There are ways you can test your TVs backlights, and if needed have them replaced. I coulde’t find a specific tutorial for this specific TV, but I did find several different ways you can test and troubleshoot the issue TV backlights.
[link|https://www.youtube.com/watch?v=1n-Nq8HLK20|How to test your TVs backlights]
[link|https://www.youtube.com/watch?v=58L_QcsQ9RU|How to replace the backlights]