When i open my macbook, it gets stuck during white screen.. ( and it starts to make a noise which i recorded and uploaded here:
http://m.soundcloud.com/benevolentelmo/macbook-noise
can you boot with a DVD holding C key or R for recovery partition (10.7+) and enter disk utilities? There you can repair the drive or at least check it. If you get a invalid node structure error then you might have some hardware problem on the drive.
Btw, your questions might be best answered in the correct subforum, as this one is only for older powerpc macs
( and it starts to make a noise which i recorded and uploaded here: