Tim,

That's exactly what I did after 2 consecutive bad S 900's, but in both cases mine were really messed up. You could see my posting. One had a crack in the back, then the replacement didn't work at all, except for the defaulf piano sound.
I've got my money back. I still like them, but will certainly wait until I hear no more problems with them. I am sure Yamaha must be taking measures to correct all these problems. But by then I might get something else. (PA800 ????) Really like it-but $3000.00 (with the MP3 board)?- I don't know if I can do that.

Thanks,

F. Alberto