Mixing-console faders and potentiometers can gather dirt and dust that can decrease signal integrity or reduce physical operating smoothness. Clean faders and pots can be achieved with simple steps, but if the dirt and dust is substantial, you will need to use more involved methods.
Blow out the faders with compressed air. This is often the only step that will be needed, as the problems with your faders and pots may only be caused by dust. Move the fader to one end and blow away from the fader, then move the fader to the other end and repeat.
Spray contact cleaner into the fader module if compressed air didn't provide a satisfactory result. Just as with the compressed air, move the fader to one end and spray a light coating of contact cleaner into the fader module. Move the fader from end to end to work the cleaner into the module, and the blow out the fader with compressed air again to spread the cleaner thin.
Add lubricant to the module if the compressed air and contact cleaner still didn't provide satisfactory results. Use a precision dropper full of lubricant to place a very small amount of lubricant in the fader module. Move the fader from end to end to work the lubricant, and then blow out the fader once again with compressed air. This will spread the lubricant thin, which is important as lubricant can collect more dust.
If compressed air, contact cleaner and lubricant still fail to produce smoothly working faders and potentiometers, you may have to completely rebuild, or consider replacing, your modules.