Floppy Drive not responding on a Korg PA50

[Shazb]

Hello All, I just found out that the floppy drive on my Korg PA50 is not working. Here is what is I have done.

Used three different 3.5" 1.44mb HDD disks, formatted on Windows XP System and MSDOS 6.22 system.

Korg does not format and does not see the disks. It displays an error that it encountered Generic Error and No Disk/Unformatted Disk. But everytime I try to perform a function, the light goes green so I think the signal is working.

If someone can answer the following:

Is the formatting I am doing not correct?
Could the Read/Write Head be defective or dirty?
Do I need to replace the drive? and if I do is it just a generic floppy drive?

any help will be appreciated.

Thanks