9090DB Volume Pot Won't turn off!

Discussion in 'Exclusively Sansui' started by Fhamre, Jul 13, 2017.

  1. Fhamre

    Fhamre Super Member

    I acquired a 9090DB that came with a volume pot that will not turn down the volume fully. No matter how much I tried to clean it,no change. So I replaced it with a donor part and all is well. Now I would like to see if that pot can be fixed. Is it a mechanical issue or?
    Has anyone had success dealing with this issue?
    The volume control portion is the two back portions. Its a 250K pot.
    IMG_7160.JPG IMG_7162.JPG
     
  2. Hyperion

    Hyperion Roobarb & Custard Subscriber

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    Very likely the ground side of one or more of the the tracks is open circuit. This has the effect of changing it from a 'potentiometer' into a 'variable resistor'.
     
    Last edited: Jul 13, 2017
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  3. Fhamre

    Fhamre Super Member

    Can it be repaired?
     
  4. Hyperion

    Hyperion Roobarb & Custard Subscriber

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    Quite unlikely, it might have broken near where the terminal rivet goes through the track, you may even be able to see a crack with an eyeglass. Even if it is only a faulty or corroded rivet, it is fairly unlikely to be fixable.
     
  5. LBPete

    LBPete Rolling Along Subscriber

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    This is a very common issue not limited to any particular model or limited to Sansui. It's been discussed many times over the years. I don't recall if anyone came up with a permanent fix for it because it's really not that big of a deal. Why would you listen to it with the volume turned to zero? Just turn the speakers off if you want to kill the sound output.

    - Pete
     
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  6. Hyperion

    Hyperion Roobarb & Custard Subscriber

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    I think I was assuming it was a bit more serious than just a sniff of audio when turned fully down, simply because of the description of the attempts to fix. :)
     
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  7. Fhamre

    Fhamre Super Member

    Is that a technical term?
    Well I would agree its not the end of the audio world. Just checking to see it there was a relatively easy fix. If not the pot will just sit in my parts box.
    I have read lots of different posts over the years where this issue or a similar one was encountered and attempted repairs made. Will do some more searching.
     
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  8. Hyperion

    Hyperion Roobarb & Custard Subscriber

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    LOL - yeah, best I could come up with. :D
     
  9. Fhamre

    Fhamre Super Member

    Well I like it!
     
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  10. w1jim

    w1jim I can fix it but good... Subscriber

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    Just a guess but I'd think you could take some electrically conductive paint (or the stuff used to fix rear window defroster wires) and use it to jump the open section.
     
  11. moefuzz

    moefuzz Active Member

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    Sounds about as correct as "a gaggle of girls" which I speculate would produce much more than
    just a sniff of audio.


    moe of the north.


    .
     
    Last edited: Jul 14, 2017
  12. restorer-john

    restorer-john Super Member

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    I like the term. :)

    'sniff', however, needs to be quantified to be really useful.

    I am thinking 1 sniff would be equal to the equivalent of the selector crosstalk/coupling you get on a typical receiver from a local FM station when the input or tape monitor switch is pressed with the volume fully up. Some receivers have considerably more than 1 sniff, some have less, some have the proverbial runny nose.
     
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  13. moefuzz

    moefuzz Active Member

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    .



    .

    This post has merit.

    This sounds quite viable.



    .
     
    Last edited: Jul 14, 2017
  14. moefuzz

    moefuzz Active Member

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    .


    ? Original Poster specified Decibels were present at 0 scale on the pot?


    Apparently the knob produced decibels,
    and apparently they were clean dcbls even at zero potency.

    Would that be an unvolume level?



    ????
    A sniff of decibels at some point could become a runny noise?

    or even worse,
    from just a sniff of audio to a river of bad db?
    .

    .
    ?


    .
     
  15. Skywatcher

    Skywatcher AK Subscriber Subscriber

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    Clean the carbon and fingers on the wafer with alcohol and a cotton swab. Wet it with alcohol and work it a few times, then swab it off with clean, dry cotton swabs. Don't "lube" the carbon and fingers. It will help some, but won't completely cure it.
     

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