PowerBook Screen Problem- Please Help!

[tviolation]

I just got a PowerBook 520c from a friend to use as a backup to my iBook. They were not the original owner of this machine, and it has some issues which I am trying to fix. The screen is the main problem. Sometimes it will not come on at all without fiddling with the orange connector ribbon beneath the screen, and when it does come on there is a rectangle in the upper right corner of the screen which does not display the screen image and is a bright orangish yellow color. I have a feeling that it is probably a problem with the video interconnect board or the connector ribbon, but I'd like some other opinions before I invest money in buying parts. I am tending to think it is not a problem with the screen itself, as the rectangle is perfectly smooth along the edges. Any thoughts?