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Samsung UN58TU7000FXZA Washed Out and Lines

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    #1

    Samsung UN58TU7000FXZA Washed Out and Lines

    Hello, i have posted in some other thread but i was hijacking someone else's thread it seems. I had the same model.. Anyway, here's the issue

    un58tu7000fxza samsung, originally boot looping.

    Taping a bit of the right side of the U ribbon connecting both sides of the TV's buffer board got the tv to boot, but no image. That is normal on this set.

    So i cut the VGH line on the board going to the ribbon, and fed VGH to the right side of the pcb directly, the tv powered on with no flashing, but it has lines on it.

    There's many things i don't understand, and it's not for the sake of the tv, it's really a matter of understanding whats happening.

    So, right now, i removed the VGH line to where i injected it on the screen's pcb, and the tv works fine, without taping. Did injecting VGH there cleared any shorts on it ? It seems like it? I don't understand.

    Also, im not able to figure out, which side of the screen has a defect.

    Watching some videos, it seems there was a way to 'isolate' the fault by cutting the CK1 to CK8 and VSS/STV/VGH/CLR/LC1/LC2 on one side of the pcb. I've then reconnected all these traces back since it didn't change anything, still had the same issue with lines on the left side alone.

    I watched some videos where south american techs fixed this one, by injecting some low voltage on one side into the VGH line to restore the color on the washed out side, there im not following what he's doing with the translated subtitles, a bit hard to follow.

    No shorts anywhere on the caps on the pcb of the panel either.

    Can anyone help on this one ? I'd really like to understand whats happening and fix it.

    For reference, here are the vids ive watched;

    https://www.youtube.com/watch?v=cwxSK4JGMg4
    https://www.youtube.com/watch?v=5PPPeFjplIU

    I've also managed to restore half an image with the U bridge flex removed, by jumping 2 points on the mainboard as instructed by these techs. It seems to enable video even if the U bridge flex is removed.

    I'm really being determined to fix this one, id really like to understand it. thanks for any help
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    #2
    Re: Samsung UN58TU7000FXZA Washed Out and Lines

    Anyone has some hints ? Thanks!

    Comment

      #3
      Re: Samsung UN58TU7000FXZA Washed Out and Lines

      all samsung TU series have been dying after 1 year (standard warranty period) with panel failures, the symptoms are either black screen with backlight and only sound, or tv rebooting, panel defect, if cutting clock or VGH pins did help but reapplying VGH leads to lines, it's an internal panel problem.

      Comment

        #4
        Re: Samsung UN58TU7000FXZA Washed Out and Lines

        Ok, so basically, there's nothing better that will be done on this one than what i did.

        However, these guys in south america were able to restore the full color on the bad side, it's clearly shown in these vids.. But i haven't been able to follow due do the language barrier, even with the subtitles, i don't get it.

        Lines are ok, but the washed out color ? Would be great to restore it.

        Comment

          #5
          Re: Samsung UN58TU7000FXZA Washed Out and Lines

          https://www.youtube.com/watch?v=5PPPeFjplIU

          it's a bit hard to follow spanish when spoken that fast, but that tv was rebooting, he says to check the main board dc-dc voltage (in 14V, out 12.8V), then to check both panel sides to see which one is causing the tv to reboot, test for shorts, he found none.

          Next is to remove these resistors and see if the rebooting stops. He cut VHG, then applied 12~13V and test where it stabilizes. After that, link those clock lines back and see which combination makes the colour on the defective side come back. He said that in this TV the only defective lines were VSS and CK6, if he tried to solder those back the tv would reboot.
          Last step in the video is that 12V was applied to VGH line, but then was removed? I did not understand what happened but I think it was back using the normal VGH. But the colour was not fully restored in the bad side, he says that it isn't perfect but good enough, and to explain it to the client.
          Last edited by Biruslapio; 11-08-2022, 01:24 PM.

          Comment

            #6
            Re: Samsung UN58TU7000FXZA Washed Out and Lines

            Ok, this what i understood it also. I cut all the lines one one side, but the lines did not dissapear, and the washed out was still present, with all the lines cut one one side and the U ribbon disconnected at the bottom, so i totally isolated the right side of the screen alone.

            When done, this side of the screen was lighted up, with black lines still.

            After that i reconnected all of the cut traces, when put the bridge back. So basically did all of that tiny soldering for nothing.

            Now, since i saw lines on that side that was isolated, does it mean that these lines are really coming from this side ?

            If it means that, well im gonna try the same exercise on that side, cutting all lines and re-connecting them back 1 by 1.

            I still dont understand why there are 2 issues at the same time, the washed out colors AND the lines..

            Are these 2 different panel issues, at the same time ? Or the lines are caused by 1 of the CK(x) lines, and that creates the washed out panel ?

            Comment

              #7
              Re: Samsung UN58TU7000FXZA Washed Out and Lines

              whenever a TV has those horizontal lines it will start from the defective side as really strong and get thinner and dimmer as it passes to the funcional other half. In your case they originate from the right side.

              Comment

                #8
                Re: Samsung UN58TU7000FXZA Washed Out and Lines

                Thanks !!

                Ok, but why is the other (left) side washed out, if the issue comes from the right ?

                I will proceed to disconnect (cut) the CK(x) lines on the right side to see if the image improves and then reconnect them 1 by 1

                Comment

                  #9
                  Re: Samsung UN58TU7000FXZA Washed Out and Lines

                  Hey, weird thing happened here. I got this email from badcaps, but the post isn't here, and this user doesn't exist on the forum ? I don't get it.

                  Dear cheebster,

                  elkcurry has just replied to a thread you have subscribed to entitled - Samsung UN58TU7000FXZA Washed Out and Lines - in the Troubleshooting TVs and Video Sources forum of Badcaps Forums.

                  This thread is located at:
                  https://www.badcaps.net/forum/showth...8&goto=newpost

                  Here is the message that has just been posted:
                  ***************

                  ---Quote (Originally by cheebster)---

                  Ok, but why is the other (left) side washed out, if the issue comes from the right ?
                  ---End Quote---
                  I am curious about the answer to this question. Do you have an answer for it yet?

                  happy wheels game (https://happywheelsgame.io)

                  ***************

                  Comment

                    #10
                    Re: Samsung UN58TU7000FXZA Washed Out and Lines

                    nice message heh, it was a scam link that got deleted

                    Comment

                      #11
                      Re: Samsung UN58TU7000FXZA Washed Out and Lines

                      Ah! Gotcha.

                      Comment

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