AVSFORUM (see google) seems to carry on discussions about such things.
I have a Sammie UNB6000 LED.
It stopped working, making clicking sounds, and won't turn on. I figured it wouldn't hurt to DIY (while I'm no pro, I've fixed many of my own electronics before and not clueless).
The capacitors on the old power board actually look fine, but I got a whole new power board anyway and installed it... and nothing. Same exact problem: Constant clicking sound, won't turn on.
I'm considering replacing the main board as well, but based on what I've read, it really does not seem like it would be the problem either? Any other suggestions? I would really like to salvage this TV.