Technic GN3 Organ 3 1/2 floppy drive will not read 720mb DD disks

Using original type disks, DS,DD,720MB new and old. Formatted new disks on a 720mb drive and loaded start setup software using all versions of Windows OSs. Setup software is using DOS OS. 90 out of 100 tries of load sequence will fail to load at startup, rarely will load correctly. All disks load properly on different drives. Red light will turn on and disk will turn momentarily and then stop with "NO DISK" indication on organ. Disassembled Technics-Matsushita SY-FD20 drive, cleaned heads, no mechanical resistance of drive and mechanism. Replaced drive belt with new identical and tighter belts. No slippage.  Drive not accessable inside ORGAN enclosure. Cannot extend outside organ to observe. Flat 22 conductor male connector not available for extension outside of organ for troubleshooting. Not compatible with any standard PC components. 22 pin Connector is 2 1/4" (57MM) wide. with 2.3MM flat conductor spacing. Board thickness 1.6MM. Cannot find Technics, Panasonic, Matsushita SY-FD20 drive on Internet. This Technics GN3 organ is about ten years old now and needs setup files to work properly for different musical instruments. My next plan is to get it to work with the MIDI input interface installed if I can't get the floppy to work without schematics. I would appreciate any help or suggestions. Thank You.