dl111

I have a PX-780M and I have the same issue with one of my lower C and adjacent C# keys. When I press the key softly, it produces a loud buzzing sound, but when I press the key loudly enough, there is no buzzing. While I haven’t been able to actually fix the root mechanical/electric issue, I messed around with the different sounds to bypass the problem. The problem on my piano seems to only occur in the various Grand Piano sound settings (Concert, Studio, Classic). So I simply switch it to the Rock Piano setting each time I turn on the piano and voilà, no buzzing! I know, I know, this should be unacceptable for such an expensive electric piano, but my piano is out of warranty and I’m not holding my breath for Casio to rectify the issue. And except for that one key, I still love my piano 😭. Tbh I seriously can’t tell the difference between the grand piano and the rock piano anyway 🤷🏽‍♂️. Sorry I’m about 4 years late lol but hope this helps.