Help with Yamaha SY-85 not formatting Disk

by Damien P
(Australia)

Hello !,

Now i know you've probably had this a million times, but i will try to keep it simple.
My "Smart" friend factory reset the keyboard thinking it was factory sound re-instal.
So my FDD in my SY-85 also had a destroyed belt, and i have since then replaced it with a working one.
It reads discs fine.
Did a test on it.
Results of test -
FDD Insert check and it says 1 "OK"
FDD F/W/R "C:40 H1 "OK

They are 720 KB Disks with one hole. 2DD.

When i try to format the disk, it goes from 0% to about 89%, and it seems to almost complete the format.
But at the end of the format it claims *error* "Disk Unformatted" Hit Exit
I'm also using a USB IBM FDD On My macintosh laptop, so it will not read 720kb to format the disk, only reads 1.44mb.

Do you have any suggestion for fixing this issue ?
I was hoping not to switch over to a USB fdd as it loses the originality of it.

Would appreciate any help please !

Damien P

CONTACT ME:
pritcharddamien @ gmail.com