RE: Uneven backlight or screen uniformity issue on Latitude E7470
Thank you for the update.
Well, could you kindly check if the external monitor works fine?
Also, have you tried the other steps mentioned in my post?
Lastly, could this be your perception?
If the external monitor works fine, then the issue could be with the LCD. Write me a private conversation with the service tag and your contact details(Name and Email), so I could check the warranty options for you.
Let us know if you have any other queries.