Thank you! The backlight is fine, it is just the image that gets messed up. When I adjust the lid it, the image remains stable until there is any vibration (even a slight vibration). I doubt I have the skill to open the machine, but this is helpful because at least it may be worth the expense to repair. I don't think the cable is just loose because a tech at an Apple store tried reseating the cable a year ago, but it didn't work. Thank you again.