What if any, is an acceptable resistance here?

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  • survivalbloke
    Badcaps Veteran
    • Aug 2021
    • 290
    • United States
    #1

    What if any, is an acceptable resistance here?

    On this motherboard(and another like it) I'm getting beeps on diode mode at these coils. I posted the resistance readings to ground. At the risk of sounding dumb, shouldn't all coils be OL on my multimeter when measuring resistance to ground?

    https://imgur.com/A0oCmAz
    Tags: None
    • Traceless
      Member
      • Jul 2022
      • 12
      • Germany
      #2
      Re: What if any, is an acceptable resistance here?

      Originally posted by survivalbloke
      shouldn't all coils be OL on my multimeter when measuring resistance to ground?
      https://imgur.com/A0oCmAz
      Undamaged coils will show as a short on a regular multimeter, not open circuit. The resistances you measured there are very likely not the resistances of the coils but resistances of components located between the coils and ground.

        Comment

        • ktmmotocross
          Boardkiller
          • Feb 2014
          • 3586
          • slovakia
          #3
          Re: What if any, is an acceptable resistance here?

          Originally posted by survivalbloke
          On this motherboard(and another like it) I'm getting beeps on diode mode at these coils. I posted the resistance readings to ground. At the risk of sounding dumb, shouldn't all coils be OL on my multimeter when measuring resistance to ground?

          https://imgur.com/A0oCmAz
          resistance on coils is ok. it can go down to 1-2ohm on CPU or GPU main power phase

            Comment

            • survivalbloke
              Badcaps Veteran
              • Aug 2021
              • 290
              • United States
              #4
              Re: What if any, is an acceptable resistance here?

              Originally posted by ktmmotocross
              resistance on coils is ok. it can go down to 1-2ohm on CPU or GPU main power phase
              Much appreciated! I'm trying to hone my board skills more and this helps.

                Comment

                • survivalbloke
                  Badcaps Veteran
                  • Aug 2021
                  • 290
                  • United States
                  #5
                  Re: What if any, is an acceptable resistance here?

                  Originally posted by Traceless
                  Undamaged coils will show as a short on a regular multimeter, not open circuit. The resistances you measured there are very likely not the resistances of the coils but resistances of components located between the coils and ground.
                  Perfect, and thank you. I've got a lot to learn! I got the wrong idea from what I now know as a bad youtube video. I was looking for a fast way to find shorts on a board. Well, not necessarily to pinpoint the short quickly because I would do that with voltage injection and a thermal camera. More like just seeing which power rail the short was on. I was clearly on the wrong track lol.

                    Comment

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