I think there is a demo button (I think U hold auto-tune while powering up)... make sure u check everything (NON calling u stupid... sometimes we forget what's more obvious... happend 2 me couple of times )... cables power suply, connection 2 the mixer, headphones, volumes, midi leads, etc... MIDI CHANNEL... plug another machine on the same lead and make sure it's receiving midi... try the all key range.. open the filter cut off... I had one so many years ago .. but I really can remember any particular probs with it!?!

Z