Abstract: Methods and apparatus are disclosed determining the presence of base line popping noise for a read head inside an assembled disk drive, as well as, determining read bias conditions for operating the read head free of base line popping noise. These further include performance evaluation of the read head for read bias conditions free of base line popping noise. They also include repairing the read head using DC write current and read bias current within the assembled disk drive.

Abstract: An acoustic plug for an acoustic plate that is attached to a cover of a hard disk drive. The hard disk drive includes a disk that is attached to a spin motor. The spin motor is attached to a base plate of the disk drive. An actuator arm assembly is also mounted to the base plate. The cover encloses the spin motor, disk and actuator arm assembly. The drive also has at least one fastener that extends through the cover. The fastener(s) can be attached to the spin motor and/or the actuator arm assembly. The acoustic plate has an opening that is located adjacent to the fastener. The acoustic plug is located within the acoustic plate opening.

Abstract: A spindle motor assembly for a hard disk drive which has a fluid filled tube that dynamically balances the spindle motor. The assembly may include a hub which is rotated by an internal motor. A plurality of disks may be coupled to the hub and separated by a number of spacers. In one embodiment, the fluid filled tube is attached to the hub. In another embodiment, the fluid filled tube is attached to the spacer. The fluid within the tube is allowed to move during rotation of the hub. Movement of the fluid may dynamically balance the spindle motor.