Dsl40cr Intermittent Volume Cutout

Discussion in 'Marshall Amps' started by Bjornson18, Feb 12, 2019 at 9:45 AM.

  1. Bjornson18

    Bjornson18 New Member

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    Hello,

    I'm playing on a Marshall DSL40CR on the OD2 channel with the channel LED indicator red and footswitch plugged in. Once in a while the amp will simultaneously drop the volume to zero, the LED channel indicator on OD2 turns green, and the volume and footswitch are unresponsive.
    It's happened twice now, and it will fix itself if I completely shut down the amp and restart it.

    Does anyone have any idea what this could be?

    Thank you!
     
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  2. Mal

    Mal New Member

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    Sounds a bit like the mg series problem with head phone socket bypass connection clagging up with carbon or not making good connection. Try plugging and unplugging a jack in the headphone socket
     
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  3. Bjornson18

    Bjornson18 New Member

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    You think the amp is bypassing output to the speaker to the headphone output? I'll give it a try, thanks.
    But why would the footswitch quit?
     
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  4. Mitchell Pearrow

    Mitchell Pearrow Well-Known Member

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    Welcome to the forum, there is a dedicated thread for your amp, you will get far more, traffic and responses in the official dsl40cr thread! Cheers new brother
     
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  5. Mitchell Pearrow

    Mitchell Pearrow Well-Known Member

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    Mal if I have already said this please disregard, but welcome to the forum new brother! Cheers
    Mitch
     
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  6. Mitchell Pearrow

    Mitchell Pearrow Well-Known Member

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    Check out the dedicated thread is on page 6
     
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  7. SkyMonkey

    SkyMonkey Member

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    Is this the original 2 button footswitch?
     
  8. ampmadscientist

    ampmadscientist Well-Known Member

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    Welcome to the forum Bjornson.
     
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  9. Jon C

    Jon C Well-Known Member

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    Are those a MultiVolt IC switching design AMS ??
     
  10. ampmadscientist

    ampmadscientist Well-Known Member

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    "Once in a while the amp will simultaneously drop the volume to zero, the LED channel indicator on OD2 turns green, and the volume and footswitch are unresponsive."

    A. That would indicate that this is not the headphone jack problem.

    The channel switching is accomplished by IC 4 (AT2313). This IC operates on 5 VDC.

    DSL40C5V.png


    DSL40Cswitching.png
     
  11. Jon C

    Jon C Well-Known Member

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    @Bjornson18 .. what Amp Mad Scientist posted is what controls how your Footswitch Presses should change channels and stuff …… The Footswitch could be to blame or the IC ( Integrated Circuit ) could be to blame … even the Jack where you plug the Footswitch In being dirty could be to blame ……
    He has actually provided you with the Official Service Tech recommendation ……
    Make sure that 5Volts DC is present at the Amp's Footswitch Plug
     
    Last edited: Feb 13, 2019 at 9:48 AM
  12. SkyMonkey

    SkyMonkey Member

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    Are the switching circuits the same for the CR? Those schematics are from 2011, for the DSL40C.
     
  13. Jon C

    Jon C Well-Known Member

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    May be different due to the additional IC for MIDI but the concept is the same …… Multi Volts ranges triggered by The Footswitch for the IC to see
     
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  14. SkyMonkey

    SkyMonkey Member

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    I see. Schematics are still thin on the ground for the CR, so good to know.
     

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