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Testing a PSU out of Gulbransen

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  • Testing a PSU out of Gulbransen

    I pulled a PS out of an equinox 2 organ, but I don't know if you are supposed to test it out of the unit or while it is in there...

    How do I test it? well I put the little probe thingy on the outpins to the ground..(which ground case or supply? I would say case)

    I found a bad GAK thyristor on the lesile board and have ordered a new one.

    I notice that it looks like someone has put a grounding jumper between the switch plate and the right control switch board, and there is clipped ground wire lug on the reverb case.

    I think Ill wait until I get the leslie board back together, then start from there...

    Again, I need to know if I am supposed to test the PS out of the machine or while it is hooked up.
    Anybody please..

  • #2
    power supply voltages.

    I don't know.... this is my first power supply.

    Is it(the VOM meter?) supposed to read the voltages without the ground probe attached?


    There is an on/off switch in the case it(the power supply) came out of.... Am I supposed to jumper the pinouts in the plug that comes from the case, to turn it on first?


    • #3

      You might get more responses if you tell us what organ you have (not all are the same), and keep your posts regarding your organ in 2-3 threads instead of beginning a new thread for each one.

      Meanwhile, I'll call attention to your post with a couple of techs on the Forum. Hope this helps.

      Way too many organs to list, but I do have 5 Allens:
      • MOS-2 Model 505-B / ADC-4300-DK / ADC-5400 / ADC-6000 (Symphony) / ADC-8000DKC
      • Lowrey Heritage (DSO-1)
      • 11 Pump Organs, 1 Pipe Organ & 7 Pianos


      • #4
        Any voltage reading requires that the meter be connected to the voltage and to ground--the ground should be the power supply ground (sometimes called 0 V for Zero Volts), and not the ground (or earth) connection of your AC source. It's usually fine to test the supply in the organ without disconnecting anything.

        Note that the only time you would not ground a connection is when the tech info for the specific item you are testing says to do that. The only instance I know of this was the Rodgers core memory combination action.