my nokia lumia 720 is almost 6 months old....today i accidently switched off my ohone when i recieved an sms,when i tried to restart it,the screen got stuck with the nokia symbol,i tried the volume down+power button reset,but since the volume down button is not working like most lumia 720s.....it is stuck at the nokia symbol screen....plzz,need help,anyone can give me a solution?????thnx