Left side lows and LPF/HPF knobs just stopped working

Currently taking a class where they are teaching DJ skills using the MC4000. Everything was going great. Day 5 into the 10-day class turn on the unit and the left side lows and LPF/HPF filter knobs no longer work. Tried moving my unit to another computer and no luck. Then borrowed someone else’s unit and theirs worked fine so I know it wasn’t a setting on my computer. I’m concerned the hardware failed. That’s weird since the unit is only 5 days old and has never been moved from its original position.

Does anyone have an idea what would cause something like this?


Hi! Happy to help!

You could run a quick test with a MIDI monitor and that should tell you if the knobs are still working or not. If the MIDI monitor sees anything come in when you turn the knobs, they’re not broken.

That said, I suspect the test with MIDI monitor may be unsuccessful. One of our Tech Support agents will reach out to shortly to connect and troubleshoot further. They’ll be able to assist within any warranty service if necessary.

I hope this helps!

You are correct. I ran the MIDI Monitor and got nothing on those particular knobs. Now I guess I will await contact on how to get a warranty repair done.