My samsung lcd tv suddenly didn’t show any picture on screen but nothing happened to the audio.Someone please helpme how to repair it.
If you have no volume bar or menu showing on the screen, then it cannot be anything you have wired wrong.
to see the picture on an LCD TV, you need to have back lights. the light shines through the lcd panel and you can see the picture. I suspect that you have video on the screen, but you cannot see it because the back lights are not lit. To prove this simply turn the tv on in a very dark room and tune in a channel so you can hear the audio. then with a powerful flashlight, point it into the screen and look around the edge of the flashlight for evidence of video. Be careful not scratch the panel with the flashlight as you place it on it..
Back to your problem, the back lights are tiny florescent bulbs and a ballast to run them, similar to the ones in a shop light. If the lights go bad or the ballast fails them you will get your symptom. Many times if the lights fail then not all of them will fail all at once, so the others will start up and then after a second they will cause the ballast to quit trying. In this case when you first start up the tv repair, you will see a slight glow on the screen (if the room is really dark). Many times you can see which light isn’t working, there will be a darker horizontal stripe. This usually means the panel must be replaced, and unless it’s cover with a warranty, you will probably not fix it due to the costs.
If it never glows slightly, then replacing the ballast may fix it. On some set this board is not available separately, but many have now been released. And on newer sets the ballast is part of the power board, and they have issues with a diode shorting so the part is cheap. With out a model number, I’m spit balling.
The last thing that can happen, is there is a slight back glow and no picture is being displayed. This is almost alway the fault of the lcd control board. Like the ballasts, many of these boards are now available without buying the whole panel.
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