LG TV - powers on, but black screen after LG logo, backlight is on

@crashxxx backlight on without video is usually a main board problem you did not tell us if you get any sound. You need to check out all your video inputs and see if that changes anything. If it does not remove the back of the beast and take a look at all the boards for any obvious damage (leaking or domed looking caps etc.). Post pictures of your boards so we can see what you see. Use this guide Adding images to an existing question for that. The problem could be the panel but it could also be the power board or the main board.

"Had same problem with a LG 5510

Was watching TV and screen just faded to black sound remains

Logo comes on upper left for few second's then fades to black

Disconnected everything gave the back a good vacuum noted was dusty near some of the ventilation slots

Screen came back on after restart only been 10 mins but colour contrast vibrant looks good"

"It’s a problem with the motherboard.

solution may sound extreme but it works.

Remove board and place in Warm oven for 20 minutes. Allow to cool , reinstall and all should be good."

Hold down power button on bottom of tv for 10 seconds when it’s on.

"the Led back light is bad, leds connected by series, one dead all will not work, check this video: https://youtu.be/LaV6aQ8LIpw

Update (11/17/2021)

If the logo showed for couple seconds then off then it could be the leds back light is bad, maybe just one of 40-10 less."

"I've been stressing about this. My tv would go dark only if the picture was dark or tv seen was at night so I would crop the picture and have a steady on background on the section that would go dark.

The other strange thing is that in initial setup mode the TV would stay on with perfect picture forever, but when done it would go dark again blank u can see picture only by shining a torch onto the screen and also barley.

But for the past week my picture has returned I no longer have to crop the screen everything is as it should be.

The issue was power, we unplugged alot electronics changed the multiplug and immediately saw a difference, check power supply to the socket as well"