i've always learned to check for the white paint on the nokia lettering on the face of the device.. Sometimes I go a bit further, open it up and see if there are any Silver screws, or Chinese parts.. I've bought a Chinese nokia n900 by accident once.. It came in a Lumia case with none of the original packaging. The original seller was claiming that it was new.. It had all of the listed problems. Always buy within the country you live in and never buy anything from China or it's surrounding countries. Not trying to be prejudice against the fine and wonderful people of China, but there is a lot of bootlegging that goes on there.