The phone will got backlight or other display problem after a long time of using. but i don't recommended you replace the backlight, because you need specialized tools and expert repair skill, i suggest you get a whole [https://www.witrigs.com/oem-lcd-with-digitizer-for-sony-xperia-z3-compact-white|lcd screen with digitizer for Sony xperia z3 compact.] (We also offer repair tools and repair guide )