Sony Xperia Z locked screen, no internet connection, does not connect to computer
You gonna need to boot into recovery mod follow this steps


Switch off your Xperia Z first
Switch it back on and the time when you see your phone’s LED
notification light turn Pink! (or any other color) — start pressing
either the Volume UP or Volume Down key a couple of times to make
your phone boot into recovery mode
Once you’re in recovery mode. Use Volume buttons to navigate Up and
Down between options and Power button to select an option in
recovery.


navigate to the factory reset and click on power button.