yes I sent them back to china and they all returned fixed, no idea what they did though. I returned them to their original owners and they all promised never to update again lol, I don't blame them. it is very strange that this is happening to some units only. I suggest to buy only from authorized dealers in your country if possible, if something like this should happen the returned time could be minimum or even avoided completely by buying known genuine units. there has to be a way to fix this things without having to send them back for sure, they just not telling us, maybe for security reasons, no idea.