I just purchased a Numark CD Mix 2 CD mixer from Facebook and of course it came with a problem. But that’s ok as it was very cheap.
The issue is during music being played on either CD deck the left channel (left speaker) will cut in and out. Typically this is due to dirty contacts on the crossfader. Given the age of this unit (2001, nearly 20 years old!!) this is what i suspect the issue is.
As you can see i have already begun to take the unit apart by removing all the knobs and also the crossfader unit.
With the top cover off you can see there is a lot going on underneath. Including years and years of dust!
I got to work cleaning out the unit and making all the switches as clean as possible.
So here we have the culprit… The crossfader. This is used to fade between CD deck A and CD deck B while DJ’ing. Naturally, it’s used A LOT and over time this gets full of sweat, dust, food debris.. you name it, it’s likely in there.
Here is an image of one of the volume knobs which is fairly clean dispite some minor corrosion from age. You can clearly see a nice shiny metal plate where the switch runs along and thus produces more or less volume.
Upon inspection of the crossfader however… You can clearly see a nasty black stain where the shiny metal should be. This is all that mess i spoke of earlier mixed together over the last 18+ years – lovely!
While waiting for some contact cleaner to arrive, I’ve begun cleaning up the rest of the unit and repairing these dust protectors for the master volume controls.
After applying new glue where needed i gave the top panel a seriously good clean with surface cleaner and polish.
A bit better, still some marks but these are scratches which unless i repaint it will remain. I’m not going for perfection, just clean and functional.
Afterward I applied a pair of stickers either side of the unit. These are the logo of my favorite DJ and a close friend of mine so I felt it would be nice to apply these to my DJ equipment.
Time to strip down that crossfader…
As expected… Stained and nasty! Though there are actual black covers on the two tracks so they aren’t as bad as i thought. This however…
Really, REALLY bad… let’s get cleaning!
I decided to go with distilled vinegar and a eraser as my contact cleaner still hasn’t arrived. Good old eBay!
Much cleaner and ready to go back together.
Both channels nice and equal now and no issues. Perfect!
Well… or so I thought! After about 2 hours of use the units B deck started playing up and would say no disk or error when trying to play CD’s. The last thing you want to see with something like this…
Needless to say this got really involved and i had to strip the entire thing down.
I cleaned the lens and i also adjusted the pot for the laser alignment. After a 10° adjustment it came back to life.
Thankfully now all is well and it plays Cd’s perfectly once again on both CD decks. The cross fader is also still working flawlessly.
Some nice new nobs for the pitch controls.