LG49UF6490's Logo shows but no picture and no sound
I have a 49inch LG TV (LG49UF6450).
"Hi @antronna ,
It may be a firmware problem since you say that the logo is coming up OK.
Try updating the firmware for the TV and check if this resolves the problem.
Here’s a link to the firmware support page.
Type 49UF6400 into the search box and then select the “49UF6400.AUS” option that appears below.
When you are on the 49UF6400.AUS software update page, select the Reference link on the right side, middle of the page and then verify that your exact model number is listed.
If your exact model is not listed in the reference list DO NOT do this as you will brick the TV!
If it is listed, download the TV software update guide .pdf file as well as the Software File (version 03.15.86).zip file to your computer. Use the guide to find out how to update the TV using a USB flashdrive.
It will not install if the software in the TV is the same version as what the downloaded file is, but given that the file is dated 06/14/2019 hopefully the TV won’t be updated to this version already.
I went back over the link I posted and realized that your model - 49UF6450 is not listed in the compatible models list only the 55UF6450 and 65UF6450 versions. It does mention a 49UF6430-UB - is this your model by any chance?
I couldn’t find your your particular model in the LG support pages. Try searching from where you are and see if you can find it. Search for LG49UF6450 support (or perhaps LG49UF6400 support- that’s how I found what I thought was it).
Unless you can find the correct firmware for your EXACT model or can confirm with LG that this may be the correct one, don’t try it
Sorry for misleading you.
You may have to contact LG to confirm or refute re the firmware.
You’ll notice on this link that it says “49UF6490.AUS software update” but then goes on to say SW File(Version 03.15.86) for **UF6400-UA, **UF6430-UB, **UF6450-UB and doesn’t mention the UF6490 models at all not even in the Reference list.
Still can’t find it anywhere else"
@antronna since you said that your “Logo shows but no picture and no sound” it will not be your backlight. The Logo gets illuminated by the backlight so if it shows your backlight is okay. I am not a friend of just going to go ahead and reheat just any IC. Sure, a reflow might work but in the case of your TV you’d have a couple of IC’s that could be at fault. At this point I would suggest you get a replacement main board. That is where the Firmware sits, the USB circuitry etc. is on this board as well. Try to get either a known-well used one or get one from a place that has good return policies just in case a new main board will not work. Going by your pictures your main board is a EAX66703203
@antronna Does your TV show the logo for ~1 sec before the screen goes blank then shows nothing? I’ve repaired that issue on an a similar model because the LED back lights were going bad. The back light would pull too many amps and auto-shut off the unit, even though they all still technically worked. When I took the TV apart, I found a small brown ring around all the LED’s.