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Viewsonic va902 LCD recap

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    #1

    Viewsonic va902 LCD recap

    Recapped power board for Viewsonic VA902(aka HannStar JG171A) vs10715

    Symptoms: The display didn't power on. When connected the green power light turns on for second and then dims as the safety circuit kicks in. Then after some time when power is disconnected it is possible to repeat. Disassembled, in some places board was brown from heat, the build quality is low.
    I was able to turn it on if the LCD panel was disconnected, then powering on and allowing it to warm up and then connect LCD. It works until display is turned on. Another way was to heat a little with gun 2 mofsets in power board and then it turned on without problems, as starting power peak was minimized. Backlight worked ok. So the caps could be the cause, although seemed ok by look.

    Board: Date: 2005.05.18 2202130701P Ver:2.01 w/o audio



    Fix: Replace C823,C825 and just in case - C906,C922 . It didn't make a big difference on my pacient. So I replaced the C824 (10V 1000uF) too, and it fixed the problem. C824 is not a typical problem for these as didn't find it mentioned on net.






    I replaced C824 with 16V 1500uF as other caps were 16V and this seems the weak spot when board is old.

    Thanks to : http://monitor.espec.ws/section33/topic90393.html
    Attached Files
    Tags: None
    #2
    Re: Viewsonic va902 LCD recap

    C823,C825,C906,C922 = 16V 470uF
    C824 = 10v 1000uF

    Comment

      #3
      Re: Viewsonic va902 LCD recap

      Fixed another one. Changed all Elite caps with good ones.

      Some steps for easy disassembling:
      1. Unfold the monitor horizontally. Press the caps(chromed cylinders) from sides and pull out.

      2. Unscrew the hidden screws.

      3. Undo the screws at back.

      4. Unclip the protecting cover. Better heat it with heat gun before for easy removal as it is too crisp.

      5. Neverless some of clips can break as it seems it's mean to be closed once and for all. This can be fixed by gluing around the edge of failed clips.


      see the white crack


      6. The hardest part top open is the stand. There are clips on sides.


      7. Do the magic...
      8. After that - assembly is the reverse of disassembly
      Attached Files

      Comment

        #4
        Re: Viewsonic va902 LCD recap

        I have almost like same problem as you had. My VA902 just "flashes" the screen when i turn it on. So if i put my screen of, i see something about 1s but then its black again. Do you know whats the problem :O

        Comment

          #5
          Re: Viewsonic va902 LCD recap

          Originally posted by kappo View Post
          My VA902 just "flashes" the screen when i turn it on. So if i put my screen of, i see something about 1s but then its black again.
          This could be "2 seconds to black". See posts #13 and 14 for more details at

          https://www.badcaps.net/forum/showthread.php?t=10419
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