Well, you replaced the right parts! A white screen indicates a LVDS cable or LCD...

At this point, I see a couple of options:

1. the replacement parts are also bad.
   • Did you have this problem with the broken LCD? Do you still have it? What happens if you plug it back in?
2. the video processor (permanently affixed to the logic board) is bad.
   • Do you have an external display available? If so, connect your machine to it. If it displays the same symptoms, the logic board probably needs to be replaced.

Good luck! Keep us posted!