I have a G4 powerbook, and the screen seems to be dead. That includes not only the display itself, but also the apple logo on the exterior and the little blinking light on the hinge. The laptop audibly boots, so it's not as though the laptop itself is dead; I had thought maybe there was a bad connector so I opened the patient up and everything looked good as far as a cursory visual inspection went. Any ideas on how to diagnose and remedy this? What to look for, even? I'm reluctant to take it in for service when that's likely to cost as much as I paid for the unit in the first place.