Fixing a Behringer MX8000 desk

Got my mixing desk back from a long term loan and unfortunately  it doesn’t work anymore :/

On power up, there’s plenty of hum coming out of it, flashing input and solo leds, scratchy pots and faders, silent channels, etc….

I guess it’s a power issue, either in the PSU or in the desk itself. Looking at the components, it’s packed with cheap chinese electrolytics capacitors, but apart from those the rest is standard thru-hole resistors, ceramic or mylar caps with NJM 4580 SIP package dual op-amps (still available at mouser).

So my best bet is that some electro caps have rendered their last breath and shorted the rails…

The adventure begins….


3 thoughts on “Fixing a Behringer MX8000 desk

  1. Steve

    I’ve worked on a few of these Behringer boards with the ribbon interconnects. The ribbon cables do get old and for whatever reason they do fail (maybe they oxidize, causing poor connections at the IDC connectors? In any case the insulation becomes brittle).

    I certainly recommend you give them all a good wiggle with the power on and all channels up to see how intermittent they might have become.

  2. Terence Hacke® Post author

    Hi Steve,

    I’ve looked at the connectors but they are ok I think. PSU is ok too .Problem seems more important than intermittent connections.

    I’ve got a big 15V P/P square wave coming from the main board when I press the mix B button on the Phones. Changes frequency as i turn the phone level pot. Makes a great oscillator 🙂

    Also the mono inputs (Right channel) of External and 2 track inputs don’t work. Left channel is ok.

    So far I’ve disconnected the channels boards to try locate the issue so it’s pretty sure the problem lies on the Main board but where?…

  3. Lorne in Canada

    A gentle pass with a hot air gun at about 275 degrees might catch any brittle connect points.
    Brought my nephews emu interface up with that alone.


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