I took my phone out of my jacket today and sent a quick text, then went to the bathroom. When I came back, and hit the unlock button, the screen and buttons light up, but doesn't display anything (like the unlock bar, or the activate sound bar). The same holds true if I try to unlock it via opening the full slide-out keyboard. Plugging it in also doesn't work, and the LED on the side doesn't even come on to register that it's connected. I've never dropped the phone, or downloaded any questionable apps. Help? Suggestions? Much appreciated.