The first thing you should look when you are buying second hand mobile is that the mobile does have any scratches or physical damage. The second and the important think that you should do is check whether the mobile is rooted or not. Those who doesn’t know what is root comment below and I will write a review on it. If the mobile is rooted the software of the mobile can get cracked anytime and the mobile will be useless. To check whether the mobile is rooted or not there are various types of apps available in playstore named root checker etc. Just download the app right away and check whether the mobile is rooted or not. After doing all this things you should check whether tha camera is working properly and the speakers. And always ask the seller to show you the bill so that you come to know that th mobile is genuinely buyed and not robbed from someone. Again check the mobile twice before you buy and then go for the mobile.