#1
Hello,
I've volunteered fix the school's mixer. I had already created a thread about cleaning the faders. I cleaned them all. It's working.

But now I've run into a problem, the Left or Right side becomes very quiet after a little while. I know for sure this is the mixer doing this.
I switched to a Sub out and it was still the same way. Turning the power off then on fixed it... Temporarily. Next time it happens, I'm going to use an Auxilllary out and see if it's the same way.
I'm not sure what's going on here. When I Solo the channel it shows both left and right signal going through.
It does this on every channel.

The mixer is a Mackie SR32.4 VLZ Pro.
Any help would be greatly appreciated.
--timbit
..I was watching my death.
#3
If its fine at first, then the volume drops after awhile, likely a capacitor.
And being that its common to every channel, its likely something to do with the power section.
Look for capacitors that have bulges.


Edit:
This one is fine, but look for bulges at the top.
Last edited by CodeMonk at Apr 18, 2011,
#4
Alright. I most likely am not able to check it out untill next weekend.
I've read that it could be something to do with the ribbon cables as well, but I reseated all the channel-related ones. But that doesn't explain the dying after a while.

Capacitors definately do make sense, if I turn it on and off, the caps would be charged again.
My problem with checking the caps though, the caps are all micro caps. Some of the caps in the power section may be regular.
How do I tell if a micro cap is dying?

EDIT: Would it possibly be a filter cap? I think these ones are normal sized in the mixer.
I'll check just the power section at school tomorrow, there's not enough time in one class to take out all of the allen bolts(There's about 40-50) that hold the PCB in.
..I was watching my death.
Last edited by timbit2006 at Apr 18, 2011,
#5
If it was a capacitor in the power section,
Why would only the left channel go quiet?
..I was watching my death.
#6
The capacitors in the Power section of the mixer are regular sized.
I looked in the mixer and found one capacitor in the power section that was leaking majorly. The top was bubbled up like Codemonk described. I still need to check on if there is anything on the main PCB's. Hopefully there isn't.
I'm able to fix the mixer tomorrow.
I will replace all the caps in the power section as I am not paying for this and when one is going to go, the rest will be soon after.

I'm still not sure why it only occurs to one channel though, I guess I'll call Mackie and ask for a schematic, unless I can find one online.
Thanks for your help Codemonk.
..I was watching my death.