Dell Dimension XPS R Series User manual

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____________________
Information in this document is subject to change without notice.
© 1998 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 DELL logo, and Dell Dimension are registered trademarks of Dell Computer Corporation; Intel and Pentium are
registered trademarks and
MMX is a trademark of Intel Corporation; Microsoft , Windows , and MS-DOS are registered trademarks of Microsoft
Corporation;
IBM is a registered trademark of International Business Machines Corporation; VESA is a registered trademark of Video Electronics
Standards Association.
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.
March 1998 P/N 24920

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&KDSWHU 6\VWHP2YHUYLHZ  
System Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Advanced Expansion Subsystem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
EIDE Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Hard-Disk Drive Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Computer Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
DC Power Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
DC Power Connector Pin Assignments. . . . . . . . . . . . . . . . . . . . . 1-10
System Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
Main Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
System Board Jumper. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
Interrupt Assignments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16
DMA Channel Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17
Technical Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-18
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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 Dell Diagnostics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Getting Help. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
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POST Beep Codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
System Messages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
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Recommended Tools. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Precautionary Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

vi
Computer Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Bezel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
Drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
Removing and Replacing a Front-Panel Insert. . . . . . . . . . . . . . . . . . . . 4-3
Removing a 3.5-Inch Insert . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Drive Cage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
5.25-Inch Drive. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
Upper 3.5-Inch Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8
Lower 3.5-Inch Drive (Mini Tower Computer Only). . . . . . . . . . . . . . . . 4-9
3.5-Inch Diskette Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10
Primary Hard-Disk Drive. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11
Secondary Hard-Disk Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12
Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
Chassis Cooling Fan Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
Card Guide Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16
Control Panel Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
System Board Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Expansion Cards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19
DIMMs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19
SEC Cartridge and Heat Sink Assembly . . . . . . . . . . . . . . . . . . . . . . . 4-21
Replacing the Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-23
System Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24
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System Setup Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
Main Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
Advanced Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
Peripheral Configuration Submenu . . . . . . . . . . . . . . . . . . . . . . . . . A-4
IDE Configuration Submenu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5
Primary IDE Master Submenu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-7
Diskette Options Submenu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-8
DMI Event Logging Submenu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-9
Video Configuration Submenu. . . . . . . . . . . . . . . . . . . . . . . . . . . . A-10
Resource Configuration Submenu. . . . . . . . . . . . . . . . . . . . . . . . . A-11
Security Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-12
Power Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-13
Boot Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-14
Hard Drive Submenu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-16
Removable Devices Submenu. . . . . . . . . . . . . . . . . . . . . . . . . . . . A-17
Exit Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-17
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vii
)LJXUHV Figure 1-1. Computer Orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Figure 1-2. Internal View of Desktop Computer . . . . . . . . . . . . . . . . . . . 1-4
Figure 1-3. Internal View of Mini Tower Computer. . . . . . . . . . . . . . . . . 1-5
Figure 1-4. Back-Panel Features (Typical) . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Figure 1-5. DC Power Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
Figure 1-6. DC Power Distribution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Figure 1-7. DC Power Connector P1. . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
Figure 1-8. DC Power Connectors P2, P3, P4, P5, and P6 . . . . . . . . . . 1-11
Figure 1-9. DC Power Connector P7. . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
Figure 1-10. System Board Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
Figure 1-11. System Board Jumper (J8A1) . . . . . . . . . . . . . . . . . . . . . . . 1-14
Figure 4-1. Computer Cover Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Figure 4-2. Bezel Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
Figure 4-3. 3.5-Inch Insert Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Figure 4-4. Drive Cage Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
Figure 4-5. 5.25-Inch Insert Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
Figure 4-6. 5.25-Inch Drive Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7
Figure 4-7. Upper 3.5-Inch Drive Removal . . . . . . . . . . . . . . . . . . . . . . . 4-8
Figure 4-8. Lower 3.5-Inch Drive Removal
(Mini Tower Computer Only). . . . . . . . . . . . . . . . . . . . . . . . . 4-9
Figure 4-9. 3.5-Inch Diskette Drive Removal. . . . . . . . . . . . . . . . . . . . . 4-10
Figure 4-10. Primary Hard-Disk Drive Removal. . . . . . . . . . . . . . . . . . . . 4-11
Figure 4-11. Secondary Hard-Disk Drive Assembly Removal . . . . . . . . . 4-12
Figure 4-12. Secondary Hard-Disk Drive Removal. . . . . . . . . . . . . . . . . . 4-13
Figure 4-13. Power Supply Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
Figure 4-14. Chassis Cooling Fan Assembly Removal . . . . . . . . . . . . . . 4-15
Figure 4-15. Card-Guide Assembly Removal. . . . . . . . . . . . . . . . . . . . . . 4-16
Figure 4-16. Control-Panel Board Removal . . . . . . . . . . . . . . . . . . . . . . . 4-17
Figure 4-17. System Board Components . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Figure 4-18. Expansion Card Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19
Figure 4-19. DIMM Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19
Figure 4-20. DIMM Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20
Figure 4-21. SEC Cartridge and Heat Sink Removal . . . . . . . . . . . . . . . . 4-21
Figure 4-22. Battery Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-23
Figure 4-23. System Board Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24
Figure 4-24. Guide-Bracket Assembly Removal . . . . . . . . . . . . . . . . . . . 4-25
Figure 4-25. Mounting Screw and Bracket . . . . . . . . . . . . . . . . . . . . . . . 4-26
Figure 4-26. System Board Mountings . . . . . . . . . . . . . . . . . . . . . . . . . . 4-26
Figure 4-27. Bracket Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-27
Figure A-1. Main Screen Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
Figure A-2. Advanced Screen Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
Figure A-3. Peripheral Configuration Submenu . . . . . . . . . . . . . . . . . . . . A-4

viii
Figure A-4. IDE Configuration Submenu . . . . . . . . . . . . . . . . . . . . . . . . . A-5
Figure A-5. Primary IDE Master Submenu . . . . . . . . . . . . . . . . . . . . . . . A-7
Figure A-6. Diskette Options Submenu. . . . . . . . . . . . . . . . . . . . . . . . . . A-8
Figure A-7. DMI Event Logging Submenu. . . . . . . . . . . . . . . . . . . . . . . . A-9
Figure A-8. Video Configuration Submenu . . . . . . . . . . . . . . . . . . . . . . A-10
Figure A-9. Resource Configuration Submenu . . . . . . . . . . . . . . . . . . . A-11
Figure A-10. Security Screen Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-12
Figure A-11. Power Screen Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-13
Figure A-12. Boot Screen Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-14
Figure A-13. Hard Drive Submenu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-16
Figure A-14. Removable Devices Submenu . . . . . . . . . . . . . . . . . . . . . . A-17
Figure A-15. Exit Screen Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-17
7DEOHV Table 1-1. DC Voltage Ranges. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
Table 1-2. System Board Jumper Descriptions . . . . . . . . . . . . . . . . . . 1-15
Table 1-3. Interrupt Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16
Table 1-4. DMA Channel Assignments . . . . . . . . . . . . . . . . . . . . . . . . 1-17
Table 1-5. Technical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-18
Table 3-1. POST Beep Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Table 3-2. System Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Table A-1. Main Screen Menu Options . . . . . . . . . . . . . . . . . . . . . . . . . A-2
Table A-2. Advanced Screen Menu Options . . . . . . . . . . . . . . . . . . . . . A-3
Table A-3. Peripheral Configuration Submenu Options . . . . . . . . . . . . . A-4
Table A-4. IDE Configuration Submenu Options . . . . . . . . . . . . . . . . . . A-6
Table A-5. Primary IDE Master Submenu Options. . . . . . . . . . . . . . . . . A-7
Table A-6. Diskette Options Submenu Options. . . . . . . . . . . . . . . . . . . A-8
Table A-7. DMI Event Logging Submenu Options. . . . . . . . . . . . . . . . . A-9
Table A-8. Video Configuration Submenu Options. . . . . . . . . . . . . . . . A-10
Table A-9. Resource Configuration Submenu Options. . . . . . . . . . . . . A-11
Table A-10. Security Screen Menu Options. . . . . . . . . . . . . . . . . . . . . . A-12
Table A-11. Power Screen Menu Options . . . . . . . . . . . . . . . . . . . . . . . A-13
Table A-12. Boot Screen Menu Options . . . . . . . . . . . . . . . . . . . . . . . . A-14
Table A-13. Hard Drive Submenu Options . . . . . . . . . . . . . . . . . . . . . . . A-16
Table A-14. Removable Devices Submenu Options . . . . . . . . . . . . . . . A-17
Table A-15. Exit Screen Menu Options . . . . . . . . . . . . . . . . . . . . . . . . . A-18

ix

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A prerequisite for using thismanual 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
User’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.
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as follows:
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NOTE: A NOTE provides helpful information about using the computer system.

System Overview 1-1
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The Dell Dimension®XPS R
xxx
systems are high-speed computer systems
that use an Intel®Pentium®II microprocessor with MMX™technology. These
Dell®systems combine Peripheral Component Interconnect (PCI) design with
an accelerated graphics port (AGP) and Industry Standard Architecture (ISA)
design that allows a wide range of initial configurations and upgrade
possibilities.
The Dell Dimension XPS R
xxx
systems are available in either a desktop or a
mini tower configuration. Both configurations use the same system board and
base chassis. The only difference, other than physical mounting, is the number
of externally accessible 3.5-inch drive bays.
The front of the computer has two 5.25-inch drive bays and one 3.5-inch
diskette-drive bay. In addition, the mini tower systems have two 3.5-inch drive
bays and the desktop system has one 3.5-inch drive bay. The 5.25- and 3.5-inch
drive bays can hold diskette drives, tape drives, or CD-ROM drives.
The Pentium II microprocessor contains a built-in clock multiplier circuit that
increases the internal operating frequency to a multiple of the system clock
frequency, which is 100 MHz.
The microprocessors for each of these computers and their operating frequen-
cies are as follows:
Dell Dimension XPS R350 systems — 350-MHz Pentium II microprocessor
with MMX technology
Dell Dimension XPS R400 systems — 400-MHz Pentium II microprocessor
with MMX technology
A single-edge contact (SEC) cartridge connected to the system board contains
the system’s microprocessor and cache circuitry.
Main memory consists of up to three DIMMs. The base configuration for main
memory is one 64-MB DIMM. Main memory can be expanded up to 384 MB
by using 32-, 64-, or 128-MB DIMMs.

1-2 Dell Dimension XPS R xxx Systems Service Manual
6\VWHP)HDWXUHV
In addition to the standard features found in a traditional personal computer,
the Dell Dimension XPS R
xxx systems include the following:
An Intel Pentium II microprocessor with MMX technology, that is specifi-
cally designed to handle complex multimedia and communications
software.
An L1 cache of 32 KB of SRAM residing in the processor core.
An L2 cache of 512 KB of pipelined-burst SRAM on a separate chip on the
processor card.
Main memory consisting of 32 to 384 MB of SDRAM DIMMs.
ECC support built into the system board that corrects single-bit errors and
detects all multiple-bit errors when ECC DIMMs are installed.
Three full-length 32-bit PCI expansion slots for connecting high-speed PCI
peripherals to the PCI bus—greatly increasing their I/O speeds over the
speeds attainable using the ISA bus.
One full-length 16-bit ISA expansion slot.
One shared full-length PCI expansion slot containing both a PCI and an ISA
expansion-card connector, only one of which can be used at any given
time.
One full-length accelerated graphics port (AGP) expansion slot.
Both PCI and ISA Plug and Play support.
An integrated diskette drive interface that supports a single diskette drive
without the need for a controller card.
Two EIDE interfaces on the PCI bus that support up to two EIDE devices
each. Supported devices include ATA-33 Ultra DMA hard-disk drives,
CD-ROM drives, tape drives, and other removable media.
Support for SCSI hard-disk drives and CD-ROM drives when a SCSI control-
ler card is installed in an expansion-card slot.
A 66-MHz AGP video card with its own dedicated graphics bus that greatly
enhances 3D graphics performance.
These systems are available with and without integrated sound. For sys-
tems with integrated sound, a PCI/ISA advanced audio controller with 3D
positioning and Direct Sound acceleration provides audio functions com-
patible with a Sound Blaster Pro sound card, and a MIDI/game port
provides a connection for a joystick, MIDI keyboard, game pad, or other
game input device.
An integrated high-performance serial port and a bidirectional parallel port.
Two USB connectors, which can simplify connecting peripheral devices.
A PS/2-style keyboard port and a PS/2-compatible mouse port.
Most of these features are briefly described in this chapter. For a complete list
of system features, see “Technical Specifications” found later in this chapter.

System Overview 1-3
When following the procedures in this manual, assume that the locations or
directions relative to the computer are as shown in Figure 1-1.
NOTE: Some service procedures recommend laying the mini tower computer
on its right side to improve service access, but the descriptions in this manual
continue to use the directions shown in Figure 1-1 for the mini tower
computer.
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XVH WKH UHVHW EXWWRQ ZKHQ \RX FDQQRW UHERRW WKH V\VWHP ZLWK WKH
&WUO!$OW!'HO! NH\ FRPELQDWLRQ %HIRUH \RX XVH WKH UHVHW EXWWRQ
WR LQLWLDWH D KDUGZDUH UHVHW FORVH DQ\ RSHQ DSSOLFDWLRQ DQG ILOHV LI
SRVVLEOH
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EUDFNHW RU D PHWDO ILOOHU EUDFNHW LQVWDOOHG (QVXUH WKDW WKH XQRFFX
SLHG GULYH ED\V KDYH D IURQWSDQHO LQVHUW LQVWDOOHG 2PLWWLQJ WKHVH
EUDFNHWV RU LQVHUWV FDQ GLVWXUE WKH QRUPDO DLUIORZ LQ WKH FRPSXWHU
UHVXOWLQJ LQ SRVVLEOH GDPDJH WR V\VWHP FRPSRQHQWV
left side right side
front
back
left side right side
back
Mini Tower Computer
front
Desktop Computer

1-4 Dell Dimension XPS R xxx Systems Service Manual
)LJXUH  ,QWHUQDO 9LHZ RI 'HVNWRS &RPSXWHU
chassis cooling fan
system board
chassis
card-guide assembly
(contains primary
hard-disk drive)
filler brackets
drive cage
diskette-drive interface cable
DC power cables
power supply
drive
bays
(typical)
bezel
power button
hard-disk drive
access indicator
reset button
secondary hard-disk
drive bracket
power indicator

System Overview 1-5
)LJXUH  ,QWHUQDO 9LHZ RI 0LQL 7RZHU &RPSXWHU
)LJXUH  %DFN3DQHO )HDWXUHV 7\SLFDO
chassis cooling fan
system board
chassis
card guide assembly
(contains primary
hard-disk drive)
filler brackets
drive cage
diskette-drive interface cable
DC power cables
power supply
drive
bays
(typical)
bezel
power button
hard-disk drive
access indicator
reset button
secondary hard-disk
drive bracket
video connector
parallelport
connector
mouse
connector keyboard
connector
serial port
connector
security cable
ring
MIDI/game port
connector
*
USB
connectors (2)
line-out jack
*
line-in jack
*
microphone jack
*
voltage selection
switch
AC power
receptacle
*Present only on systems with integrated sound.

1-6 Dell Dimension XPS R xxx Systems Service Manual
$GYDQFHG([SDQVLRQ6XEV\VWHP
This computer system offers an advanced expansion subsystem that can sup-
port a mixture of traditional ISA expansion cards (called
legacy expansion
cards), Plug and Play ISA expansion cards, and PCI expansion cards. Using the
operating system, you can configure the various types of expansion cards and
identify resource conflicts that might arise.
The expansion-card slots include two ISA expansion-card connectors and four
PCI expansion-card connectors. One PCI expansion-card connector and one
ISA expansion-card connector share a single expansion-card slot, so users can
install a maximum of five expansion cards.
In addition to the ISA and PCI expansion-card connectors, there is a connector
for a high-speed, high-resolution 33-MHz PCI video card, or for a 66-MHz AGP
video card that uses its own dedicated graphics bus andsignificantly enhances
3D graphics performance.
(,'(6XEV\VWHP
The EIDE subsystem includes two EIDE interfaces (primary and secondary),
each of which can support up to two EIDE devices such as high-capacity hard-
disk drives, CD-ROM drives, and tape drives.
All EIDE devices should be configured for the Cable Select jumper position,
which assigns master and slave status to devices by their position on the inter-
face cable. In this configuration, the drive attached to the last connector on the
interface cable is the master or boot drive (drive 0) and the drive attached to
the middle connector on the interface cable is the slave drive (drive 1). Refer to
the drive’s documentation for instructions on setting the Cable Select jumper
position.
NOTE: The externally accessible drive bays at the front of the computer are
normally used for diskette drives, CD-ROM drives, or tape drives. The hard-disk
drives should be installed in the internal drive bays as described in the
following subsection. For detailed information about the data storage sub-
system, see Chapter 3, “Installing Drives,” in the
Dell Dimension XPS R xxx
Reference and Troubleshooting Guide
.
+DUG'LVN'ULYH2SWLRQV
A 1-inch-high EIDE or SCSI hard-disk drive is installed in the primary hard-disk
drive bay in the card-guide assembly at the front of the chassis. An optional
1-inch-high EIDE or SCSI hard-disk drive can be installed in the secondary hard-
disk drive bay located near the 3.5-inch diskette drive. SCSI hard-disk drives
require a SCSI controller card installed in an expansion-card slot.
&RPSXWHU6HUYLFH
The following subsections provide service-related information about the
computer.

System Overview 1-7
3RZHU6XSSO\
The 200-W power supply can operate from an AC power source of 115 VAC at
60 Hz or 230 VAC at 50 Hz. The power supply provides the DC operating volt-
ages and currents listed in Table 1-1.
NOTE: The power supply produces DC voltages only under its loaded
condition. The DC power cable connectors must be connected to their corre-
sponding power input connectors on the system board or drives in order to
measure these voltages.
'&3RZHU'LVWULEXWLRQ
Figures 1-5 through 1-9 provide the following information about DC power
distribution:
Power-supply cable identification
Typical DC power connections for diskette, tape, CD-ROM, and hard-disk
drives
Power distribution to sockets and connectors on the system board
Pin assignments of DC power connectors
7DEOH  '& 9ROWDJH 5DQJHV
9ROWDJH 5DQJH 0D[LPXP 2XWSXW &XUUHQW
+3.3 VDC +3.14 to +3.47 VDC 14.00 A
1
+5 VDC +4.90 to +5.25 VDC 22.00 A
1
–5 VDC –4.50 to –5.50 VDC 0.300 A
+12 VDC +11.40 to +12.60 VDC 6.00 A
2
–12 VDC –10.80 to –13.20 VDC 0.300 A
+5 VSB
3
+4.75 to +5.25 VDC 0.010 A
1
The combined load on the +3.3-VDC and +5-VDC outputs cannot exceed 140 W.
2
The +12-VDC output line can withstand surges of up to 11.0 A to support disk start-up
operations.
3
The +5 VSB (volts standby) is sometimes called “flea power.”

1-8 Dell Dimension XPS R xxx Systems Service Manual
)LJXUH  '& 3RZHU &DEOHV
P1
P7
P2
P3
P6
P5
P4

System Overview 1-9
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+3.3 P2
secondary
hard-disk drive
(uses Y-cable)
+5 VDC
–12 VDC
GND
+12 VDC
+3.3
+3.3
GND
GND
–5 VDC
–5 VDC
+5 VDC
+12 VDC
power
supply
PWRGOOD
P1
3.5-inch drives
(second drive
uses Y-cable)
3.5-inch
diskette drive
5.25-inch
drive
primary
hard-disk drive
ISA
connectors
PCI
connectors
1.5-V
converter
microprocessor
SEC cartridge
connector
system board
P3
P5
P4
P6
+5 VSB
PSON#
power
switch
GND
PSON#
+5 VSB
battery RTC
GND
+12 VDC
GND
+2.1–2.8 VDC
GND
KEYBD
MSE
GND
GND
+5 VDC
+5 VDC
fuse
P7
POWER 3.3
FAN1
5.25-inch
drive
GND
+5 VDC
GND
GND
+5 VDC USB0,
USB1
fuse
+3.3
GND
BANK 0
2.1–2.8-V
converter
+1.5 VDC
DIMMs
BANK 1
BANK 2

1-10 Dell Dimension XPS R xxx Systems Service Manual
'&3RZHU&RQQHFWRU3LQ$VVLJQPHQWV
The power-supply output voltages can be measured at the back (wire side) of
the DC power connectors without disconnecting them. Figures 1-7 through 1-9
show the wire side of the connectors.
1
Pin 5 — PWRGOOD is a status signal generated by the power supply to notify the system
that the DC operating voltages are within the ranges required for proper system operation.
2
Pin 11 — PSON# is activated by pressing and releasing the power button while the power
supply is in its standby state. This action connects the power supply’s PSON# input to
ground, thereby switching the power supply to its full-on condition.
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11
1
PWRGOOD1
(gray)
–12 VDC (blue)
+12 VDC (yellow)
+5 VFP (purple)
common (black)
2 345678910
12 13 14 15 16 17 18 19 20
P1
+5 VDC (red)
+5 VDC (red)
+5 VDC (red)
+5 VDC (red)
+5 VDC (red)
+5 VDC (red)
common (black)
common (black)
common (black)
PSON#2(brown)
common (black)
common (black)
common (black)
–5 VDC (white)
not connected

System Overview 1-11
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)LJXUH  '& 3RZHU &RQQHFWRU 3
1 2 3 4 +5 VDC (red)
common (black)
common (black)
+12 VDC (yellow)
P2,
P3,
P5, P6
1 2 3 4
+5 VDC (red)
common (black)
common (black)
+12 VDC (yellow)
P4
4 5 6 +3.3 VDC (orange)common (black) 321
+3.3 VDC (orange)common (black)
common (black) +3.3 VDC (orange)
P7

1-12 Dell Dimension XPS R xxx Systems Service Manual
6\VWHP%RDUG
The subsections that follow provide service-related information about system
board components.
)LJXUH  6\VWHP %RDUG )HDWXUHV
parallel port
connector (PARALLEL)
keyboard connector (KEYBD)
ISA expansion-card
connectors (ISA1 and ISA2)
mouse connector (MSE)
microprocessor
SEC cartridge
connector (J4J1)
serial port
connector (COM1)
PCI expansion-card
connectors (PCI1,
PCI2, PCI3, and PCI4)
MIDI/game port
connector (GAME)
*
integrated audio controller
jacks (LINE OUT, LINE IN,
and MIC IN)*
diskette-drive
interface connector
(FLOPPY)
secondary EIDE
channelconnector
(SEC IDE)
DIMM sockets
(BANK 0, BANK 1,
BANK 2)
configuration
jumper (J8A1)
chassis cooling fan
connector (J8M1)
control panel
connector (J8H1)
3.3-V power input
connector (3.3)
USB connectors
(USB0, USB1)
SCSI hard-disk drive
access indicatorcable
connector (J8J1)
accelerated graphics
port connector (AGP)
power input
connector
(POWER)
battery socket (B7C1)
modem audio cable connector
for using audio system as
speaker phone (TELEPH)
*
speaker (U8A1)
expansion header (PC/PCI)
* For systems with integrated sound
CD-ROM drive audio
cable connector (CD)
*
primary EIDE channel
connector (PRI IDE)
microprocessor
fan connector
(J4M1)
auxiliary line-in audio
connector (AUX IN)
*
front of computer