I have the same problem for few months and already gave it up until last week when I was trying to throw it away. I made a final attempt. What I did was push the power button on, off, on, of ... repeatedly (the lens shutter open and close repeatedly). All of a sudden the black screen disappeared. After that I tried many times and finally figured out he trick :
1 press power button and release the button,wait for 1 second,
2, then repeatedly press the power button 4 times quickly, you will see the black screen disappear. The active live display will appear in the screen, you can take the picture normally.
You night have to try to adjust the timing of each click. Make it 1 long click, then 4 rapid clicks.
Tell me if it works . Good luck
Pierre Kwok
March 2014