SMD capacitors?

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  • dds
    New Member
    • Feb 2008
    • 7

    #1

    SMD capacitors?

    How can I test them on pcb?
  • PCBONEZ
    Grumpy Old Fart
    • Aug 2005
    • 10661
    • USA

    #2
    Re: SMD capacitors?

    You test them the same as other caps.

    .
    Mann-Made Global Warming.
    - We should be more concerned about the Intellectual Climate.

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    Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.

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    Comment

    • starfury1
      Badcaps Legend
      • May 2006
      • 1256

      #3
      Re: SMD capacitors?

      capacitance meters are designed to test on board...they use low AC frequency
      if I remember correctly

      of course to be absolutely sure it best to remove, but SMD is a bit of a pain
      so best is "If in doubt replace"
      (if you dont have proper removal tool 2 irons can do the job)

      larger electrolytic type tantalum ones are prone to failure (+ on them in uf range)
      smaller ceramic types will mostly probably be ok
      but all caps can fail
      (and there has be cases of them cracking there ends off due to stress)

      welcome & cheers
      You step into the Road, and if you don't keep your feet, there is no knowing where you may be swept off to." Bilbo Baggins ...

      Comment

      • dds
        New Member
        • Feb 2008
        • 7

        #4
        Re: SMD capacitors?

        Can I get some recommedations for a good Capacitance meter?
        I have a Extech RC100 SMD capacitance meter which is totally unreliable
        for in circuit measuring (works fine outside circuit with smd capacitors)

        Thanks
        Last edited by dds; 02-22-2008, 10:28 AM.

        Comment

        • PCBONEZ
          Grumpy Old Fart
          • Aug 2005
          • 10661
          • USA

          #5
          Re: SMD capacitors?

          SMD are measured the same as other caps.

          If it's in the circuit and there are other caps in parallel either directly or indirectly then in-circuit testing won't work.
          - There are usually other capacitances in parallel in-circuit.

          That's probably what your problem has been.
          Not the meter.

          .
          Mann-Made Global Warming.
          - We should be more concerned about the Intellectual Climate.

          -
          Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.

          - Dr Seuss
          -
          You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
          -

          Comment

          • dds
            New Member
            • Feb 2008
            • 7

            #6
            Re: SMD capacitors?

            Originally posted by PCBONEZ
            SMD are measured the same as other caps.

            If it's in the circuit and there are other caps in parallel either directly or indirectly then in-circuit testing won't work.
            - There are usually other capacitances in parallel in-circuit.

            That's probably what your problem has been.
            Not the meter.

            .
            Thanks for your reply. But I'm more confused, how can I reliable measure capacitance in circuit?

            Comment

            • PCBONEZ
              Grumpy Old Fart
              • Aug 2005
              • 10661
              • USA

              #7
              Re: SMD capacitors?

              I don't know what you don't understand.

              If there is nothing in parallel then you put a lead on each end and measure it.

              If there is something in parallel you remove at least one end from the circuit and do the same thing.

              .
              Mann-Made Global Warming.
              - We should be more concerned about the Intellectual Climate.

              -
              Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.

              - Dr Seuss
              -
              You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
              -

              Comment

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