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Trouble With Poor Man's foldback

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  • Trouble With Poor Man's foldback

    Hello, i'm working on first mod of my m3. I'm doing the poor mans fold back based on this video https://www.youtube.com/watch?v=LRp95Wr3Rmg . I've run into a problem. My multi meter isn't picking up anything when I press keys and try matching wires. Does it matter what position the drawbar is in. I'd assume percussion must be off. Is there any other way to know which wire goes to which terminal? Is it possible that there is no continuity and that's why I can't get anything. I'm a little eager to put this thing back together. I've been stuck on this for longer than I'd hoped. Any advice helps. Thanks.
    M3 w/ Field Coil
    M111A 1967
    M2 (Gone)
    Leslie 125 W/ Amp 1963

  • #2
    Drawbar setting shouldn't matter. Are you using the correct multimeter setting (ohms, or "continuity beep" if your meter has it)?
    Current organs: AV, M-3, A-100
    Current Leslies: 22H, 122, 770

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    • #3
      It's set to continuity beep and I tested it. It worked elsewhere.
      M3 w/ Field Coil
      M111A 1967
      M2 (Gone)
      Leslie 125 W/ Amp 1963

      Comment


      • #4
        Originally posted by antrider85 View Post
        It's set to continuity beep and I tested it. It worked elsewhere.
        OK. Keep in mind though - you're not supposed to see zero resistance. The resistance wires are 16 ohms, and the rest of the circuit also contributes some - so depending on your meter's limit for what it considers "continuity", it might not beep. Have you tried in the Ohms range, looking at the meter instead of listening to it?
        Current organs: AV, M-3, A-100
        Current Leslies: 22H, 122, 770

        Comment


        • #5
          The continuity beep on digital multimeters can do more harm than good. The display typically gives a dubious reading, and most users don't really know what resistance the meter does or doesn't beep at.

          Except when ringing out extension cables, it's best to do an actual resistance check.

          Comment


          • #6
            Originally posted by antrider85 View Post
            It's set to continuity beep and I tested it. It worked elsewhere.
            Originally posted by enor View Post
            OK. Keep in mind though - you're not supposed to see zero resistance. The resistance wires are 16 ohms, and the rest of the circuit also contributes some - so depending on your meter's limit for what it considers "continuity", it might not beep. Have you tried in the Ohms range, looking at the meter instead of listening to it?
            Yep... I was fooled by this when troubleshooting a guitar amp reverb. Thought the meter would beep at any reading other than a fully open circuit.... not the case.
            60' Hammond A-100 (free!) Church duty, certainly not "minty"
            Leslie 710 ($80)

            Comment


            • #7
              I'm away from my organ right now, but are you saying that I should only receive signal from the wire that I am matching to a note?
              M3 w/ Field Coil
              M111A 1967
              M2 (Gone)
              Leslie 125 W/ Amp 1963

              Comment


              • #8
                No, you shouldn't expect signal. What you should look for is "sort-of-continuity" to ground on the corresponding wire when you depress the key in question.
                Current organs: AV, M-3, A-100
                Current Leslies: 22H, 122, 770

                Comment


                • #9
                  Thanks for your help. I’m still struggling a bit to understand this however. So should my multimeter just be set to ohms or something else? Currently on either ohms or continuity beep the multimeter just reads blank when I attempt to match the notes and wires. Even if I touch one wire to the multimeter and hold down all keys I get nothing. How do I look for “sort of continuity”?
                  M3 w/ Field Coil
                  M111A 1967
                  M2 (Gone)
                  Leslie 125 W/ Amp 1963

                  Comment


                  • #10
                    Resistance is the opposition to the flow of electric current, measured in Ohms. When your meter is in the "Ohms" range, it displays a value between zero ohms and infinity (or at least some amount above the range your meter can measure).

                    Touch the meter leads together. The meter should read zero ohms, or something very close to zero due to the resistance of your meter leads. Take one meter probe in each hand and squeeze the leads with your fingers. You should be able to make the meter read some number which you can change by squeezing more or less. If not, something may be amiss with your meter.

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                    • #11
                      Based on what you described my meter is working properly. Is there any other reason my meteter would read no resistance on any of the wires?
                      M3 w/ Field Coil
                      M111A 1967
                      M2 (Gone)
                      Leslie 125 W/ Amp 1963

                      Comment


                      • #12
                        Well, no resistance means you have a complete ("short") circuit. What I suspect you are measuring is very high resistance. In that case, I can only guess that you are measuring the wrong points: there is no circuit that you are measuring. Beyond that, there's not much I can do from here.

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