Regarding this matter there isn't much that you can do. Try to turn OFF your device and remove the battery. Keep it like this for a few minutes then put it back in an try to start it up. While you are doing this, press and hold the Power button + the Volume Down until the android logo pops up on the screen. Use the Volume buttons to move through the menu and select using the Menu key : reset to defaults, try to clear the memory and clear cache. If the problem persists after you reboot your phone, I suggest you take it to a specialized service because it might be a hardware malfunction.
