The screen of my iPhone won't turn on but the touch is still responsive

I went to sleep with my iPhone 4s next to me. When I woke up my phone would not cut on. Siri still works and I can still unlock my phone but the screen won't cut on. The touch is still on though because I can put my pass code in and unlock my phone. I've already tried holing down the home button and power button AND charging it. Neither of them worked.