Disklavier

Hi,

Experienced something unusual yesterday:

1. My disklavier would play a song or sometimes a few songs from the 
floppy and stop thereafter, and the LCD shows "PIANO POWER OFF! <PWM 
OVER>"

2. After the above happens, when I press 'STOP' to clear the message 
and plays another song, I can see from the LCD that it is playing, 
but in the silent mode and the keys are not moving.

3. If I Power Off the piano & Power On again, then it plays 
normally...but the error repeats.

4. Also saw another error message once "SILENT MUTE PEDAL ERROR".

Would really appreciate it if someone can help to explain why this 
is happening.

Understand there's a "RESET" function, which will restore the piano 
to factory default settings. Would this help?

Thanks.