This morning I went and woke up my powerbook. Everything was fine for about 5 seconds and then the backlight started flickering and then shut off. The actualy screen is fine, like if I shine a light on it I can see the dark shapes of the pizels and what should be on the screen. If i use the screen brightess adjustment and turn off the backlight and then turn it on again, it flickers for about 3 seconds then shuts off. So it somehow still slightly works. But it's basically unusable. What the hell do i do? Will this cost me a lot of money ??