Tv screen flashes once, has sound but no picture repair. LG 50LN5100

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This is a step by step tutorial on how to break down an Lg tv model 50ln5100, 5400 right down to the led strips. How to find the bad led strip, voltage measurements, and replacing individual bad led’s. The problem with this tv is that it turns on, the screen flashes 1 time then there is no backlight, no picture, but the tv still has sound.

50 Replies to “Tv screen flashes once, has sound but no picture repair. LG 50LN5100”

  1. GW H

    Ran into the same situation. What we did was follow the 8 or so recommendations before you have to open up the TV. What we also tried was, Go into settings and turn “off” the back light. It worked. Then since then I’ve turned it on incrementally. First at 10%, then after a few hrs to 15%. Still working, after 1 day. We don’t really want to spend anything on this unit if we have to. So far so good.

  2. Ham Fitness

    I have a similar issue with my LG, only difference is when I boot it up, the LG comes on then after 3 seconds it goes black. I can still see a picture on the background if I use a flashlight on it.
    not sure if faulty led strip or power inverter on the power supply board.

  3. AlexPGunn

    Great video. Used it to take apart a 55LN5310, found out the ribbon connector from the driver board to the panel was damaged. My symptoms was a gray cloud in the middle of the screen with a few vertical lines on the side of the TV with the damaged ribbon connector. Sound worked, back light worked. This isn't repairable but it's nice to know what's actually wrong with it, and I wouldn't have been able to do it without this video!

  4. James Sutton

    Hi Big Dog, working with lg's lb series tv. The big lens caps that fall off, but are a pain to get focused and you can see them once you put the tv together. Do you have a remedy for this problem.

  5. Piledriver

    Enjoyed your video, I learned something! Trying to decide to call out a tech or get a new 70” tv. My set has minimal problems 1/3 picture is kinda dark but picture is all there. Thanks for the video

  6. koukias electronics

    my friend never do this go boy new led bars the cost is not so high and you will be sure that it works while next week you maybee loose another led and when you bridge to much then you will have overheating and other problems so never bridge the leds

  7. Modog Aguilar

    I had same problem so I payed 500$ for every tool a parts needed to fix tvs back lights from shop Jimmy. Com

    All your TV needs get yours
    I fix 6 50"
    1 75"
    An 3 55"
    1 60"

    No I got a vizio the only brand from LG,sharp,Samsung,
    An sceptre an RCA
    That has back lights on but no videos or sound

  8. Darren King

    Hello, great helpful video

    I'm hoping you can help me out with my problem, I have a 60" RCA LED TV that the backlights work for a little bit then they go off, if i turn the TV off then back on the backlights will work for a little bit longer.

    Iv checked the DC voltage to the LED's when they are working and it fluctuates from 180V to around 170V then either climbs or drops, and when the lights go out the voltage is zero. I tryd changing the power/driver board, but it was doing exactly the same with the other board.
    I thought that my board was faulty as the voltage was zero when the lights didnt work, but now I'm thinking Im wrong. Now i'm thinking it might be a LED or 2.

    I have ordered a LED light tester so that will be my next step, but any help you can give me would be great.
    Thank you

  9. The D_O_Double_Gee

    Hey there bigdog, appreciate u man. Just stumbled on ure video but will be following. I play some guitar an mess around and repair electronics an computers. [ I like to keep a guitar pick in my tool kit ] for things with plastic clips like that TV bezel. For when I don't want to leave any kind of mark from a flat screwdriver.

  10. Orlando Johnson

    My nephew gave me the exact tv u demonstrated!!
    The HDMI is damaged on the Main board (inputs RCA Cable area!)…. but I suspect the LED are the main culprit!!!
    He played games all thru the night on this tv!!!
    My question is… are the LED lights AC or D.C. Voltage applied to them!
    I'm guessing 115 volt to the tv and a rectifier or something from the Mother board feeds the LEDs!?

    This video was very informative & encouraging ….
    Soon I will make an attempt to replair!!! 50" screen ? is worth a tinkering ??

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