Hello, I'm happy to have found this informative forum.
Hopefully you can help me. My 460 is a mere 14 hours old in my household. I am thrilled with the excellent tones, feel and "acoustics" of the instrument, it feels like a wonderful no maintenance replacement for my aging upright.
One problem, one that my troubleshooting abilities have sourced, but I need to know the recommended course of action. E in the octave above middle C creates a harmonic buzz, like metal rattling but at a very high frequency. It is definitely harmonic, as the octave below produces it to a lesser extent, but other notes in the harmonic range will contribute as well. Yet if I play something in D-major, it is non-existent. Listening at close range under the piano reveals it is not that speaker, it is definitely the in-cabinet speaker as placing my ear against the "wood" in the back clearly identifies the geography of the source. Do I open up the cabinet and merely tighten a speaker, or do I tell Casio I'm not happy?