I have a iPhone 4s and it was working perfectly fine before, i went to sleep and put my phone on the desk. When i woke up i tried to turn on my phone but nothing happened, i pressed all the buttons and tried the sleep/wake method where you hold the home and lock button at the same time, then i decided to charge it, it's been charging for around an hour now and the screen is still black and there's no sign that it will turn on, i gave up up and tried connecting to itunes through my mac, it said the usb was using up too much energy and didn't connect. I'm desperately running out of ideas and i don't know whether it's broken or not
Added (1). please answer!