My friend has a MacBook and this morning when he tried to turn it on it wouldn't boot. The battey is fully charged...tried with and without power attached. When pressing the power button the sleep light comes on and you can hear a few things spin up...the screen flashes real quickly too...but then nothing happens... I have reset the PRAM (?) and PMU, but this didn't seem to solve it. Any other things we can try?? Thanks!