I dropped my phone in the toilet and I'm having the exact same problem and nothing has helped. My iphone has been through a lot and survived so i didn't think this would be a problem.......... It is!!! Unfortunately my power button broke earlier this week, my home button did this before and fixed it's self so i wasn't worried. But now I'm giving up it is seriously broken.............. Anyway try holding the power button and home button at the same time this has help me with other problems before. Give that a try if nothing works it's most likely broken.