mark,
does the screen flicker if you tap on the laptop?
if so, it might indeed be loose ribbon cable between the motherboard and the lcd screen (it's also possible that the cable is starting to break). in any case, you will need to open your laptop. once open, check whether the cable is properly plugged in. if it is, you might need a new cable (there's also possibility that it's loose on lcd end, I'm not familiar with PB laptops).
dupalopez, June 2007
