System Design; Design Overview - Compaq DESKPRO 2000 SERIES Maintenance & Service Manual

1.3 System Design

This section presents a design overview and functional descriptions of the key components of the
Compaq Deskpro 2000 Series of Personal Computers. All replaceable components are identified in
Chapter 3, and removal/replacement instructions are presented in Chapter 5.

1.3.1 Design Overview

The desktop models of the Compaq Deskpro 2000 Series of Personal Computers have a conventional
design that uses a pan-type chassis to house the system board, expansion cards, power supply, and mass
storage devices. The chassis is supplemented by a riser board attached to the riser brace. The riser board
provides a mounting location for the expansion cards.
All internal components are accessible when the hood, held in place by two thumbscrews, is removed.
The front bezel is mounted to the front of the chassis. Torx T-15 screws are used throughout the system
except for the power supply switch mounting bracket, which uses T-10 screws.
The system board is easily removed from the side of the chassis after the hood and riser board are
removed. Two mounting screws secure the riser board to the riser brace. Four mounting screws are used
on the Pentium and five screws on the Pentium Pro to secure the system board to the chassis. In
addition, the I/O bracket is mounted to the system board and is spared that way.
The riser board mounts perpendicular to the system board. Expansion boards are installed horizontally
into the riser board. A single screw attaches each expansion board to the rear panel of the chassis.
The power supply is mounted in the right rear corner of the chassis. The power supply is held in place
by five Torx screws, two mounted internally and three that are installed through the rear panel of the
chassis.
The minitower models' chassis is designed to house the system board, riser board, option cards, power
supply, and mass storage devices. The use of a riser brace to hold the riser board, and any expansion
boards installed, allows for easy access to the system board. The power supply is mounted in the top of
the unit.
All internal components are immediately accessible when the side panel, held in place with three
thumbscrews, is removed. The front bezel is a separate assembly that mounts to the front of the chassis.
The tray-mounted system board is easily removed by taking off the side panel, removing the riser brace,
and then pulling the tray assembly from the chassis. The system board is spared installed in the tray.
Detailed descriptions of the system components are presented in the sections that follow.
1-6 Product Description