Apple 9500/132, 9500/200, 9500/180MP, 9500/150 manual

	Troubleshooting		Symptom Charts/Floppy Drive - 16
Internal floppy drive		1	Replace disk with known-good floppy disk.
runs continuously		2	Replace floppy drive cable.
		3	Replace floppy drive.
		4	Replace processor card.
		5	Replace logic board. Retain customer's DIMMs. Note: When
			you replace the logic board, be sure the LED cable is not
			interfering with the power actuator.

MS-DOS drive does not recognize a disk formatted on a 1.4 MB drive

To read and write files with either MS-DOS or 1.4 MB drive, format all disks with MS-DOS drive first.