I was using an application and suddenly the screen is turned off, while the back and home buttons were still lit, then it was off everything. Then I tried again to turn it on but there was no way. I tried to attack the charger but not the red LED is lit. I attacked the USB cable to the phone and then I connected it to the PC and gives me an error of no driver present (QHSUSB_DLOAD). What happened? What should I do?