imac 27" left side display darker

One month after the 1 year warranty the displays left side of my IMAC 27" (middle 2011) will suddenly darker than the right. It's a problem with a rear panel little cable which supply energy at the LED backlighting. The problem is: why do Apple any action to fix the little problem? When I go to Apple Service Provider with my ill IMAC it will replace the whole display for a cost of more than € 600! But the display is't wrong! What can we do with Apple?