Mc 303

Hey - I got one of these for free! I actually kind of love this machine, despite the unusable hundreds of preset patterns and only having 50 user patterns.

Now, this unit has a weird problem - the cutoff/volume knob does absolutely nothing, BUT! The LFO knob has somehow taken on the functions of the cutoff knob, so the one knob changes the parameters of both functions, which is of course is super usuable! Things get out of hand real quick! Anyone have any idea what the issue could be? Something I could take apart and remedy relatively easily, or is it worth it!? I mean, it SEEMS like something like that could only happen if someone (for some reason) modded it in purpose!?

Anyway, at the very least its a good sounding VA sound source, it would be cool to get it working

Where are you located?
Maybe someone can point you to a good local-ish repair shop.

Could be a loose knob contact/wire touching what it shouldn’t.

I 'd open it and check for any visible cause around the knobs.