Just received a (previously used) Mi2s. Phone seems fine, except the camera focus does not seem to work at all. Tried all the different settings for the focus (auto, standard, macro, ...) - this does absolutely NOTHING. Phone is up to date with the latest auto-update for Miui. This focus problem is also evident in other apps, e.g. google goggles and barcode readers. Because of the lack of focus, it is impossible to read barcodes. Any suggestions how I can find out whether this is a hardware or software problem?