Viewsonic VG-930M Repaired..

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  • Solder Boy
    Senior Member
    • Nov 2006
    • 178

    #1

    Viewsonic VG-930M Repaired..

    but I still have a minor issue with it. It had a single bloated cap on the board. Original symptom was that it wouldn't turn it on, blue light was on for half a second then out it went.

    Thought my camera had taken the back side of the power/inverter board but I guess not.. oops!

    Anyway I replaced the bulged cap, checked the other ones.. the rest seem okay except for the big filter cap. It's reading about 1.5 on the ESR meter. I'm used to seeing them big ones read 0.

    Replaced that cap, turned the LCD on and it stayed on.. except I get a bit of a ripple on either side of the screen..sort of like a cycle. I wouldn't call it a flicker per se. Unit was made in 2006.

    Would that big cap cause the ripple I see on the screen? TIA
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    www.bcrelectronics.ca
  • Rtech
    Badcaps Legend
    • Jul 2010
    • 1095

    #2
    Re: Viewsonic VG-930M Repaired..

    I find the norm for the big cap is 0.1 to 0.4,on the ESR meter for Caps,rated between 100-120uF at 400v,so I think you need to change it long term anyway,as it will not get any better, and MAY solve the ripple as well.

    Comment

    • retiredcaps
      Badcaps Legend
      • Apr 2010
      • 9271

      #3
      Re: Viewsonic VG-930M Repaired..

      Originally posted by Solder Boy
      It's reading about 1.5 on the ESR meter.
      Just curious. Does your ESR meter check capacitance in addition to ESR?
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      Comment

      • Solder Boy
        Senior Member
        • Nov 2006
        • 178

        #4
        Re: Viewsonic VG-930M Repaired..

        Originally posted by retiredcaps
        Just curious. Does your ESR meter check capacitance in addition to ESR?
        Hi no it doesn't unfortunately.. haven't been able to find a decent capacitance meter that I can afford, the ones I have seen around here don't quite cut it for what I do.

        I can't find one that will go up to 3300uf.. the only one I found was one that went to 20uf if that.

        If someone can point me in the right direction it would be a help, because I realize sometimes the ESR might be good but the capacitance is not good.

        www.bcrelectronics.ca

        Comment

        • retiredcaps
          Badcaps Legend
          • Apr 2010
          • 9271

          #5
          Re: Viewsonic VG-930M Repaired..

          Originally posted by Solder Boy
          If someone can point me in the right direction it would be a help, because I realize sometimes the ESR might be good but the capacitance is not good.
          Well seeing how there are only 6 caps on board and you already changed the bloated one and the big one, I would change the other 4 to see if the ripple goes away.

          I don't know if this will solve your problem or not, but changing 4 caps would cost less than $2 in parts.

          If you live in the USA, there are some brand name capacitance meters made by Meterman for $25 (on ebay).

          http://cgi.ebay.com/Meterman-CR50-Ca...item2eafa2c2f1

          This one goes up to 20mF (milli farad).
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          Comment

          • Solder Boy
            Senior Member
            • Nov 2006
            • 178

            #6
            Re: Viewsonic VG-930M Repaired..

            Originally posted by retiredcaps
            Well seeing how there are only 6 caps on board and you already changed the bloated one and the big one, I would change the other 4 to see if the ripple goes away.

            If you live in the USA, there are some brand name capacitance meters made by Meterman for $25 (on ebay).
            Thanks for the info.. I haven't replaced the big cap yet.. I guess I wasn't clear enough about that. I will take your advice about the other caps.

            As far as that meter goes I'm in Ontario Canada.. I will see if I can find a dealer up here. Not too keen on having UPS or whatever and ship it here ( they charge $50 for duty brokerage) and as a Canadian we're only allowed to import $20 before we get slapped with duty and taxes.

            www.bcrelectronics.ca

            Comment

            • lucky13
              Badcaps Veteran
              • Aug 2007
              • 412

              #7
              Re: Viewsonic VG-930M Repaired..

              I would not fuss about the big 450V cap ATM.

              Change out the other 3 electrolytic caps with low ESRs cap too. If the ripple does not go away, it is likely your main board (logic board).

              There are a couple of regulator ICs on the main board. Check with DVM to see they are 3.3v and 1.8v outputs and not jumpy.

              Comment

              • smason
                Badcaps Legend
                • Feb 2010
                • 1652
                • Canada

                #8
                Re: Viewsonic VG-930M Repaired..

                Originally posted by Solder Boy
                Thanks for the info.. I haven't replaced the big cap yet.. I guess I wasn't clear enough about that. I will take your advice about the other caps.

                As far as that meter goes I'm in Ontario Canada.. I will see if I can find a dealer up here. Not too keen on having UPS or whatever and ship it here ( they charge $50 for duty brokerage) and as a Canadian we're only allowed to import $20 before we get slapped with duty and taxes.

                Depends on which UPS service. Normally I say "do not ship UPS" to anyone I'm ordering from.
                However, Digikey.ca uses (a bit expensive for small orders) a UPS service which is overnight, and $8.00 flat rate. NO brokerage fee, or duty, even though they ship from MN.
                My last order got placed on Monday at 2:00 PM, caps were on my desk Tuesday at 10:00 AM
                36 Monitors, 3 TVs, 4 Laptops, 1 motherboard, 1 Printer, 1 iMac, 2 hard drive docks and one IP Phone repaired so far....

                Comment

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