Disklavier

Hi there,

I just purchased MX80 with control unit DKC5R, tone generator TG100 
and small accessories. I bought for the piano itself, so there is no 
warrantee on control unit. I'm just trying to work it out by myself to 
play. When I insert a Yamaha disk, it says "unformatted disk". So I 
have found an old 2DD disk and managed to do the formatting for a min 
and says "CANNOT format!". When it gets inserted again, it 
says "CONVERT DISK" Anyone has any ideas how to get this going? I 
heard that it had been sitting for a while like a display model.while. 
Maybe disk drive should be cleaned or replaced?

Any advices will be appreciated.
Thanks