Is the picture you have complete? Is there a black band along the top as well? If so, it may be because you are providing an HD aspect ratio of 16:9 instead of the TV native 4:3.
Try hooking up a VCR and watching a tape. Do you still have the black band on the bottom?
My Toshiba tv keeps blinking Toshiba entertainment system across the screen and it wont let me use...
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My Toshiba tv keeps blinking Toshiba entertainment system across the screen and it wont let me use the menu. Can it be saved?