You can find YouTubes where the backlight comes up, the overcurrent is detected and the backlight goes out.
To work this you'll need the service manual as it has the steps to troubleshoot. As I don't own this manual you can get it over at samsungparts.com
The other day I flipped the breaker off to replace a light fixture and when I flipped it back on my TV (LG 42LN5300-UB on a surge protector) wouldn’t come back on. I tried another TV in it’s place and it works fine. I moved the TV in question to another location and it still didn’t work. You can see “no signal” flash on the screen briefly and then go off. Then it will briefly flash on in a different place on the screen and go off. This keeps repeating in different locations on the screen. That being said I’m assuming the backlights are not my problem. I tried a new power board but that didn’t work. I’m hoping someone can guide me in the right direction so I can fix this. Thanks!