Sadly, your display does indeed have a problem. One or more of the ribbon cables has failed these cables are part of the display assembly. So far I’ve not found the part on the open market so you’re only hope is to go to either an Apple Store or Apple authorized service center for them to do it. I strongly recommend you save your paperwork as I’m sure Apple will be offering a extended warranty program for this defect in the parts design.
If you have any bad or sticky keys, you might want to bring your system in for the free extended warranty program for it (Apple Store), see what happens when you don’t extend the display too far showing them the key defect, then when you pick up the system after the repair, extend the display see what they say and do ;-}