My VIZIO C50-m1 is not showing any picture but I can hear sound

@cookiemonster20 while the screen is dark but the audio playing shine a flashlight beam at an angle against the screen. See if you can make out shapes etc. In that case it would be the backlight array. If not, you will have to remove the back cover on your TV next and check the power board as well as the other boards. Look for anything obvious like burned components, loose cables etc. Remove the ribbon cables and reinsert. Check the cable connectors. Vizio has issues with cold solder joints on the connectors. Post some good pictures of your board etc. with your QUESTION that way we can see what you see.

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I’m working on a friends LG tv and it’s the same symptoms. I believe the backlight has gone out. It’s usually made up of light emmiting diodes. One or more have fried. As the LEDS are usually is series to drop a pretty high voltage, one going out stops the others from lighting. A good test (see on you tube) is shining a flashlight on the screen while the TV is on to see if you can detect a picture. Its called ‘the flashlight test’ - go figure. Pushing the menu button puts up a stable image. Do it in a darkened room. If you see a sort of ghost image, its the backlight. Troubleshooting it further will be difficult as you don’t really know why the light is out and tearing it apart requires some expertise. It could be a printed circuit board? To get to the LED’s you have to remove the fragile and delicate screen. Crack it and its new TV time. If you are not a techie, take it in for service, but mention you know its the backlight to keep from being bamboozled.