The power button on my phone doesn't do anything. It was fine, then a minute later, it just stopped working. The button is fully intact, and presses in and everything. It just doesn't lock/unlock the screen, and I can't use it to turn the phone on or off. It simply doesn't register the button press. Does anyone know of a way to fix this? I don't know much about the phone, I just use it, so I have no idea what would cause this.