need help, loosing a channel in a mixer.

Discussion in 'General Electronics Chat' started by Roque, Mar 3, 2015.

  1. Roque

    Thread Starter Member

    Sep 16, 2014
    68
    2
    hello to all you tech gurus out there...i have mackie 32.4 vlz pro mixer and i keep loosing one channel ...it just drops out...i use it with a stepdown transformer cause our voltage is 230 and the Mackie is 110v ....the mixer works fine when powered ..then after 30 mins or so ..it looses one channel...any help would be greatly appreciated thanks guys.
     
  2. wayneh

    Expert

    Sep 9, 2010
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    Step 1: Choose a better title to attract someone that might be able to help.
     
  3. Roque

    Thread Starter Member

    Sep 16, 2014
    68
    2
    ok cool ..thanks mate.
     
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  4. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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    First, "need help" is a horrible subject. Some people won't even read your post with a title like that. "Losing channel on mixer" is more informative.

    Second, is it always the same channel that goes out? If so, have you inspected for poor connections, bulging capacitors or anything?
     
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  5. Roque

    Thread Starter Member

    Sep 16, 2014
    68
    2
    how can i edit the title..???
     
  6. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    I can edit the title for you.
    What do you want it to be?

    Bertus
     
  7. Roque

    Thread Starter Member

    Sep 16, 2014
    68
    2
    wonder how can i change that....crazy i am...
     
  8. Roque

    Thread Starter Member

    Sep 16, 2014
    68
    2
    loosing a channel in a mixer.
     
  9. Roque

    Thread Starter Member

    Sep 16, 2014
    68
    2
    thanks buddy
     
  10. wayneh

    Expert

    Sep 9, 2010
    12,156
    3,063
    Nice! Thanks.

    It seems unlikely that power is an issue if the problem is affecting only one channel. Can you describe the problem with more detail? I mean, does it seem like the channel goes out because the board "warms up"? It goes out and stays out until you leave it off for a while? There are cooling sprays that can help diagnose a problem related to heating up. You spray suspected areas to see which spot solves the problem.

    Sorry to ask, but are you certain it's the mixer and not the source(s) or some other component, or connection?
     
  11. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,073
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    @Roque
    It seems like you have a loose solder joint. You could try to re-melt the solder in the path of Channel 1 of your mixer board. Or, better yet, look closely with a magnefying glass at the tracks for Channel 1. Any connections that look weak, cracked, incomplete, or otherwise fishy can be reheated as the first pass. Then do the rest.

    Also look for voltage at/near the output after it failed - it might be a protection relay opening up and the real issue is a short in your output cable or any device downstream that may be drawing too much current (look for a short). (that assumes you have an output for that specific channel and not just mixing onboard).

    Cheers.
     
    Roque likes this.
  12. Roque

    Thread Starter Member

    Sep 16, 2014
    68
    2
    thank you for your reply...yes i tried the mic input and then also the tape in as well..connected my phone and played through the mixer ...after a while ...the left channel just drops of ..when i test it with a mic the left channel goes ..scratchy and the dies of...at times turning it off then on helps but it reoccurs.
     
  13. Roque

    Thread Starter Member

    Sep 16, 2014
    68
    2
    thanks Gopher...the loss is in the left channel the right works fine....when i hit the solo button right left channel works fine..also another thing i noticed is out of the 32 channels number 16 is very faint compared to the rest...
     
  14. Roque

    Thread Starter Member

    Sep 16, 2014
    68
    2
    to make it simpler i meant the left channel ....when i hit the solo switch ..both left and right work fine ..thats whats driving me nuts...:-(
     
  15. Chris-nk

    New Member

    Mar 1, 2015
    19
    2
    Hi! I'm not a mixer expert but I would try to help you.
    Here is a list what would I try to check:
    1. check the input side when the output side turns of. Maybe the input will switch off and so you have nothing on the output.
    2. check the main potmeter maybe it will lose any connection after a while of working.
    3. check the preamp circuit ( find the left - right audio input - output on the datasheet of the IC of the pream or transistor { I don't know how it was build})
    4. check for any cold solderings
    5. check for bad ( bulbed ) capacitors
    6. check the output circuit ( find the left - right audio input - output on the datasheet of the IC of the pream or transistor { I don't know how it was build})
    7. check for any damage on the pcb

    This is what I would do for the first step.
     
    Roque likes this.
  16. Roque

    Thread Starter Member

    Sep 16, 2014
    68
    2
    thanks Chris .will give itt a go this evening...ta
     
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