When ever you find a second hand mobile always check the company seal of the device whether it is opened or not if by any chance company seal is not there so keep in mind that the device has been opened for some hardware issue , second thing make a call on the device you are buying check whether it rings and talk to somebody to check its speaker and mic , after that check for the volume and power button whether they work well , then open the back of the mobile and check for the battery is the battery swollen , after that open camera check the focus click some pictures , check the headphone and charging point jacks , use internet over it because sometimes 3G signals gets weaker over a second hand mobile , play music , use the device hard for 20 mins and check whether the device heats , check for the sim card and memory card slots , and ask for the original charger for the device
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