How did this work out?
I just got an MZ NH700 that's not reading my MD's correctly.
Sometimes it even says "NO DISC"
I think the previous owner messed with it because in the service mode it says
005
Ver 1.200
I've checked with http://forums.sonyinsider.com/topic/11021-entering-service-mode-on-a-hi-md-player/ and there it says 'ver1.100'