I'm unsure why you're unable to reply, but it's been 10 minutes since I posted those steps. If the screen is still not backlit then the power supply/LED driver board needs to be replaced, which is on average a $225 repair on this set. In this case, if you'd like, you can use the link below to locate a shop in your area:
Alternatively, if this is something that you're looking to try to repair yourself, then i would need you to double check that model number off of the back of the set, postback here with it, and then I can search for the board for your TV.
Other than that, I'm sorry for the bad news here and wish there were a quick fix.
If you need further assistance let me know. Before you go, PLEASE DO click at least a 3 STAR RATING, at the top of your screen (scroll up the page to get to the STARS). That is how I am credited for my efforts by the site. You can follow up any time as needed at no additional cost.