TCL 65" U65E5800FS - Black shading after startup

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Stuckster
    Member
    • Oct 2019
    • 40
    • Australia

    #1

    TCL 65" U65E5800FS - Black shading after startup

    Hi all,

    TCL Model U65E5800FS (AUS)
    D65A620U (CN equivalent)

    My 65" TCL just started doing something strange. I searched the forums but couldn't find any threads covering the exact issue (possibly not using the right keywords).

    When I turn it on the title screen displays normally... a brilliant, consistent white with no artifacts and the TCL logo in the middle.


    Within 2 sec to 2 min the left and right side of the screen go dark, creating a vignette with only the centre illuminated.



    Same issue using my PC as the source.


    I have tested the issue with two separate sources using two different HDMI cables in all 4 HDMI ports. Same result each time. So it points to a hardware issue with the TV.

    I assume it's not a problem with the backlights since the title screen it fine.
    I also assume the T-Con is ok since the picture is still normal (albeit dark).

    I suspect this problem is similar to the seemingly common issue others have experienced with just one half of the screen going dark. But thought is was worth running it by everyone in case it was something new or different.

    Would it be something like a failure in the voltage supply to the backlights? Something that works correctly for a little while then gives out? Bad capacitor for example?

    Any suggestions or help with troubleshooting would be much appreciated.

    Many thanks
    Attached Files
    Last edited by Stuckster; 09-26-2021, 05:53 AM. Reason: Typo
  • neilc6
    Badcaps Legend
    • Nov 2015
    • 1550
    • Canada

    #2
    Re: TCL 65" U65E5800FS - Black shading after startup

    Bad backlights. Could be failing at lower or higher current. What happens when you adjust the backlight level?

    Comment

    • Stuckster
      Member
      • Oct 2019
      • 40
      • Australia

      #3
      Re: TCL 65" U65E5800FS - Black shading after startup

      How do you adjust the backlight level? I couldn't find an option in the user menu. Is that a manufacturers setting. How to access?

      Comment

      • R_J
        Badcaps Legend
        • Jun 2012
        • 9514
        • Canada

        #4
        Re: TCL 65" U65E5800FS - Black shading after startup

        Originally posted by Stuckster
        How do you adjust the backlight level? I couldn't find an option in the user menu. Is that a manufacturers setting. How to access?
        If you don't have a "Backlight" adjustment in the menu, try adjusting the "Brightness" if it has this adjustment.

        Comment

        • Stuckster
          Member
          • Oct 2019
          • 40
          • Australia

          #5
          Re: TCL 65" U65E5800FS - Black shading after startup

          Adjusting brightness affects the screen consistently. No relative change between the dark and light areas.

          Comment

          • angelos
            Badcaps Veteran
            • Dec 2012
            • 562
            • South Africa

            #6
            Re: TCL 65" U65E5800FS - Black shading after startup

            I think it is a panel related issue, perhaps the side COF IC's that are causing the issue. I had my Samsung TV doing this intermittently and i found one of those side COF IC's was touching on the metal frame. It seems as when they manufactured this TV they bent that COF IC like a "U". I straightened this COF IC and taped it down and the problem was solved. It's been a year now.
            My symptom was a darker horizontal bar that was appearing and disappearing with a thickness of about 3 inches.

            Comment

            • Stuckster
              Member
              • Oct 2019
              • 40
              • Australia

              #7
              Re: TCL 65" U65E5800FS - Black shading after startup

              Originally posted by angelos
              I think it is a panel related issue, perhaps the side COF IC's that are causing the issue. I had my Samsung TV doing this intermittently and i found one of those side COF IC's was touching on the metal frame.

              Hmm...thanks for that. I'll check it out.
              If in fact that is he problem it seems odd that it's just randomly started happening, with the TV sitting on the wall.

              Comment

              • diif
                Badcaps Legend
                • Feb 2014
                • 6978
                • England

                #8
                Re: TCL 65" U65E5800FS - Black shading after startup

                Originally posted by Stuckster
                Adjusting brightness affects the screen consistently. No relative change between the dark and light areas.
                I think they were wondering if the backlight is turned down does it take longer before going to black.
                Photo 1 shows a slight greying in the same position as the black, I suspect LEDs.

                Comment

                • Stuckster
                  Member
                  • Oct 2019
                  • 40
                  • Australia

                  #9
                  Re: TCL 65" U65E5800FS - Black shading after startup

                  Originally posted by diif
                  I think they were wondering if the backlight is turned down does it take longer before going to black.
                  Ahh, got it. BTW I found the Backlight setting
                  No noticeable change in the time taken for the backlights to dim when the backlight is adjusted up or down (tested several times).

                  Originally posted by diif
                  Photo 1 shows a slight greying in the same position as the black, I suspect LEDs.
                  There is a very slight vignette in the corners in "normal" mode which I suspect may be common in mid range LCDs. But the camera has definitely emphasised the effect.

                  Comment

                  • Stuckster
                    Member
                    • Oct 2019
                    • 40
                    • Australia

                    #10
                    Re: TCL 65" U65E5800FS - Black shading after startup

                    Interestingly, the problem has gone away this afternoon!

                    At the same time as testing the backlight setting (which had no affect), I also went to the Home screen, which we don't normally do since we run everything from a Mac via HDMI. I also connected the TV to Wifi (which we also don't usually have connected, since it's not needed).

                    I don't see how either of these actions could have actually solved the issue and suspect it is just coincidental, but you never know?!
                    It seems more likely that not using the TV for a couple of days has allowed some component to reset or return to normal working parameters. I guess I'll monitor over the next 48 hours and see if the issue returns.

                    Thoughts ??
                    Last edited by Stuckster; 09-29-2021, 01:59 AM.

                    Comment

                    • Stuckster
                      Member
                      • Oct 2019
                      • 40
                      • Australia

                      #11
                      Re: TCL 65" U65E5800FS - Black shading after startup

                      Ok. This is getting really weird.

                      We used the TV for a few hours this evening. At first, like I mentioned, the screen was back to normal, the problem had seemingly completely gone.

                      Then after a couple of hours I noticed that the darkened area had returned, but this time it was down the middle... the complete opposite of what happened in the first instance.


                      Attached Files

                      Comment

                      • angelos
                        Badcaps Veteran
                        • Dec 2012
                        • 562
                        • South Africa

                        #12
                        Re: TCL 65" U65E5800FS - Black shading after startup

                        I still say it's panel related.

                        Comment

                        • Stuckster
                          Member
                          • Oct 2019
                          • 40
                          • Australia

                          #13
                          Re: TCL 65" U65E5800FS - Black shading after startup

                          Originally posted by angelos
                          I still say it's panel related.
                          How would you begin to troubleshoot a temperamental issue like this?

                          Comment

                          • angelos
                            Badcaps Veteran
                            • Dec 2012
                            • 562
                            • South Africa

                            #14
                            Re: TCL 65" U65E5800FS - Black shading after startup

                            I would loosen the bezel and when the tv does the shadow thing i would lift the glass to see if my back lights are causing this issue. Just maybe its them, like a string of leds going dead. You seem the funny thing is that the LED driver circuit is quick to cut the power to the entire back light circuit if a fault is detected so i dont know if it is back light related in your case.
                            Look to see if it is your leds. If they are all lighting up then obviously it is panel related. It could be one of those COF bonded IC's. In that case you can toss the tv in the landfill cause you will need to replace one of those COF IC's Tracing where the fault is i would suggest you go to youtube and watch a number of videos talking of panel issues. Unfortunately most of them are in hindi, malaysian or some other foreign language. I can't help you with this issue unless there is someone on this forum group that has experience.

                            Comment

                            • Stuckster
                              Member
                              • Oct 2019
                              • 40
                              • Australia

                              #15
                              Re: TCL 65" U65E5800FS - Black shading after startup

                              Thanks. Yeah I'm pretty sure all back lights are ok since the TV is working fine some of the time.

                              Just to clarify, when you say it could be "panel related", do you mean one of the main boards (Power, Main, LCD Driver, T-con etc) or do you mean something specially isolated to the panel?

                              Comment

                              • Storyteller12
                                Badcaps Veteran
                                • Jun 2020
                                • 624
                                • USA

                                #16
                                Re: TCL 65" U65E5800FS - Black shading after startup

                                It’s either the panel or backlights. I’m betting backlights. You need to test them with a led tester or remove the panel and fire it up to see.

                                If it’s the panel it’s most likely trash. If it’s the leds you can replace and enjoy the tv again. Either way your are gonna have to take it apart.

                                Comment

                                • diif
                                  Badcaps Legend
                                  • Feb 2014
                                  • 6978
                                  • England

                                  #17
                                  Re: TCL 65" U65E5800FS - Black shading after startup

                                  Reads like a bad LED(s) somewhere. OK until it warms up then it fails.

                                  Comment

                                  • Stuckster
                                    Member
                                    • Oct 2019
                                    • 40
                                    • Australia

                                    #18
                                    Re: TCL 65" U65E5800FS - Black shading after startup

                                    Yeah I don't get it. TV has now been fine for 2 days.
                                    Are LEDs known to be very temperamental? They seem like the type of component that is either working or isn't working.

                                    Comment

                                    • angelos
                                      Badcaps Veteran
                                      • Dec 2012
                                      • 562
                                      • South Africa

                                      #19
                                      Re: TCL 65" U65E5800FS - Black shading after startup

                                      Originally posted by Stuckster
                                      Thanks. Yeah I'm pretty sure all back lights are ok since the TV is working fine some of the time.

                                      Just to clarify, when you say it could be "panel related", do you mean one of the main boards (Power, Main, LCD Driver, T-con etc) or do you mean something specially isolated to the panel?
                                      No, I am talking of the actual glass LCD panel. There are flexi ribbons connected to the glass. We have gate COF and Source COF IC's and these chips and their connection onto the glass are problematic.

                                      Comment

                                      • angelos
                                        Badcaps Veteran
                                        • Dec 2012
                                        • 562
                                        • South Africa

                                        #20
                                        Re: TCL 65" U65E5800FS - Black shading after startup

                                        Originally posted by Stuckster
                                        Yeah I don't get it. TV has now been fine for 2 days.
                                        Are LEDs known to be very temperamental? They seem like the type of component that is either working or isn't working.
                                        Actually they can be intermittent.

                                        Comment

                                        Related Topics

                                        Collapse

                                        Working...