Hi, I have a Samsung Galaxy S2 HD LTE phone, between 1.5 - 2 years old. I picked it up, pressed the side/unlock screen button, and the screen remained black, however the bottom 4 buttons glowed, and the backlight for those buttons would not go off unless I pressed the side button again. I tried pressing the side button a couple of times, and the same thing would happen, black screen, glowing buttons at the bottom of my phone. I then tried holding down the side button to restart my phone. I'm not positive, but it seems to take longer than usual to restart. The only reason I know it is restarting, is because my phone does a small vibrate when it has restarted. The screen has remained black, nothing has appeared on it since the issue started...including the 'Samsung' symbol (etc.) that usually appears when I restart my phone. My phone had probably somewhere around 50%+ when this happened, so it can't have just run out of batteries, especially since it is still vibrating when I restart it. I tried plugging it in to my normal charger, and nothing happened, it didn't even do a subtle vibrate to tell me it is charging. What could be the issue? Thanks!