older 12" power book emitting loud noise

It doesn't turn on. All it does is make a loud droning noise that doesn't go away until I take the battery out. When I plug the power in the light indicates it's charging and the sound changes slightly. Any ideas? How screwed am I? will my hardrive be ok? Thanks

edit: I should clarify when I say it doesn't turn on I mean it doesn't boot up. The screen stays black. The Caps Lock light works though!

Did you try booting from CD? booting while holding Shift? Or will it let you get that far. Also try things listed here where they apply. Let us know how they work

deus_ex_machina said:

Did you try booting from CD? booting while holding Shift? Or will it let you get that far. Also try things listed here where they apply. Let us know how they work

Click to expand...

ok so this morning I press the power button just to see and it boots up like nothing happened. So after immediately back up everything on my hard drive and did some of the things in the list that you linked me. Haven't had a problem all day.