Earlier today, i was using my samsung brightside to text, and i noticed that the power/end button would only work if the screen was slid out. And then the back button started to not work as well. And now, about 10 minutes ago, when i unplugged my phone from the charger and opened it up, all there was was a white screen. I continue to try and turn it on using the power/end button, but it seems to not be working at all. Please help.