Fixing a Behringer MX8000 desk (3)

Some more advancement on  the mixing desk front…

Replaced the NJM4580 I thought was the culprit and no changes. gah

I also made a new cable that connects the main board and the input board but it’s not that either.

Next plan is to change the two 2SC2878 responsible for the muting of the Mix-B channel. I read on a HiFi forum that when they fail they put DC in the audio path. Sounds like my problem….

So I ordered some and waiting again for delivery.

Next things to fix / restore are:

– a dead channel on one of the voice boards.

– a deep clean up of all the sliders. They are filled with dust and gunk. yak

– Find a way to restore the color of the knobs. they all gone yellow and the grey ones are in the same state. Peroxide + UV treatment ahead…

– Get the whole thing back together. hm, hope i will remember what screw goes where… The damn thing has been sitting on my dining table for more than a month now…

And it will be done i think


3 thoughts on “Fixing a Behringer MX8000 desk (3)

  1. Michael


    did you come along with repairing your MX8000? I have the exact same problem right now. I disassembled the unit so that I only have the master board connected with the board where the phone inputs are located (and power of course). If I select “Mix-B” as source for the headphones, turning the knob a little gives some pumping noise which will get faster and louder the more the pot opens. Did you change the two 2SC2878? Did it work?

    Best regards

    1. Terence Hacke® Post author

      Hi Michael,

      I did change the 2SC2878, but it didn’t do anything. The problem isn’t really one as it disappears when you put the board back in the case. The master board needs to be grounded to the chassis. In fact i’ve searched for that problem for weeks and it was just that i had removed the boards from the chassis for cleaning/testing. I still have to fix some stuff on mine, flashing input leds and a dead channel.

      1. plugenpay


        I have simular issues with the MX8000. The green leds of all channels (-20db) are blinking random and I measure ground bounce, spikes on the digital ground w.r.t. analog ground.
        Does that sound familiar?
        Any solution available?

        Regards, Wim


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