Dell OptiPlex Gs User manual

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Information in this document is subject to change without notice.
1996 Dell Computer Corporation. All rights reserved.
Reproduction in any manner whatsoever without the written permission of Dell Computer Corporation is strictly forbidden.
Trademarks used in this text: Dell,theDELL logo,andOptiPlex are registered trademarks of Dell Computer Corporation; Intel and Pentium are registered trademarks
ofIntelCorporation; Microsoft,Windows,WindowsNT,andMS-DOSareregisteredtrademarksofMicrosoftCorporation;IBMisaregisteredtrademarkofInternational
Business Machines Corporation; 3Com is a registered trademark of 3Com Corporation.
Other trademarks and trade names may be used in this document to refer to either the entities claiming the marks and names or their products. Dell Computer
Corporation disclaims any proprietary interest in trademarks and trade names other than its own.
November 1996 P/N 93817

v
Contents
Chapter 1
System Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
System Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Advanced Expansion Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Low-Profile Computer’s Expansion-Card Slots. . . . . . . . . . . . . . . . . 1-6
Midsize Computer’s Expansion-Card Slots . . . . . . . . . . . . . . . . . . . . 1-6
Hard-Disk Drive Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
Low-Profile Computer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
Midsize Computer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
Enhanced Dual-Interface EIDE Subsystem . . . . . . . . . . . . . . . . . . . . . . . 1-7
Built-In Video Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
Built-In NIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
Floor Stand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
Computer Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
System Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Pin Assignments for the DC Power Connectors. . . . . . . . . . . . . . . . 1-10
DC Power Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
System Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16
Main Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16
System Board Jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17
DMA Channel Assignments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-18
Interrupt Assignments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-19
Technical Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-20

vi
Chapter 2
Basic Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Initial User Contact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
External Visual Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Observing the Boot Routine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Internal Visual Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Eliminating Resource Conflicts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Running the Diskette-Based Diagnostics. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Getting Help. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Chapter 3
Beep Codes and Error Messages . . . . . . . . . . . . . . . . . . 3-1
POST Beep Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
System Error Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
Chapter 4
Removing and Replacing Parts in the
Low-Profile System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Recommended Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Precautionary Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Computer Cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
Eject, Power, and Reset Buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Front-Panel Inserts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
Drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7
3.5-Inch Diskette Drive Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8
5.25-Inch Drive Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
Hard-Disk Drive Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10
System Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11
System Board Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12
Expansion Cards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13
Expansion-Card Cage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13
Expansion Card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
Riser Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15

vii
SIMMs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16
Video Memory Chips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
Microprocessor/Heat Sink Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
System Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20
System Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21
Chapter 5
Removing and Replacing Parts in the
Midsize System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
Recommended Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
Precautionary Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
Floor Stand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
Computer Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
Eject, Power, and Reset Buttons. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
Front-Panel Inserts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
Drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8
Externally Accessible Drive Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . 5-9
Hard-Disk Drive Bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11
Hard-Disk Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12
System Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13
System Board Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14
Expansion Cards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15
Expansion-Card Cage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15
Expansion Card. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16
Riser Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17
SIMMs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18
Video Memory Chip. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19
Microprocessor/Heat Sink Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20
System Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
System Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23
Appendix A
System Setup Program. . . . . . . . . . . . . . . . . . . . . . . . . . A-1
System Setup Screens. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-2
Index

viii
Figures
Figure 1-1. Computer Orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Figure 1-2. Front-Panel Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Figure 1-3. Internal View of the Low-Profile Computer . . . . . . . . . . . . . . 1-4
Figure 1-4. Internal View of the Midsize Computer . . . . . . . . . . . . . . . . . 1-5
Figure 1-5. Riser Board for the Low-Profile Computer. . . . . . . . . . . . . . . 1-6
Figure 1-6. Riser Board for the Midsize Computer . . . . . . . . . . . . . . . . . . 1-6
Figure 1-7. DC Power Connector P1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
Figure 1-8. DC Power Connectors P2 (Midsize Computer),
P3, P4, P5, and P6 (Midsize Computer) . . . . . . . . . . . . . . . . 1-10
Figure 1-9. DC Power Connectors P2 (Low-Profile Computer) and
P7 (Midsize Computer) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
Figure 1-10. DC Power Cables for the Low-Profile Computer . . . . . . . . . 1-12
Figure 1-11. DC Power Distribution for the Low-Profile Computer. . . . . 1-13
Figure 1-12. DC Power Cables for the Midsize Computer . . . . . . . . . . . . 1-14
Figure 1-13. DC Power Distribution for the Midsize Computer . . . . . . . . 1-15
Figure 1-14. System Board Components . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16
Figure 1-15. System Board Jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17
Figure 4-1. Computer Cover Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
Figure 4-2. Eject-, Power, and Reset-Button Removal . . . . . . . . . . . . . . . 4-4
Figure 4-3. Front-Panel Insert Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
Figure 4-4. Control Panel Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
Figure 4-5. Drive Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7
Figure 4-6. 3.5-Inch Diskette-Drive Assembly Removal . . . . . . . . . . . . . 4-8
Figure 4-7. 5.25-Inch Drive Assembly Removal. . . . . . . . . . . . . . . . . . . . 4-9
Figure 4-8. Hard-Disk Drive Assembly Removal . . . . . . . . . . . . . . . . . . 4-10
Figure 4-9. System Power-Supply Removal . . . . . . . . . . . . . . . . . . . . . . 4-11
Figure 4-10. System Board Components . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12
Figure 4-11. Expansion-Card Cage Removal . . . . . . . . . . . . . . . . . . . . . . 4-13
Figure 4-12. Expansion-Card Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
Figure 4-13. Riser Board Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
Figure 4-14. SIMM Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16
Figure 4-15. SIMM Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16
Figure 4-16. Video-Memory Chip Removal . . . . . . . . . . . . . . . . . . . . . . . 4-17
Figure 4-17. Microprocessor Securing-Clip Removal. . . . . . . . . . . . . . . . 4-18
Figure 4-18. Microprocessor and Heat Sink Assembly . . . . . . . . . . . . . . . 4-19
Figure 4-19. System Battery Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20
Figure 4-20. System Board Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21

ix
Figure 5-1. Floor Stand Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
Figure 5-2. Computer Cover Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
Figure 5-3. Eject-, Power, and Reset-Button Removal. . . . . . . . . . . . . . . . 5-5
Figure 5-4. Front-Panel Insert Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
Figure 5-5. Control Panel Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
Figure 5-6. Drive Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8
Figure 5-7. 3.5-Inch Diskette-Drive Assembly Removal. . . . . . . . . . . . . . 5-9
Figure 5-8. 5.25-Inch Drive Assembly Removal . . . . . . . . . . . . . . . . . . . 5-10
Figure 5-9. 5.25-Inch Drive Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10
Figure 5-10. Hard-Disk Drive Bracket Removal . . . . . . . . . . . . . . . . . . . . 5-11
Figure 5-11. Hard-Disk Drive Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12
Figure 5-12. System Power-Supply Removal. . . . . . . . . . . . . . . . . . . . . . . 5-13
Figure 5-13. System Board Components . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14
Figure 5-14. Expansion-Card Cage Removal. . . . . . . . . . . . . . . . . . . . . . . 5-15
Figure 5-15. Expansion-Card Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16
Figure 5-16. Riser Board Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17
Figure 5-17. SIMM Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18
Figure 5-18. SIMM Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18
Figure 5-19. Video-Memory Chip Removal. . . . . . . . . . . . . . . . . . . . . . . . 5-19
Figure 5-20. Microprocessor Securing-Clip Removal . . . . . . . . . . . . . . . . 5-20
Figure 5-21. Microprocessor and Heat Sink Assembly . . . . . . . . . . . . . . . 5-21
Figure 5-22. System Battery Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
Figure 5-23. System Board Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23
Figure A-1. System Setup Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-2
Tables
Table 1-1. DC Voltage Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Table 1-2. System-Board Jumper Descriptions. . . . . . . . . . . . . . . . . . . . 1-18
Table 1-3. DREQ Line Assignments. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-18
Table 1-4. Interrupt Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-19
Table 1-5. Technical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-20
Table 3-1. POST Beep Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Table 3-2. System Error Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
Table A-1. System Setup Categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-3

x

xi

R
ead This First
W
arnings, Cautions, and Notes
Throughout this manual, there may be blocks of text printed in bold type or in
italic type. These blocks are warnings, cautions, and notes, and they are used as
follows:
NOTE: A NOTE provides helpful information about using the computer system.
A prerequisite for using this manual to service Dell computer systems is a
basic knowledge of IBM®-compatible PCs and prior training in IBM-com-
patible PC troubleshooting techniques. In addition to information provided
in thismanual and theUser’s Guide that came with the system, Dell provides
the Diagnostics and Troubleshooting Guide for troubleshooting procedures
and instructions on using the Dell diagnostics to test the computer system.
WARNING: A WARNING indicates the potential for bodily harm and pro-
vides instructions for how to avoid the problem.
CAUTION: A CAUTION indicates either potential damage to hardware or
loss of data and provides instructions for how to avoid the problem.
xii

xiii

xiv

System Overview 1-1
Chapter 1
System Overview
T
he Dell®OptiPlex®Gs and Gs+ systems are high-speed desktop computers.
The Dell OptiPlex Gs and Gs+ systems are available in two sizes: a low-profile
desktop computer and a midsize desktop computer. Chapters 1 through 3 and
Appendix A contain information that applies to all models of the Dell OptiPlex
Gs and Gs+ systems. Chapters 4 and 5 provide chassis-specific parts removal
and replacement procedures.
The Dell OptiPlex Gs and Gs+ systems use the Intel® Pentium®family of
microprocessors. These Dell computers incorporate the high-performance PCI
expansion bus as well as the ISA expansion bus. These buses are built into the
system board, which also integrates the microprocessor, memory controller,
hard-disk controller, video controller, and other elements of the basic computer.
The microprocessor for the OptiPlex Gs and GS+ systems is installed in a ZIF
socket, which allows the computer to be upgraded when faster microprocessors
become available. Contact Dell for information about Dell-supported micro-
processor upgrades.
The Pentium microprocessor contains a built-in clock multiplier circuit, which
increases the internal operating frequency to a multiple of the system clock
frequency.
The microprocessor operating frequencies for each of these computers are as
follows:
•Dell OptiPlex Gs and Gs+ 133 systems — 133 MHz derived from a system
clock frequency of 66 MHz
•Dell OptiPlex Gs and Gs+ 166 systems — 166 MHz derived from a system
clock frequency of 66 MHz
•Dell OptiPlex Gs and Gs+ 200 systems — 200 MHz derived from a system
clock frequency of 66 MHz

1-2 Dell OptiPlex Gs and Gs+ Systems Service Manual
S
ystem Features
In addition to the features found in a standard desktop computer, the Dell Opti-
Plex Gs and Gs+ systems include the following new and/or advanced features:
•ISA and PCI expansion subsystem
•Plug and Play ISA expansion-card capability
•Enhanced dual-interface EIDE subsystem
•Integrated cache of 256 KB of SRAM
•Main system memory consisting of 8 to 128 MB of high-speed EDO
SIMMs
•Built-in SVGA controller attached to the PCI bus
•On the Gs+ models, integrated Ethernet NIC
•Mini tower capability by attaching a floor stand
•Self-monitoring analysis reporting technology (SMART)-compliant hard-
disk drives and SMART support in the system BIOS, which generates an
error message at system start-up if a hard-disk drive has become unreliable
•Quick-test feature in the diskette-based diagnostics (see“Runningthe
Diskette-Based Diagnostics” in Chapter 2)
For a complete list of system features, see “Technical Specifications” found
later in this chapter.
When following the text in this manual, assume that the location or direction
relative to the computer is as shown in Figure 1-1.

System Overview 1-3
Figure 1-1. Computer Orientation
Figure 1-2. Front-Panel Features
CAUTION: To avoid possible data or file structure corruptions, the
front-panel reset button should be used only when the computer cannot
be rebooted by pressing <CTRL><ALT><DEL>. Before you use the reset
button to initiate a hardware reset, close any open application programs
and files if possible.
right
side
left
side
front
back
left
side
front
right
side
back
Low-Profile Computer Midsize Computer
reset button
hard-disk drive
access indicator
power button
power indicator
diskette-drive
access indicator

1-4 Dell OptiPlex Gs and Gs+ Systems Service Manual
Figure 1-3. Internal View of the Low-Profile Computer
power supply
voltage selection
switch
AC power
receptacle
3.5-inch diskette drive
expansion-card
cage
parallel port
connector
serial port 1
connector
serial port 2 connector
keyboard connector
video connector
expansion-card
slots (3)
hard-disk drive
NIC connector
hard-disk drive
interface cable
diskette/tape drive
interface cable
mouse connector
DC power cable

System Overview 1-5
Figure 1-4. Internal View of the Midsize Computer
Advanced Expansion Subsystem
The Gs and Gs+ systems offers advanced expansion subsystems that can sup-
port a mixture of traditional ISA expansion cards (called legacy cards), Plug and
Play ISA expansion cards, and PCI expansion cards. The ISA Configuration Utility
(ICU) included with the computer provides a means of avoiding resource conflicts
that might arise from such an arrangement.
After all legacy cards have been configured with the ICU, the computer auto-
matically assigns any required memory space, IRQ lines, and DMA channels to
any installed Plug and Play ISA expansion cards and PCI expansion cards the
next time the computer is rebooted. Chapter 3, “Using the ISA Configuration
Utility,” in the Reference and Installation Guide describes the ICU and provides
instructions for using it to configure the computer.
NOTES: If the Microsoft®Windows NT®operating system is being used, set
any Plug and Play expansion cards to legacy mode using the card manufac-
turer’s configuration utility and enter the card’s resources with this utility. Then
run the ICU and add the card to the system’s configuration.
The ICU is not required for the Microsoft Windows®95 operating system
because the same functions are provided by the Device Manager.
parallel port connector
power supply
voltage
selection
switch
AC power
receptacle
serial port 1 connector
serial port 2 connector
keyboard connector
mouse connector
NIC connector
DC power cable
diskette/tape drive
interface cable hard-disk drive
bays (2)
3.5-inch diskette drive
expansion-card
cage
expansion-card slots (5)
video connector

1-6 Dell OptiPlex Gs and Gs+ Systems Service Manual
Low-Profile Computer’s Expansion-Card Slots
The low-profile computer has three expansion-card slots. The riser board has
two ISA expansion-card connectors and two PCI expansion-card connectors.
One PCI expansion-card connector and one ISA expansion-card connector
share a single expansion-card slot, resulting in a total of three expansion-card
slots (see Figure 1-5).
Figure 1-5. Riser Board for the Low-Profile Computer
Midsize Computer’s Expansion-Card Slots
The midsize computer has five expansion-card slots. The riser board has three
ISA expansion-card connectors and three PCI expansion-card connectors. One
PCI expansion-card connector and the one ISA expansion-card connector share
a single expansion-card slot, resulting in a total of five expansion-card slots (see
Figure 1-6).
Figure 1-6. Riser Board for the Midsize Computer
H
D
LED
connector
ISA2
connector
PCI2
connector
PCI1
connector
ISA1
connector
H
D
LED
connector
ISA3
connector
ISA2
connector
ISA1
connector
PCI3
connector
PCI2
connector
PCI1
connector

System Overview 1-7
Hard-Disk Drive Options
Low-Profile Computer
The hard-disk drive assembly (consisting of the hard-disk drive and the hard-
disk drive bracket) is located inside the left front area of the chassis and is
attached to the bottom of the chassis. One EIDE or SCSI 1-inch-high hard-disk
drive can be mounted on the hard-disk drive mounting bracket.
Midsize Computer
The hard-disk drive bracket is located next to the externally accessible drive
bays at the front of the computer. The hard-disk drive bracket can contain either
one or two 1-inch-high EIDE or SCSI hard-disk drives, or it can hold one
1-inch-high EIDE or SCSI hard-disk drive and one 1.6-inch-high EIDE or SCSI
hard-disk drive.
Enhanced Dual-Interface EIDE Subsystem
The EIDE subsystem provides two mode-4, DMA bus-mastered EIDE inter-
faces, each of which can support up to two EIDE devices. The EIDE controller
attaches to the high-speed PCI local bus.
The primary EIDE interface (IDE1) provides support for up to two high-
performance EIDE devices, such as hard-disk drives. The computer’s boot drive
should be connected to the primary EIDE interface.
The secondary EIDE interface (IDE2) provides support for up to two additional
EIDE devices, typically EIDE tape drives or CD-ROM drives.
NOTE: The externally accessible drive bays at the front of the computer are
normally used for diskette drives, CD-ROM drives, and/or tape drives. Hard-
disk drives should be installed in the internal hard-disk drive bracket described
in “Hard-Disk Drive Options” found earlier in this chapter. For detailed infor-
mation about the data storage subsystem, see Chapter 7, “Installing Drives,” in
the Reference and Installation Guide.
Built-In Video Controller
The video subsystem consists of a high-speed, high-resolution video controller
built into the system board. Because the video controller connects to the PCI bus
rather than to the ISA bus, communication between the video subsystem and the
microprocessor is much faster. The PCI bus operates at a frequency of 33 MHz as
compared to the 8.25-MHz operating frequency of the ISA bus.
The built-in video controller includes 1 MB of video memory built into the sys-
tem board, with sockets for an additional 1 MB of video memory.

1-8 Dell OptiPlex Gs and Gs+ Systems Service Manual
Built-In NIC
The Gs+ systems have a built-in integrated 3Com®3C915 Ethernet NIC sub-
system. The NIC subsystem connects to an RJ45 connector on the back panel of
the computer.
Chapter 4, “Using the Network Interface Controller,” in the Reference and
Installation Guide provides instructions for connecting the computer to, and
configuring it for use on, an Ethernet network.
Floor Stand
The computers can be used as either a desktop (horizontal) or a mini tower (ver-
tical) computer. The floor stand is optional on the low-profile computers and is
included with the midsize computers. The floor stand can be attached to the left
side of the computer to orient it as a mini tower computer.