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Hannspree HF289H With Unstable Picture

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    #1

    Hannspree HF289H With Unstable Picture

    Hey all,

    I have a Hannspree HF289H monitor that started acting strangely a few days ago.

    Regardless of the screen resolution, refresh rate or input used (hdmi, VGA), every 1-3 minutes the image will roll vertically for a few seconds. It reminds me of an old VHS tape.

    I have also seen the upper corner of the screen turn white and spread outward, then just as suddenly the color will revert to normal.

    The logic board and power supply looked fine, no bulged capacitors. What could be causing these issues?

    Any help is appreciated, Thanks.
    Tags: None
    #2
    Re: Hannspree HF289H With Unstable Picture

    Post clear focused top down pictures of all your boards following my sig file below exactly. We want the picture compositions like so

    https://www.badcaps.net/forum/showpo...94&postcount=1
    --- 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.

    Please do not post inline and offsite as they slow down the loading of pages.

    --- end sig file ---

    Comment

      #3
      Re: Hannspree HF289H With Unstable Picture

      Here are the pictures, thanks.
      Attached Files

      Comment

        #4
        Re: Hannspree HF289H With Unstable Picture

        On your third photo of the logic board, with the power supply connected to the logic board, try measuring the DC voltage output of the voltage regulators. They appear to be U103, U101, U102 and U901? (to the right of U102). Use a mounting screw as your ground and measure the legs and tab of each regulator. Report your readings along with the part number of each regulator.

        Comment

          #5
          Re: Hannspree HF289H With Unstable Picture

          Originally posted by jetadm123 View Post
          OReport your readings along with the part number of each regulator.
          Like jetadm123 says, report them like so along with the part number (include all lines on the IC) of the IC. For example,

          U100
          AS1117-33
          pin 1 = 0.0
          pin 2 = 3.3
          pin 3 = 5.0
          --- 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.

          Please do not post inline and offsite as they slow down the loading of pages.

          --- end sig file ---

          Comment

            #6
            Re: Hannspree HF289H With Unstable Picture

            Here are the voltage readings, part number in italics.

            U101
            80e
            17-18L
            pin 1 = 0
            pin 2 = 1.8
            pin 3 = 3.2

            U102
            1084
            0809nL
            pin 1 = 2.4
            pin 2 = 3.6
            pin 3 = 5.1

            U103
            1084-33
            0813LL
            pin 1 = 0
            pin 2 = 3.2
            pin 3 = 4.8

            U904
            8cL
            1117L
            pin 1 = 0
            pin 2 = 0
            pin 3 = 0

            Comment

              #7
              Re: Hannspree HF289H With Unstable Picture

              You might want to measure U904 again as you seem to have no input voltage to the regulator.
              Last edited by jetadm123; 08-18-2012, 09:32 AM.

              Comment

                #8
                Re: Hannspree HF289H With Unstable Picture

                Originally posted by jetadm123 View Post
                You might want to measure U904 again as you seem to have no input voltage to the regulator.
                Also, unless you have an analog multimeter, report all the numbers on the multimeter.

                A regulator that measures 3.2 implies 3.20 which means it is bad (out of specification). However, if the real reading is 3.29, then report it as 3.29.
                --- 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.

                Please do not post inline and offsite as they slow down the loading of pages.

                --- end sig file ---

                Comment

                  #9
                  Re: Hannspree HF289H With Unstable Picture

                  This sounds a lot like a loose LVDS cable, especially the fade to white. Try reseating the cable going from the main board to the board at the top of the LCD.
                  Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                  For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                  Comment

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