Hi there, I have an iphone 6 and considering trading for a galaxy s6.
I am just wondering what should I look for to verify that I am not receiving a dud...i guess i should say to limit my chances of receiving a dud.
Are you "trading" with a friend? Or do you mean you want to trade in your phone to your carrier and get a new phone from them? If the latter, then don't worry about duds or anything else. Get the new phone, and if it works as it should, great. If not, bring it back and exchange for a new one.
My advice ... don't trade w/ a friend, and/or don't buy from anyone other than your carrier or an authorized dealer of the phone you want.