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LG TV - Turns on with blacklight & menu visible but no actual pictur

Hello all,

This is concerning my LG television model 47LV4400-UA. It powers on (red standby light turns blue) and the menu appears on the screen, but there is no picture. “No signal” message on all inputs.

I tried all the HDMI ports and switching HDMI cables for the cable box. With the 2nd cable, the screen went solid pink but I think that was a faulty cable I had around. With the 3rd cable, a message “HDCP authorization failure. hdmi port is disabled” appeared over the picture, then “No Signal” returned after 10 seconds. I plugged in the original HDMI cable and reset the cable box. I again received the “HDMI port disabled” message as the cable box booted up, followed by the “No Signal” screen.

I also tried streaming video using my Chromecast and audio would play through the TV, but no picture. Reset the Chromecast, same problem. The next day, no audio or video.

Any thoughts on the possible issue? I unfortunately do not have another TV to test the devices on

Thanks for your time!

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Hi @ayepes ,

You said that there is “No signal” message on all inputs", then just relate to HDMI.

Have you actually tried the other input types at all e.g. composite or component?

It may be if the others work that there is a problem with just the HDMI controller section of the TV.

Apologies if I am wrong about this and you did try all input types

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Alexander Yepes no picture but shows the menu is commonly caused by a bad main board. There is a slight possibility that it could be corrupted EEPROM. Your service menu may have a reset for that.

If that does not help, remove the back of your TV and take a look at your boards. Post some good pictures of those with your question so we can see what you see. Use this guide 在已经存在的问题里加入图片 for that. On the Mainboard should be a component labelled U14 which is the system EEPROM . Let us know once you found it and post some good images of location on the board etc. Temporarily bridging pin 5 and pin 8 with something like a paperclip should reset this EEPROM. Do this only after you check everything else first.

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Thank you for your response. I added a few pictures to the original post. That's about as clear as I could manage with my phone, but I could re-attempt with an actual camera if you'd like clearer pics. The 4 was cut off, but I'm pretty sure that's the U14 component in the last two images. The TV menu is not very extensive, could not find any where to reset the EEPROM.

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@ayepes yup that is is. You can give it a try and briefly shorten pin 5 and 8. Picture is a bit unclear but it looks like there is a kerf on the bottom left of the IC that should be pin 1. That would make top left pin 8 and top right pin 5. Of course as a general disclaimer, you are doing this at your own risk ;-)if it does not work or shorten it out!

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