Chapter 1: General Information; Introduction; General Description - HP 9130K Service Manual

Chapter
1
General Information
Introduction
This service manual provides detailed information for servicing the 9130K disc drive.
Service Philosophy
The 9130K Flexible Disc Drive is comprised of three serviceable areas: the mechanical drive
assembly, the drive electronics assembly and the servo electronics assembly. All assemblies
are serviced on the exchange program with the exception of some parts on the mechanical
assembly. The field replaceable parts are outlined in the maintenance and assembly access
sections.
General Description
The
HP
9130K rnini double sided flexible disc drive is a semi-random access mass storage
system employing a flexible magnetic medium. It consists of a mini disc drive, a servo
electronics circuit board and a drive electronics circuit board.
Each drive module contains all the mechanical parts necessary for physically handling the
disc. These include the drive spindle and motor, 2 heads each having read/write and erase
capability, write protect sensor, track 0 sensor, index sensor, and activity LED on the front
panel. Each drive module also contains a servo control board which controls the DC drive
motor speed and a drive electronics board which interprets and generate control signals,
controls movement of the read/write head to the correct position, and also reads and writes
data.
The flexible magnetic medium used in the 9130K is called a flexible disc. The flexible disc
measures 133.4 mm (5.25 inches) on a side and has a 3.8 cm (1.5 inch) hole for alignment
on the disc drive spindle. The disc is enclosed in a protective polyvinylchloride (PVC) jacket
with a slot for access to the recording surface. Both sides of the flexible disc are used for data
storage.
The recording head in the drive module is positioned by a mechanism driven by a stepper
motor and taut metal band. The head positioning mechanism operates in an open loop
configuration, that is, there is no feedback to the drive electronics board to determine the
actual position of the head.
The heads are mechanically coupled to the door mechanism so that closing of the door
causes the heads to make contact with the media.