I am charging my Ibook and I turn it on. The green light appears and i hear it turn on but there is no screen it is still black. what do i do? do i leave alone for a while? help!
Ivan, thanks for your suggestion. I tried to hold down the keys, but never got a white screen.

Any other recommendations?

Try clearing the N-Vram. Do these steps.

Make sure the computer is off.
Turn on and hold the apple key, option key, and the O and F keys. (Wait until you see a white screen)
Then type reset n-vram then press enter. Then type reset-all and press enter.
The computer will restart that should do it.