Hello, i have a problem with the phone. The last days, when I received calls the phone would stuck and reboot itself.Sometimes it booted successfully,others it failed. Now,when I power it up, the screen lights up but it doesn't show anything else, and the phone does not boot. I tried pressing home+power to reset the device to factory settings but the Warning icon does not appear. Also I tried a different battery but the problem remains Any ideas what to try?