A colleague of mine had her iPhone crap out on here a few days ago, wouldn't respond or turn on. I tried a hard reset which worked. However she had the same problem this morning. A hard reset doesn't work. The strange thing is I plugged the phone in my PC and it appeared in Explorer showing the phone as an external drive, which I presume it would not do while the phone is off? We have tried ringing it, it does ring but the phone doesn't make any sound, light or vibrations (could be on silent). So my best guess is the screen? Could it be anything else? Any suggestions we could do before taking it further?