The majority CEs were cursed with a faulty video cable where when it goes, a 1/4 to 1/2 your screen would going out as a solid white horizontal bar from the top. They have been recalled for that by Apple and my 5300ce went to "The Apple Repair Shop" 4 times for that exact same repair. On the 5th time the recall was over and cost me $150 to get it fixed and it died one more time so I left it at that, leaving me to use the bottom 3/4 of the screen.

Mind, it could be anything, but the main symptom is that when you press the left side of the bezel where it goes white, it momentarily restores the video until you let go. But this is only good for a few tries and this trick eventually wears out. If you see a 5300ce on Ebay with "a video problem", this is the problem. This guy barely mentioned it at the bottom of his page: http://www.kevinomura.com/powerbooks/powerbook5300/

Due to the micro soldering on the LCD, I would not try to solder in the cable my self as I believe would fix this issue. Or stuffing the area with some thick fluff to make the connector press against the LCD might also work. But my LCD Bezel is full of micro cracks and epoxied scars holding it together, so I limit the number of times I can take it apart and put together.