Behringer MX-3282a and power supply help

[hijacker]

Hello All,
I have a Behringer MX-3282A mixer and power supply,
the mixer has a dead channel, I was looking at the power supply and found that the 17volt negative voltage regulator looks like it is burned, the regulator resistor has turned brown from over heating. I think that I will change out both the positive and the negative voltage regulator transistors and the related resistors in that circuit. Can I power up the power supply without connecting it to the mixer to check the voltages on the connector plug? Sure could use some help here.
Hijacker

[mozwell]

Yes, its ok to run the linear regs with no load.
I am not familiar with these desks, never having opened one up, when the regs have been removed, measure with an ohm meter across teh power rails to 0V, there must have been some fault causing the reg to blow up, We need to find that & correct it before we power up again.

[hijacker]

Could something be wrong in the mixer to cause the power supply to burn out the regulators? Should I be looking in the mixer for burned components? I can't imagine the voltage regulators to run hot and burning out. Just a question.
Hijacker

[Enzo]

You have one dead channel, but the rest work? If the thing works at all, then your power supplies are probably fine.

You should be looking for a bad op amp, a bad insert jack, a bad fader.

[sidiri3561]

sorry to bring up an old post my question is for anyone out there Im a rooking so I really dont know how to operate any board at all, but I got a Eurodesk 3282a and it seemed to be working fine, it really did sound great, but from one day to another, I plugged everything in normally, started playing, and all of a sudden the sound cut out, the board didnt loose power, everything remained working, but it just hummed, I powered it down and then restarted it and it worked fine, a few minutes later it did the same thing? could anyone help me or give me any advise besides purchasing a new one

[km6xz]

Does is happen to just one input channel or all of them? Isolate the problem by routing the signal through other channels, and different busses. The most common cause of intermittent is oxidation on insert jacks. They should be deoxidized every 8-12 months anyway to prevent that, and it occurs most on channels or mains which have nothing plugged into their inserts most of the time. One common complaint is the sound breaks up with a signal and becomes most upper frequency, and distorted or cuts out completely intermittently.
Use a good deoxidizing chemical like Craig Labs D-5 or Cramolin Contact Clean. A tiny amount sprayed into each insert and then using a 1/4in phone plug to insert and remove several times, then go onto the next insert. It is not dirt, so do not use a cleaner, but a deoxidizer.

[sidiri3561]

it seems to only be happening on the main L/R outputs, I did isolate all other channels individually with all inputs down except the one I was testing and sure enough a a minute - two minutes at the most, the sound cuts out and it just starts to hum, if I bring the main L/R down all the way the hum stops but as I raise them again the hum begins I shut the board off and power back up and it work normally one or two minutes and then it does it all over again with every channel,