I've also seen problems arise such as display and power issues because of this certain cable not being seated in all the way.   Check the cable that is circled yellow in this photo.  There are identical pluggins on each end of this cable.   You can use a small screw driver to push the  connector into the plug on the opposite end of the cable that is circled in yellow.  This one is harder to reach at which makes a screwdriver more helpful.  Take a look at the other cables as well. Make sure they are seated all the way.  This is worth a shot before sending it off.

You can use this tutorial here to help you disassemble the display.