commgrp@silver.ucs.indiana.edu (BACS Data Communications Group) (01/15/91)
Before expensively replacing bad 3.5-inch floppy drives (both 1.44M and 720k) in IBM PS-2 computers, check for this very common problem: Glued to the top of the upper head assembly is an aluminum square, glued in turn to a rubber pad. The glue breaks, allowing the pad assembly to fall down into the space in front of lower head. Result: Drive won't read or write properly because head travel is restricted. Remove upper steel shield: Remove several small Phillips-head screws on each side. Some may be tight due to thread-sealant. Loosen these by tapping gently with a small hammer on the back end of the screwdriver. Loosen circuit board: There are two screws at the back, one on either side. It is not necessary to disconnect wires from the circuit board. Remove the flexible aluminum/plastic shield beneath the circuit board. The head assembly will probably be jammed against the rubber pad. If so, back it up by turning the grease-covered screw-shaft of the head stepper-motor. (I apply rearward pressure to the head assembly, while using a wooden stick (the end of a "Q-tip) to turn the shaft. Retrieve the pad, glue it back in place. DO NOT USE "SUPERGLUE," which is brittle and may break again. Use contact cement or some other type of glue which remains flexible. Reassemble and test the drive. The above procedure worked for six of six drives which I recently repaired. -- Frank Reid reid@ucs.indiana.edu