My Mt11i not work

[Loay1]

my MT11i when I open it (turn on ) it directly turn off ...before 15 days i made change in software for the same reson and it back to work.,,and know it's not work

[Uliwooly]

Repair it with SUS if that doesn't work, you will have to stop by a Sony repair center 

Update Service (SUS)

PC Companion (PCC)

Bridge (for Mac)

Alternatives on How to backup Xperias

http://talk.sonymobile.com/thread/36355