I just went and bought a new screen for my PowerBook G4 today!
Now all I have to do is wait 3-4 days. Finally, I'll be able to use it as a laptop, except I don't have a battery…
You have a 9500, does the G3 card work in it? If it works well there then it's likely a problem with your RAM, motherboard or possibly power supply. If it doesn't work all the time…