Panasonic th43pv500b

[royar]

I hope i am doing this right. this is my first post. I have a panasonic th42pv500b and in the bottom right hand corner of the screen I have a black rectangle about 4in wide and 10in deep. The outer half has a white band at the top which changes to green about two inches down and then varies in color for about another inch. the set works fine apart from this. Has anyone any ideas.