new machines, but the original equipment is more elaborate. If you look closely, you can find problems such as uneven painting.
Check the usage record
Games, text messages, phone books and other items have been used, indicating that there may be something wrong with the mobile phone. Frequent shutdown or crash also indicates that there is something wrong with the motherboard or software.
Pay attention to the price
Don't be greedy and cheap when buying a MAC. Find out the price of mobile phones online first. If it is too cheap, there may be problems. It is more reassuring to choose a regular store with good reputation and heavy service to buy a mobile phone.