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Hanns-G HG281D turning OFF on HDMI waving on VGA

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    Hanns-G HG281D turning OFF on HDMI waving on VGA

    Hello everyone. I have been reading this forum for a quite wile now, loads of good information.
    However i have a quick question regarding my old Hanns-G monitor.
    The monitor turns off if i plug it via HDMI (blue light is constantly ON).
    Now if i use analogue (VGA) there's two green (sometimes one) lines appear on the right side of the monitor as well as the picture itself is wavy.
    It needs good 30 mins before monitor back to normal (waves and green light disappear).
    Now after monitor warms up (after an hour or so) i can sometimes switch the cable to HDMI and monitor works just fine.
    I have tested voltages while monitor is on stand-by (i get steady 4.98V on one output) in addition i get +12 and +14 if the monitor is in its active state.

    What do you think can cause such a behavior?

    Thank you and sorry for my English
    Attached Files

    #2
    Re: Hanns-G HG281D turning OFF on HDMI waving on VGA

    The caps on the logic board (the same board you plug your video cables into) are a known problem for your model monitor. You can first try the usual things like removing the ribbon cables from the logic board, cleaning them, and reseating them. If that doesn't work, replace the caps.

    Comment


      #3
      Re: Hanns-G HG281D turning OFF on HDMI waving on VGA

      thanks for your reply, previously i have replaced 22uF 400V cap on power supply board (it measured low capacitance). No ripple on any of the output DC.
      Now i have replaced two 100uF 16V caps on logic board (got 60uF and 0.6uF readings for those). Please see the pictures attached.
      Changing those two caps fixed blinking issue as well as there is no flickers or any other artifacts on the screen except the vertical green line.
      Where should i look to fix that?
      Much appreciate your help.
      Attached Files

      Comment


        #4
        Re: Hanns-G HG281D turning OFF on HDMI waving on VGA

        Originally posted by accxer View Post
        Changing those two caps fixed blinking issue as well as there is no flickers or any other artifacts on the screen except the vertical green line.
        Carefully re-read jetadm123's post #2. If you haven't reseated and cleaned every internal connector on every board, then do so or say that you have done so.

        Also, jetadm123's advice was to replace ALL the caps on the logic board. Unless you have an ESR meter and tested every capacitor out of circuit to verify they are good, there is no way of knowing if the capacitor is good or not.
        --- begin sig file ---

        If you are new to this forum, we can help a lot more if you please post clear focused pictures (max resolution 2000x2000 and 2MB) of your boards using the manage attachments button so they are hosted here. Information and picture clarity compositions should look like this post.

        We respectfully ask that you make some time and effort to read some of the guides available for basic troubleshooting. After you have read through them, then ask clarification questions or report your findings.

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        Comment


          #5
          Re: Hanns-G HG281D turning OFF on HDMI waving on VGA

          The green line looks like a panel defect. It most likely has nothing to do with the logic board.

          If cleaning and reseating the LVDS cable going from the logic board to the panel does not fix it, then the problem is likely to be bad tab bonds from the Tcon to the panel, and cannot be repaired. You can try tho. Take off the metal shield of the Tcon and run your finger over the flex cable ribbons going to the panel. If you're lucky, the green line will go away when you touch a certain area. This can sometimes be fixed by figuring out something to keep the ribbon pressed in place.
          Originally posted by PeteS in CA
          Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
          A working TV? How boring!

          Comment


            #6
            Re: Hanns-G HG281D turning OFF on HDMI waving on VGA

            Since the green line goes away after 30 minutes, try using a hair dryer to accelerate the removal of the green line. First, heat up the logic board caps with the hair dryer. If the line goes away, then replace the remaining caps. If the line doesn't go away, heat the ribbon cable tab (where the cable end is bonded to the LCD pane) associated with that line. If the line goes away, then it's a panel defect and not repairable.

            Comment


              #7
              Re: Hanns-G HG281D turning OFF on HDMI waving on VGA

              Thank you guys for your inputs.
              I have used ESR meter to test the caps on a logic board.
              Also have cleaned the cables prior posting on this forum.
              Now for the green line, strangely i have carefully pressed the screen with my thumbs and moved it a bit (the screen actually moves around).
              After this the green line disappeared, this screen is a bit of a joke. Well at least now i can use it as a secondary screen so that my wee girl can watch movies.
              Will let you know if the green line comes back.

              Comment


                #8
                Re: Hanns-G HG281D turning OFF on HDMI waving on VGA

                Please see this thread:
                https://www.badcaps.net/forum/showth...632#post254632
                Never stop learning
                Basic LCD TV and Monitor troubleshooting guides.
                http://www.badcaps.net/forum/showthr...956#post305956

                Voltage Regulator (LDO) testing:
                http://www.badcaps.net/forum/showthr...999#post300999

                Inverter testing using old CFL:
                http://www.badcaps.net/forum/showthr...er+testing+cfl

                Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                http://s807.photobucket.com/user/budm/library/

                TV Factory reset codes listing:
                http://www.badcaps.net/forum/showthread.php?t=24809

                Comment

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