# Cleaning Pots on Sound Board



## JimP0771 (Feb 25, 2017)

Hi All

I have a Mackie VLZ 24-4 Mixer that when I move some of the gain pots around you can hear scratchy noise. I was wondering if anyone has any advice on how I can clean the gain pots. I have taken off one the the gain pot knobs and there is no way to get down in the workings of the gain pot nob. I know some sound boards have little holes that allow you to squirt little bit of cleaner in to the pot inner workings but I do not see that on the Mackie Board. 

Any advice would be appreciated.


Thanks


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## Footer (Feb 25, 2017)

http://store.caig.com/s.nl/sc.2/category.293/.f 

Spray some in it, it'll make it to where it needs to be.


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## dmx (Feb 25, 2017)

Footer said:


> http://store.caig.com/s.nl/sc.2/category.293/.f
> 
> Spray some in it, it'll make it to where it needs to be.



+1 for DeoxIT


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## TimMc (Feb 26, 2017)

Caig Labs De-Oxit is the primary chemical to use, but don't spray it down the potentiometer shaft as that will just flush the viscous damping (silicon grease) down onto the resistive element. You will need to access the "can". Note that some of these controls also have conductive grease on the resistive element and the cleaner will flush that out as well.

If you desire a lasting repair you should replace the pots. Cleaning without disassembling the pots is at best a transient fix.


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## Footer (Feb 26, 2017)

TimMc said:


> If you desire a lasting repair you should replace the pots. Cleaning without disassembling the pots is at best a transient fix.



Its a mackie 24 channel VLZ, if it is still running its a small miracle... and some would argue this desk itself is a transient fix. 

@JimP0771, if you do find this does not fix it, don't pay for the repair. Save your pennies and buy an X32.


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## TimMc (Feb 26, 2017)

I wasn't going to go there, but I certainly agree with your assessment.

Footer said:


> Its a mackie 24 channel VLZ, if it is still running its a small miracle... and some would argue this desk itself is a transient fix.


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## JD (Feb 26, 2017)

Be aware that the pots get hooked on the stuff. 
There are two reasons pots get noisy:
1) dirt on the resistive trace / oxide on the tapper brush.
2) The trace is worn away / brush is worn off.
Running the pot back and forth about 20 times between it's extremes can clean it up a bit if it is impractical to clean as long as it is #1. However, years of a "very active" mix can actually wear the carbon trace through to the non-conductive backing. In those cases, replacement is the only option and may be cost prohibitive.


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## MikeJ (Feb 28, 2017)

I'm pretty sure all of those pots are PCB mounted, then the shaft of the pots go through the holes in the metal case, and EVERY ONE has a nut screwed down on it. You have to remove every knob, and every nut. If the fader cleaner does not work, its pretty much not worth the labor to repair.


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## RonHebbard (Feb 28, 2017)

MikeJ said:


> I'm pretty sure all of those pots are PCB mounted, then the shaft of the pots go through the holes in the metal case, and EVERY ONE has a nut screwed down on it. You have to remove every knob, and every nut. If the fader cleaner does not work, its pretty much not worth the labor to repair.


And that's why God invented hollow-shaft nut drivers.
Toodleoo!
Ron Hebbard.


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## JD (Feb 28, 2017)

MikeJ said:


> I'm pretty sure all of those pots are PCB mounted, then the shaft of the pots go through the holes in the metal case, and EVERY ONE has a nut screwed down on it. You have to remove every knob, and every nut. If the fader cleaner does not work, its pretty much not worth the labor to repair.


It only seems like a monster task until you've done it a few times. I remember popping over 100 off a board once. Timed it. Took about 25 minutes. In the grand scheme of things, it's not as big a deal as it looks, just a LOT of boring repetitive motion. Still, I wasted 25 minutes on worse. (a reinstall of Windows today comes to mind.)


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## MikeJ (Mar 1, 2017)

JD said:


> It only seems like a monster task until you've done it a few times. I remember popping over 100 off a board once. Timed it. Took about 25 minutes. In the grand scheme of things, it's not as big a deal as it looks, just a LOT of boring repetitive motion. Still, I wasted 25 minutes on worse. (a reinstall of Windows today comes to mind.)



Yeah, so true. I guess it depends on the individual situation. If it's my board, and it does everything I need it to, I might spend the time to do the repair. If I could not do it myself, and was itching for something new anyway, the labor cost sending it out would probably be better put towards something newer and better.


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## TimmyP1955 (Mar 21, 2017)

CRC QD Electronic Cleaner (does not leave a mess like DeOxIt). Sometimes you can get lucky and it will run between the shaft and the bushing and get the pot cleaned up. If not, time to take it all apart as was mentioned above.


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## venuetech (Mar 21, 2017)

RonHebbard said:


> And that's why God invented hollow-shaft nut drivers.


No, That's why god invented dumpsters. That's where i keep my SR32-4. I'm sure it will be there when i go looking for it.
My De-Oxit budget was getting out of control.

but you can try just exercising the pot as JD suggests in an attempt to clean off the oxidation.


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