Electronics/HD LCD TV has power, but no functions
The LCD screen of my Vizio VX42L flickered when I first rescued it some months ago, but now only the screen backlight is lit, a steady glow when powered on, and there are no displays shown when other buttons such as Menu, Channel, Volume, or Input are pressed. (As I recall, the same was true when the screen flickered.) The power button only toggles the set on and it must be unplugged to power down (I'm confident that wasn't true when the screen flickered). The Vizio logo lights amber when plugged in, white when on.
When I was standing the set up to take video of the screen, there was a loud 'crack' of plastic and while everything exposed looks the same and unbroken, hopefully it was just like the frame caught on something then freed and it was not this that changed things and I've now irreparably broken it.
I've read at other help sites that capacitors on the inverter board need replacing (when flickering), to that it's the main board or power supply/PSU.
Since the screen no longer flickered, I didn't take video, but just photos, as well as of the interior so maybe someone can point out just what to test & replace. They can be found here: http://imgur.com/a/HpgiQ
[cross-posted at Home Theater]
Yes, it could be those known capacitors that need to be replaced. But, it could also be a bad power supply board.
Maybe you have seen/read these comments;
The repair kit is around $20 and a new board is around $80.
It's hard to say what the real problem is without physically seeing it and doing some simple (if not comprehensive) testing.
Hope this helps you find the solution.