Share your experience!
suddenly my phone's screen didn't respond anymore. the buttons and the applications are still working,
but you can do nothing when the screen is blocked!! what can I do now?
That seems strange, have you tried to do a repair of the phone software?
Click on this link to get Sony PC companion:
http://www.sonymobile.com/gb/tools/pc-companion/
Start PC companion, start "Support Zone", start "Update phone software" and click on "Repair".
Follow the on-screen instructions.
Let me know if you are still having this issue after the repair of the phone software.