|If the cable itself is OK it could be the screen or (less usual) the graphics module. |
Sometimes tapping with something like a end of a pencil can reveal a poor connection somewhere (symptoms come and go with tapping in a particular area). Also see if it the symptoms change when moving the screen back and forth.
Applying freezer (from Radio Shack) to suspect areas such as the graphics module can also reveal things - watch the screen for changes.
Always pop back and let us know the outcome - thanks
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