Make sure:
1. Mic is on
2. Mic/cable work
3. Mic is plugged into correct input
4. Mic gain knob is set above zero
5. When you press MIC SETTING, make sure that MIC MUTE is not set to ON(Lower right hand corner).
If you have followed all of these steps and you still don't have sound, then you have a broken PSR2000.
Beakybird