There appear to be no TV repair forums. There used to be but as folk demanded free and "correct" diagnosis those that helped, fled.
The answers to fixing your own TV has never changed in spite of this. You need a service manual and the training. Or you guess. Here's some tutorials on repair: http://www.shopjimmy.com/tv-repair-tips
I replaced one led strip of my tv after tested defective. The backlight is now on and all led strips light are working normally but the tv is still not showing. What is the next thing to do.