My Macbook Pro won't boot past white screen

I have a Macbook Pro and it won't boot past white screen for a while. I turned it off pressing and holding power button for some seconds and now it won't even show white screen. it's just stuck on black screen. after few hours of digging, i tried to turn on holding eject key and now i can hear chime and it came up with white screen and stuck there again. again i turned it off pressing and holding power button for some seconds and now as i try to turn it back on, nothing helped. even eject key wouldn't work. i'm stuck with black screen now and no chimes either.

PLEASE HELP!!!