What is acceptable Vloss for a capacitor?

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  • withalligators
    Badcaps Veteran
    • Jun 2013
    • 267
    • USA

    #1

    What is acceptable Vloss for a capacitor?

    Recapped most of the Capxons on a PS board, but monitor is still not working. Didn't replace two Rubycon 35v1000uf caps. Pulled them to test, I have one of those little component testers with the LCD screen. Multiple testing cycles put them at Vloss 0.5 - 0.8, capacitance at ~930, and ESR at 0.00 - 0.01 ohms. I also didn't replace the large main cap. It's 150uf450V, and tests at Vloss = 1.0%, C = 138.3uf, ESR= 0.46ohms. Should I replace these or is that acceptable and I should look elsewhere for the fault? The issue is intermittent, but not working far more than it is working.

    One of the caps on the PS that was visibly bulging had a Vloss of 21%, so that one is obviously bad. These Rubycons that I didn't replace are right next to it on the board.

    See this thread for a more detailed description, if you're curious.
    Last edited by withalligators; 04-04-2022, 03:45 PM.
  • eccerr0r
    Solder Sloth
    • Nov 2012
    • 8701
    • USA

    #2
    Re: What is acceptable Vloss for a capacitor?

    vloss (which still is vague in my books) depends on application, there are some applications where even 0.1% vloss is really bad.

    For bulk filtering I'd say anything under about 3% is acceptable, higher than that is dubious, but other people have differing opinions on this...

    Comment

    • withalligators
      Badcaps Veteran
      • Jun 2013
      • 267
      • USA

      #3
      Re: What is acceptable Vloss for a capacitor?

      Thanks. Where would a power supply fall into the tolerance scale do you think? I sorta doubt this is my problem, but something is causing my main (or Tcon) to not generate an image.

      Comment

      • eccerr0r
        Solder Sloth
        • Nov 2012
        • 8701
        • USA

        #4
        Re: What is acceptable Vloss for a capacitor?

        bulk filtering occurs in power supplies...

        Comment

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