LED Back Light failure

three days ago, my screen started to flicker and the bottom of the screen began to dim with gray triangles appearing across the screen. I took this to mean that I was having problems with the LED back light power supply. After 5 minutes, the screen went totally blank. I can barely make out the what is on the screen so the system is still working. Since I bought a service agreement, I called Apple and they immediately sent me a box. I received an email today saying that it would cost almost $1,300 because there is an indicated patch that said that the unit had water damage. That was a surprise to me and additional research has indicated that this marker can turn pink due to moisture in the air. I researched iFixit to see if there is anything part to replace that would fix the backlight but all I seem to find is replacing the display. Is this correct? Thanks for the support.