I've had the problem and I solved it! (Asus TP500L)
Just push ton "on" button for like 30-40sec. As long as you can. If it doesn't work, try pushing the volume or windows button at the same time.
If it still don't work, just press alternatively. For a long time.
So mine boot up after pressing the "on" + windows button for like 30 sec.
However, now I can't really use easily the on button. It takes 30sec everytime. :/ Do someone actually have experienced the same problem after succeeding at booting up back the pc?