thrackan

Hi, I have a bit old MZ-G750. When I push the 'rec' button minidisc acts normally, but when I want to play a disc written this way I can hear only silence. After turning it of and on again it shows only 'BLANCDISC' communicate. There are no signs of error communicates on the display. I would be very grateful for info what could be broken in this MD, and what can I do to fix it...