Keyboard Backlight Problems

Hello there everybody, I have a mid 2009 macbook pro that I am planning on selling, but there is this gaping problem with the keyboard. The backlight only lights up a strip down the middle and along the top of the keyboard. Changing the brightness settings does not help, and this happens across all operating systems. Nothing has ever been spilled on it, and it has never been dropped; it has pretty much been sitting on a desk it's whole life. Is there a way I can fix this without opening up the computer? I'm comfortable with doing that, but I'm just wondering if anyone else has had this problem or if there is an easy fix.

Thanks!