So I was driving and decided that I needed to make a phone call. My Hyundai Sonata 2012 had a bluetooth feature that I have taken advantage of from the moment I bought the vehicle. After I was finished with the call, I pressed the "End Call" button on my steering wheel. All seemed normal, until I attempted to make another call using the bluetooth feature. The car indicated that the phone was in use in normal mode (ie without using the car's bluetooth system) and needed to complete that phone call before proceeding. So I checked my phone and to my surprise, the screen was black (as if it was off) and the phone completely unresponsive. It doesn't seem to be responding to my attempts to turn it on. I have not tried putting it into DFU mode, however, it doesn't seem to be responding to the use of the buttons whatsoever, so I'm not entirely sure I will be able to enter the phone into the mode itself. Slowly learning how inconvenient it is for me to be without my 4. Any ideas are greatly appreciated! (I have a Genius Bar appointment for 2:30 p.m. tomorrow).