Share your experience!
I can’t change the ear speaker volume during a call pressing the volume key up or down. Speakers volume is to high. What I should do to fix it? Thanks!
You can test your phone
https://play.google.com/store/apps/details?id=com.sonymobile.androidapp.functiontester
Thanks a lot for advice. When I test my phone everything is ok, but when I call I still can't turn down the speaker volume.
Repair your phone
Update Service (SUS)
http://www.sonymobile.com/gb/tools/update-service/
http://www-support-downloads.sonymobile.com/Software%20Downloads/Update_Service_Setup-2.11.12.5.exe
Bridge (for Mac)
Alternatives on How to backup Xperias
http://talk.sonymobile.com/thread/36355
Don't forget the Kudos
Thanks for help. Unfortunately everything gone worse. 
I tried update my phone with PC Companion. I strictly followed the instructions of the PCC. Phone battery was about 80% full. After repair my phone restarting - Sony logo flashing on screen. I waited almost half an hour and then noticed that my phone is dead, totally dead. Now phone doesn't response when I press button combination (power+volume up), doesn't charging from PC or wall... nothing, no charging light, no vibration, just black screen... dead.
I read in net that it is common problem with Xperia.
I hope tomorrow local warranty service helps me. I own this phone only couple days and I'm really upset and I'm not excited with my new Sony Xperia S LT26i. Too much problems in couple days and phone battery life is disaster.
Anyway I'll give message when I get to know what was wrong with phone.
Sorry for my ENG.
Uliwooly suggested you use the following to repair your phone, yet you use PCC.
http://www.sonymobile.com/in/tools/update-service/
Try to allow your PC to detech the phone using SUS and reinstall the firmware.
I suppose that Uliwooly advised me different ways how to update phone but result must be the same.
Anyway, as I say before, my phone is totally dead, nothing happen when I try to charging it from wall or connect to my PC – PC doesn’t recognize it.
But thanks for try to help! I really appreciate it!