Xperia TL screen backout

[rrpchem]

My sony xperia TL-LT30 just backed out. I mean its not showing anything on the screen. I know it has full battery, was working fine. I tried power on/off. I can hear the sound of it turning on and off but nothing on the screen. Tried calling my number it rings but nothing on the screen. What shall I do. Please respond qucikly. Thanks for your help.

[Uliwooly]

Connect the phone to a wall charger > press and hold power & volume up for 5 seconds > let it charge for 1 or 2 hours > after 2 hours press and hold power & volume up until it vibrates

[rrpchem]

Battery is already full. I have tried volume up plus power several times. Nothing has been working out. Also, when I try conecting it to the PC companion it does not detect my phone. Something similar to these guys..

http://talk.sonymobile.com/t5/Xperia-S-SL-acro-S/Phone-menory-is-not-accessible-from-PC/td-p/214031

Please suggest something that would work. 

[Uliwooly]

You have to take it to a Sony repair center if its from AT&T then take it to an AT&T store