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Ashly GQX 3101 31 Band EQ Restoration

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    Ashly GQX 3101 31 Band EQ Restoration

    Hello there,

    Since i am new to this forum, and i thought that i want to share a little bit of my experience restoring this Ashly GQX3101 EQ. The original owner is happen to be Goverment of Malaysia , and by specifically owned by gov school at my area since 1993 . This problem with this EQ , its cannot detect any input signal from all the jack / port available.In order to fix this, i had googled the service manual / any schematics available to fix this problem.For almost 4 years i tried to find both of the documents, and guess what? i got nothing. One week before, around 21 / 05 / 2013, i random watch youtube videos about electronics ( * since i am abducted with electronics and currently now taking diploma in electronics engineering (computer ), now in last semester ( sem 6 ), i found one great channel , username " Maxxarcade ", i and had almost learn everything that basic electronic which i had never learnt during my diploma.He also make me inspired to repair back this EQ after 4 years.Since Ashly had discontinued production of this unit,to try my luck, i had contacted Ashly technical person, named Jim Schwenzer asking for schematic.In my mind, i just thought that i would possibbly waste my time asking for schematics since i cannot found anywhere on the net.
    Just a few minutes after i send the email, Jim had replied my email with the schematics and also few problem that maybe connected to the problem.Initially, i thought the op amp was broken / damaged .Since i had test at diode at the voltage regulator, i got -18V at 7818 negative voltage regulator and 0V at the 7918 voltage regulator.After searching around the board doing some checking at the Electrolytic cap, they all seems fine.Rubycon brand.
    Guess what happened?
    The polyster film capacitor 0.1uF had caused the problem.Even though the EQ can be powered on, the "shorted" capacitor had caused the 7918 positive voltage regulator reads 0V instead of 18V as it should be.

    After replacing the "shorted" capacitor, the EQ now runs smoothly without any other problem and sounds perfect !.

    And, i want to thanks " Maxxarcade " for uploading such a educational video even though he just said its for fun . You had saved my day ! Thanks again. Not forget, Jim Schwenzer from Ashly Technical Service for the schematic and tips.


    I had attached the schematic of Ashly GQX3101 schematic if anyone else had this EQ for repair or future reference can used it at ease.Sorry for my broken English. I hope you guys dont mind.Thanks again.


    Attached Files
    Last edited by 9w2tzw; 05-27-2013, 05:58 AM.
    Learn a Little but Often,
    Practice Makes Perfect,
    Repetition is the Key of Success,

    #2
    Re: Ashly GQX 3101 31 Band EQ Restoration

    Great to hear! It is unusual to see polyester cap go short.

    Only one correction: 7818 is positive, 7918 is negative.

    It's nice when manufacturers provide schematics -- most of them closely guard them as secrets! I think schematics should be provided for all electronics after warranties expire.
    Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
    For service manual, schematic, boardview (board view), datasheet, cad - use our search.

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      #3
      Re: Ashly GQX 3101 31 Band EQ Restoration

      Originally posted by tom66 View Post
      Great to hear! It is unusual to see polyester cap go short.

      Only one correction: 7818 is positive, 7918 is negative.

      It's nice when manufacturers provide schematics -- most of them closely guard them as secrets! I think schematics should be provided for all electronics after warranties expire.
      yeah.sorry for that.my mistake

      firstly i just thought the electrolytics had gone bad, but it appearently to be opposite.anyway, i too happy this week since it came back to life.

      Learn a Little but Often,
      Practice Makes Perfect,
      Repetition is the Key of Success,

      Comment


        #4
        Re: Ashly GQX 3101 31 Band EQ Restoration

        C302, the blue one, looks "suspiciously" like a ceramic, not a polyester cap. It's too small

        And ceramics HAVE been known to fail shorted...
        Khron's Cave - Electronics - Audio - Teardowns - Mods - Repairs - Projects - Music - Rants - Shenanigans

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          #5
          Re: Ashly GQX 3101 31 Band EQ Restoration

          Originally posted by Khron666 View Post
          C302, the blue one, looks "suspiciously" like a ceramic, not a polyester cap. It's too small

          And ceramics HAVE been known to fail shorted...
          Yes it is a multilayer ceramic capacitor. Like these, but colored blue instead of yellow in the image.

          Multilayer ceramic capacitors are more prone to cracking inside, causing short circuits.
          Muh-soggy-knee

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