Home Forums Product Discussion & Questions BeoCord Beocord 8002: Did I get the capacitor orientation correct here?

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  • #47714
    quattttro
    BRONZE Member

      This is board #3, playback/bias, on a Beocord 8002. Looking at the schematic, it seems sometimes the positive and sometimes the negative end of the cap goes to signal ground, so I just want to make sure I got it correct here.

      #47715
      Mark-sf
      BRONZE Member

        I can’t tell from your picture but the correct orientation is marked on the board.

        #47716
        Glitch
        BRONZE Member

          Looking at the schematic, it seems sometimes the positive and sometimes the negative end of the cap goes to signal ground

          I assume that you are referring to things like C2 & C204? The schematic makes sense since the “negative” lead of the capacitor is connected to a voltage lower than ground. This would keep the electrolytic capacitor (properly) forward biased.

          I can’t tell if how the capacitors are installed on the circuit board are correct. Markings on the board are usually accurate, but not always. Mistakes happen in printing the boards and I don’t blame any manufacture for not scrapping boards for this kind of mistake. Same goes for printed schematics. Many times they “fix” the issue by an obscure errata statement.

          The best practice is to install new capacitors with the same orientation as the original ones. Taking “before” pictures of the circuit board can be really helpful as part of the quality control or debugging process.

          If all else fails, verify that the electrolytic capacitors are forward biased with a voltage measurement.

          Glitch

           

          #47718
          quattttro
          BRONZE Member

            If all else fails, verify that the electrolytic capacitors are forward biased with a voltage measurement.

            Thanks. I don’t think the markings are incorrect, I just found them somewhat counterintuitive. Thanks for clarifying. I also found some old pics in the archives that have helped confirm.

            #47717
            quattttro
            BRONZE Member

              I realize that, it’s just that on at least one of these caps, the positive goes to the solid, filled-in side of the label, whereas normally, the solid part of the label indicates negative (-).

              #47719
              Dillen
              Moderator

                The “solid” marking indicates ground.
                That’s not necessarily the capacitors negative pin because some capacitors work with negative voltages.
                The best reference is what the factory fitted (though that is not always guaranteed to be correct either).

                Martin

                #47720
                quattttro
                BRONZE Member

                   

                  The “solid” marking indicates ground. That’s not necessarily the capacitors negative pin because some capacitors work with negative voltages. The best reference is what the factory fitted (though that is not always guaranteed to be correct either). Martin

                  that makes it clear, thanks.

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