There are a lot of miners out there now that are 'new' from places that are doing really nice refurbs and unless you really look close or know what to look at it's tough to tell that they are not fresh out of the box
I just got an L7 from a person who refurbished it and it's sitting in a rack mining, but when I took it out of the box it looked like it just rolled out of the factory. No dust, no dirt, all fans perfect, all boards washed, and so on. Just some discoloration here and there and that fact that I knew it was a well done refurb were the only reasons I would not have said new from Bitmain.
-Dave