Xperia Z wont boot

[Fookdook]

Yesterday I forgot my Xperia Z at my place before going out and when i came back, the phone ran out of power so I plugged it to the charger.  The LED at the corner is on but when I tried to turn it on, nothing happened.  I just left it alone for couple hours and try again, nothing happened in the first try, so I try it again and again ( sometimes the "SONY" appeared and the phone just shut down afterward ) .  It worked for some reason after many attempts but today i was running out of battery ( 7 percent ) so I turned it off.  I tried to boot it again after i plugged it in to the charger, but nothing happened again. 

Please help

Sorry for my bad Engish

[Uliwooly]

I had the same problem with my Xperia Z few days ago.

connect your xperia to a wall charger > press and hold power & volume up for 5 seconds > leave it charging for 1 hour even if you don't see any sign of charging > after one hour repair the phone with SUS 

install SUS > restart your PC > run SUS > follow the steps > connect your phone to the PC > press and hold power & volume up once the phone vibrates release both keys and only press and hold volume down

Don't forget to give Kudos

[Uliwooly]

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

PC Companion (PCC)

Bridge (for Mac)

Alternatives on How to backup Xperias

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

Don't forget the Kudos 

[Uliwooly]

If nothing works then you will have to take it to a Sony repair center

http://www.sonymobile.com/global-en/support/contact-us/

Don't forget the Kudos