bought a 7c from s and d (it said it was fine/no damage)
when i first got it the right alieron (when moved alieron stick right) didnt work
i opened it up and tightened all the screws by the gimble and it has worked fine ever since
one of the connections was loose
if you were to have a problem u couldnt fix, and s and d sait it was fine/no damage i would bet money that tower would replace it