Dell OptiPlex Gn+ User manual

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Information in this manual is subject to change without notice.
1997 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, the DELLlogo, and OptiPlex are registered trademarks of Dell Computer Corporation; Inteland Pentium are registered trademarks
and MMX is a trademark of Intel Corporation; Microsoft, MS-DOS, and Windows are registered trademarks of Microsoft Corporation; IBM is a registered trademark
of International 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.
October 1997 P/N 56023 Rev. A01

v
Contents
Chapter 1
System Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
System Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Advanced Expansion Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
Low-Profile Computer’s Expansion-Card Slots. . . . . . . . . . . . . . . . . 1-8
Midsize Computer’s Expansion-Card Slots . . . . . . . . . . . . . . . . . . . . 1-8
Mini Tower Computer’s Expansion-Card Slots . . . . . . . . . . . . . . . . . 1-9
Hard-Disk Drive Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
Low-Profile Computers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
Midsize Computers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
Mini Tower Computers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
Enhanced Dual-Interface EIDE Subsystem . . . . . . . . . . . . . . . . . . . . . . 1-11
Built-In Video Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
Optional NIC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
Floor Stand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
Computer Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
Computer Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
Pin Assignments for the DC Power Connectors. . . . . . . . . . . . . . . . 1-14
DC Power Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15
System Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-20
Main Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21
System Board Jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21
Interrupt Assignments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-23
DMA Channel Assignments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-24
Technical Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-25

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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Running the Dell Diagnostics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Getting Help. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
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 on the
Low-Profile Chassis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Recommended Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Precautionary Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Floor Stand. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
Computer Cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Eject, Power, and Reset Buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
Front-Panel Inserts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8
Drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
3.5-Inch Diskette Drive Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10
5.25-Inch Drive Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11
Hard-Disk Drive Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12
System Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13
System Board Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
Expansion Cards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
Expansion-Card Cage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
Expansion Card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16
Riser Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
DIMMs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Microprocessor/Heat Sink Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19
System Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21
System Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-22

vii
Chapter 5
Removing and Replacing Parts
on the Midsize Chassis. . . . . . . . . . . . . . . . . . . . . . . . . . 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8
Drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9
3.5-Inch Drive Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10
5.25-Inch Drive Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11
Hard-Disk Drive Bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12
Hard-Disk Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13
System Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14
System Board Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15
Expansion Cards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16
Expansion-Card Cage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16
Expansion Card. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17
Riser Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18
DIMMs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19
Microprocessor/Heat Sink Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20
System Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
System Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23
Chapter 6
Removing and Replacing Parts
on the Mini Tower Chassis . . . . . . . . . . . . . . . . . . . . . . . 6-1
Recommended Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Precautionary Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
Computer Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3
Front Bezel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
Eject, Power, and Reset Buttons. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
Front-Panel Inserts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8

viii
Drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-9
3.5-Inch Drive Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10
5.25-Inch Drive Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11
Hard-Disk Drive Bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13
Hard-Disk Drive. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-14
System Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-15
System Board Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-16
Expansion Cards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-17
Expansion-Card Cage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-17
Expansion Card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-18
Riser Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-19
DIMMs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-20
Microprocessor/Heat Sink Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . 6-21
System Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-23
System Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-24
Appendix A
System Setup Program . . . . . . . . . . . . . . . . . . . . . . . . . .A-1
System Setup Screens. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-2
Index
Figures
Figure 1-1. Computer Orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Figure 1-2. Front-Panel Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
Figure 1-3. Internal View of the Low-Profile Computer. . . . . . . . . . . . . 1-5
Figure 1-4. Internal View of the Midsize Computer . . . . . . . . . . . . . . . . 1-6
Figure 1-5. Internal View of the Mini Tower Computer . . . . . . . . . . . . . 1-7
Figure 1-6. Riser Board for the Low-Profile Computers. . . . . . . . . . . . . 1-8
Figure 1-7. EM Riser Board for the Low-Profile Computers . . . . . . . . . 1-8
Figure 1-8. Riser Board for the Midsize Computers . . . . . . . . . . . . . . . . 1-9
Figure 1-9. EM Riser Board for the Midsize Computers. . . . . . . . . . . . . 1-9
Figure 1-10. Riser Board for the Mini Tower Computers . . . . . . . . . . . . 1-10
Figure 1-11. EM Riser Board for the Mini Tower Computers . . . . . . . . 1-10
Figure 1-12. NIC Connector on I/O Panel. . . . . . . . . . . . . . . . . . . . . . . . 1-12
Figure 1-13. DC Power Connector P1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
Figure 1-14. DC Power Connectors P2 (Midsize and Mini Tower),
P3, P4, P5, P6, and P9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14

ix
Figure 1-15. DC Power Connectors P2 (Low-Profile) and P7. . . . . . . . . 1-15
Figure 1-16. DC Power Cables for the Low-Profile Computers . . . . . . . 1-15
Figure 1-17. DC Power Distribution for the Low-Profile Computers . . . 1-16
Figure 1-18. DC Power Cables for the Midsize
and Mini Tower Computers. . . . . . . . . . . . . . . . . . . . . . . . . 1-17
Figure 1-19. DC Power Distribution for the Midsize Computers . . . . . . 1-18
Figure 1-20. DC Power Distribution for the Mini Tower Computers . . . 1-19
Figure 1-21. System Board Components . . . . . . . . . . . . . . . . . . . . . . . . . 1-20
Figure 1-22. System Board Jumpers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21
Figure 4-1. Optional Floor Stand Removal . . . . . . . . . . . . . . . . . . . . . . . 4-3
Figure 4-2. Computer Cover Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Figure 4-3. Padlock. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Figure 4-4. Eject, Power, and Reset Button Removal . . . . . . . . . . . . . . . 4-5
Figure 4-5. 5.25-Inch Front-Panel Insert Removal. . . . . . . . . . . . . . . . . . 4-6
Figure 4-6. 3.5-Inch Front-Panel Insert Removal. . . . . . . . . . . . . . . . . . . 4-7
Figure 4-7. Control Panel Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8
Figure 4-8. Drive Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
Figure 4-9. 3.5-Inch Diskette Drive Removal . . . . . . . . . . . . . . . . . . . . 4-10
Figure 4-10. 5.25-Inch Drive Assembly Removal . . . . . . . . . . . . . . . . . . 4-11
Figure 4-11. Hard-Disk Drive Assembly Removal . . . . . . . . . . . . . . . . . 4-12
Figure 4-12. System Power-Supply Removal . . . . . . . . . . . . . . . . . . . . . 4-13
Figure 4-13. System Board Components . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
Figure 4-14. Expansion-Card Cage Removal. . . . . . . . . . . . . . . . . . . . . . 4-15
Figure 4-15. Expansion-Card Removal . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16
Figure 4-16. Riser Board Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
Figure 4-17. DIMM Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Figure 4-18. DIMM Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Figure 4-19. Microprocessor Securing-Clip Removal . . . . . . . . . . . . . . . 4-19
Figure 4-20. Microprocessor Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20
Figure 4-21. System Battery Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21
Figure 4-22. System Board Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-22
Figure 5-1. Floor Stand Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
Figure 5-2. Computer Cover Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
Figure 5-3. Padlock. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
Figure 5-4. Eject, Power, and Reset Button Removal . . . . . . . . . . . . . . . 5-5
Figure 5-5. 5.25-Inch Front-Panel Insert Removal. . . . . . . . . . . . . . . . . . 5-6
Figure 5-6. 3.5-Inch Front-Panel Insert Removal. . . . . . . . . . . . . . . . . . . 5-7
Figure 5-7. Control Panel Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8
Figure 5-8. Drive Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9

x
Figure 5-9. 3.5-Inch Diskette Drive Removal . . . . . . . . . . . . . . . . . . . . 5-10
Figure 5-10. 5.25-Inch Drive Assembly Removal. . . . . . . . . . . . . . . . . . 5-11
Figure 5-11. 5.25-Inch Drive Removal . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11
Figure 5-12. Hard-Disk Drive Bracket Removal. . . . . . . . . . . . . . . . . . . 5-12
Figure 5-13. Hard-Disk Drive Removal. . . . . . . . . . . . . . . . . . . . . . . . . . 5-13
Figure 5-14. System Power-Supply Removal . . . . . . . . . . . . . . . . . . . . . 5-14
Figure 5-15. System Board Components. . . . . . . . . . . . . . . . . . . . . . . . . 5-15
Figure 5-16. Expansion-Card Cage Removal . . . . . . . . . . . . . . . . . . . . . 5-16
Figure 5-17. Expansion-Card Removal . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17
Figure 5-18. Riser Board Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18
Figure 5-19. DIMM Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19
Figure 5-20. DIMM Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19
Figure 5-21. Microprocessor Securing-Clip Removal. . . . . . . . . . . . . . . 5-20
Figure 5-22. Microprocessor Removal . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21
Figure 5-23. System Battery Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
Figure 5-24. System Board Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23
Figure 6-1. Computer Cover Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3
Figure 6-2. Padlock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3
Figure 6-3. Front-Bezel Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
Figure 6-4. Eject, Power, and Reset Button Removal . . . . . . . . . . . . . . . 6-5
Figure 6-5. 5.25-Inch Front-Panel Insert Removal . . . . . . . . . . . . . . . . . 6-6
Figure 6-6. 3.5-Inch Front-Panel Insert Removal . . . . . . . . . . . . . . . . . . 6-7
Figure 6-7. Control Panel Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Figure 6-8. Drive Hardware. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-9
Figure 6-9. 3.5-Inch Drive Assembly Removal. . . . . . . . . . . . . . . . . . . 6-10
Figure 6-10. 3.5-Inch Diskette Drive Removal . . . . . . . . . . . . . . . . . . . . 6-11
Figure 6-11. 5.25-Inch Drive Assembly Removal. . . . . . . . . . . . . . . . . . 6-11
Figure 6-12. 5.25-Inch Drive Removal . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12
Figure 6-13. Hard-Disk Drive Bracket Removal. . . . . . . . . . . . . . . . . . . 6-13
Figure 6-14. Hard-Disk Drive Removal. . . . . . . . . . . . . . . . . . . . . . . . . . 6-14
Figure 6-15. System Power-Supply Removal . . . . . . . . . . . . . . . . . . . . . 6-15
Figure 6-16. System Board Components. . . . . . . . . . . . . . . . . . . . . . . . . 6-16
Figure 6-17. Expansion-Card Cage Removal . . . . . . . . . . . . . . . . . . . . . 6-17
Figure 6-18. Expansion-Card Removal . . . . . . . . . . . . . . . . . . . . . . . . . . 6-18
Figure 6-19. Riser Board Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-19
Figure 6-20. DIMM Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-20
Figure 6-21. DIMM Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-20
Figure 6-22. Microprocessor Securing-Clip Removal. . . . . . . . . . . . . . . 6-21

xi
Figure 6-23. Microprocessor Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . 6-22
Figure 6-24. System Battery Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-23
Figure 6-25. System Board Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-24
Figure A-1. System Setup Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-2
Figure A-2. Device List Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-6
Tables
Table 1-1. DC Voltage Ranges. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
Table 1-2. System-Board Jumper Descriptions . . . . . . . . . . . . . . . . . . 1-22
Table 1-3. Interrupt Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-23
Table 1-4. DREQ Line Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . 1-24
Table 1-5. Technical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-25
Table 3-1. POST Beep Codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Table 3-2. System Error Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
Table A-1. System Setup Categories. . . . . . . . . . . . . . . . . . . . . . . . . . . .A-3

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-compatible PC troubleshooting techniques. In addition to information
provided in this manual and the Reference and Installation Guide that came
with the system, Dell provides the Diagnostics and Troubleshooting Guide
fortroubleshootingproceduresandinstructionsonusingtheDellDiagnostics
to test the computer system.
WARNING: A WARNING indicates the potential for bodily harm and
provides 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

System Overview 1-1
Chapter 1
System Overview
T
he Dell®OptiPlex®Gn and Gn+, and the Dell OptiPlex Gn and Gn+ with
Enhanced Manageability (EM), are high-speed, upgradable, expandable com-
puters. (The name Dell OptiPlex Gn and Gn+ will be used to refer to both
versions, unless otherwise indicated.) They are available in three sizes: a low-
profile desktop computer, a midsize desktop computer, and a mini tower
computer. Chapters 1 through 3 and Appendix A contain information that
applies to all models of the DellOptiPlex Gn and Gn+ computers. Chapters 4, 5,
and 6 are chassis-specific.
The Dell OptiPlex Gn and Gn+ computers use the Intel®Pentium® micro-
processor with MMX™technology. These Dell computers incorporate the
high-performance PCI local bus as well as the ISA expansion bus. These buses
are built into the system board, which also integrates the microprocessor, mem-
ory controller, hard-disk drive controller, video controller, and other elements of
the basic computer.
The microprocessor for the OptiPlex Gn and Gn+ computers is installed in a
type 7 ZIF socket, which allows the computer to be upgraded when faster
microprocessors become available.
The Pentium microprocessor contains a built-in clock multiplier circuit, which
increases the internal operating frequency to a multiple of the system clock fre-
quency, which is 66 MHz.
The microprocessors for each of these computers and their operating frequen-
cies are as follows:
•Dell OptiPlex Gn and Gn+ 166 computers — 166-MHz Pentium micropro-
cessor with MMX technology
•Dell OptiPlex Gn and Gn+ 200 computers — 200-MHz Pentium micropro-
cessor with MMX technology
•Dell OptiPlex Gn and Gn+ 233 computers — 233-MHz Pentium micropro-
cessor with MMX technology

1-2 Dell OptiPlex Gn and Gn+ Systems Service Manual
S
ystem Features
In addition to the standard features found in a traditional personal computer, the
Dell OptiPlex Gn and Gn+ computers include the following new and/or
advanced features:
•Advanced combination ISA and PCI expansion subsystem
•Plug and Play ISA expansion-card capability
•Enhanced dual-interface EIDE subsystem
•Integrated cache memory controller that supports 512 KB of external
pipelined-burst cache memory
•Main system memory consisting of 16 to 256 MB of high-speed EDO
DIMMs
•Built-in SVGA controller attached to the PCI bus with 2 MB of video
memory
•Optional integrated 10- or 100-Mbps Ethernet NIC
•Optional NIC adapter providing Wakeup On LAN capability (available only
on the EM)
•Integrated Universal Serial Bus (USB) controller with two USB-compliant
connectors
•Self-Monitoring Analysis Reporting Technology (SMART)-compliant hard-
disk drives and SMART support in the system BIOS, which provides
notification at system start-up if a hard-disk drive has become unreliable
•New quick-test feature in the Dell Diagnostics (for more information about
Quick Test, see “Running the Dell Diagnostics” in Chapter 2).
All of these features except the new quick-test feature and the SMART support
are briefly described in this chapter.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
right
side
left
side
front
back
left
side
front
right
side
low-profile computer
mini tower computer
frontback
top
bottom
midsize computer
back

1-4 Dell OptiPlex Gn and Gn+ Systems Service Manual
Figure 1-2. Front-Panel Features
diskette-drive
access indicator
reset button
hard-disk drive
access indicator
power button
power indicator
diskette-drive
access indicator
reset button
hard-disk drive
access indicator
power button
power indicator
midsize computer
low-profile computer
mi
ni
to
wer
co
mputer
power indicator
hard-disk drive
access indicator
power button
reset button
diskette-drive
access indicator
cover release button

System Overview 1-5
Figure 1-3. Internal View of the Low-Profile Computer
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.
serial port 1
connector
power supply
voltage
selection
switch
AC power
receptacle
3.5-inch diskette drive
expansion-card
cage
USB connectors (2)
keyboard connector
video connector
expansion-card slots (3)
hard-disk drive
optional system board
NIC connector (Gn+)
hard-disk drive
interface cable
diskette/tape drive
interface cable
parallel port
connector
mouse connector
serial port 2 connector
padlock ring
security cable slot
system board

1-6 Dell OptiPlex Gn and Gn+ Systems Service Manual
Figure 1-4. Internal View of the Midsize Computer
parallel port connector
power supply
voltage
selection switch
AC power
receptacle
serial port 1 connector
drive cage
diskette/tape drive interface cable hard-disk drive
bracket
hard-disk drive
interface cable
3.5-inch diskette drive
expansion-card cage
expansion-card slots (5)
video connector
padlock ring
security cable slot
system board
optional system board
NIC connector (Gn+)
USB connectors (2)
keyboard connector
mouse connector
serial port 2 connector

System Overview 1-7
Figure 1-5. Internal View of the Mini Tower Computer
Advanced Expansion Subsystem
The Dell OptiPlex Gn and Gn+ computers offer advanced expansion sub-
systems that can support a mixture of traditional ISA expansion cards (called
legacy cards), Plug and Play ISA expansion cards, and PCI expansion cards. The
operating system or the ISA Configuration Utility (ICU), included with the
computer, provides a means of avoiding resource conflicts that might arise from
such an arrangement.
NOTE: For systems running the Microsoft®Windows®95 operating system,
the functions provided by the ICU are handled by the Device Manager, which
can be accessed by double-clicking the System icon in the Control Panel.
Windows 95 documentation provides instructions on using the Device Manager
to manage resources and resolve conflicts.
After all legacy cards have been configured by the operating system or with the
ICU, the computer automatically 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.
power supply
security cable slot
AC power receptacle
parallel port connector
mouse connector
keyboard connector
serial port 1 connector
video connector
padlock ring
system board
expansion-card cage
riser board
hard-disk drive
bracket
internal drive bays
hard-disk drive
interface cable
voltage selection switch
serial port 2 connector
optional system board
NIC connector (Gn+)
USB connectors (2)

1-8 Dell OptiPlex Gn and Gn+ Systems Service Manual
Low-Profile Computer’s Expansion-Card Slots
The low-profile computers have 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 1-6). The low-profile computers have a passive riser board,
with no PCI-to-PCI bridge.
Figure 1-6. Riser Board for the Low-Profile Computers
If you have the EM version of the low-profile computer, the riser board for the
computer is different (see Figure 1-7). P1 is the network card connection on the
riser board. If the LED is on, the riser is receiving power, if it is off, the riser is
not receiving power.
Figure 1-7. EM Riser Board for the Low-Profile Computers
Midsize Computer’s Expansion-Card Slots
The midsize computers have five expansion-card slots and a passive riser board,
with no PCI-to-PCI bridge. The computer has three ISA expansion-card con-
nectors and three PCI expansion-card connectors. One PCI expansion-card
HDLED
connector
ISA2
connector
ISA1
connector
PCI2
connector
PCI1
connector
ISA2
connector
LED
PCI2
connector
PCI1
connector
HDLED
ISA1
connector
P1
connector