Dell OptiPlex N, OptiPlex N Series Service Manual

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®

____________________

Information in this manual is subject to change without notice.

 1997-1998 Dell Computer Corpora tion. All rights reserved.

Reproduction in any manner whatsoever without the written permission of Del l Computer Corporation is strictly forbidden.
Trademarks used in this text: Dell, the DELL logo, and OptiPlex are registered trademarks of Dell Computer Corporation; Intel and Pentium are registered trademarks

and MMX and EtherExpress are trademarks of Intel Corporation; MS-DOS is a registered tradem ark of Microsoft Corpora t ion; IBM is a registered trademark of
International Busin ess Ma chines Corporation; 3C om is a re gistered trademark of 3Com Corporation.

Other trademarks and tr ade names may be used in this document to refer to either the ent it ie s cl ai m ing the marks and names or their products. Dell Computer
Corporation disclai m s any pr oprietary interest in trademarks and trade name s other than its own.

February 1998 P/N 57646 Rev. A01

Contents

Chapter 1

System Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

System Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Expansion-Card Slot. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Hard-Disk Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Enhanced Dual-Interface EIDE Subsystem . . . . . . . . . . . . . . . . . . . . . . . 1-4

Built-In Video Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Optional Built-In NIC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

Stand for Vertical Orientation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

Computer Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Computer Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Pin Assignments for the DC Power Connectors. . . . . . . . . . . . . . . . . 1-7

DC Power Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

System Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10

Main Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11

System Board Jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11

Interrupt Assignments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13

DMA Channel Assignments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14

Technical Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15

Chapter 2

Basic Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Initial User Contact. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

External Visual Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Observing the Boot Routine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Server-Based Diagnostics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Hard-Disk–Based Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Internal Visual Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

v

Diskette-Based Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Connecting the External Diskette Drive. . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Running the Diskette-Based Diagnostics. . . . . . . . . . . . . . . . . . . . . . . . . 2-9

Getting Help. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

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 . . . . . . . . . . . . . . . . . . . 4-1

Recommended Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Precautionary Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

Stand for Vertical Orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Computer Cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

Hard-Disk Drive. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7

System Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

System Board Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9

Expansion-Card Cage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10

Expansion Card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11

Riser Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12

DIMMs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13

Microprocessor/Heat Sink Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14

System Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16

System Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17

Appendix A

System Setup Program . . . . . . . . . . . . . . . . . . . . . . . . . .A-1

System Setup Screens. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-2

Index

Figures

Figure 1-1. Computer Orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Figure 1-2. Front-Panel Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Figure 1-3. Internal View. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

vi

Figure 1-4. Riser Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Figure 1-5. NIC Connector on I/O Panel . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

Figure 1-6. DC Power Connector P1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

Figure 1-7. DC Power Connector P2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

Figure 1-8. DC Power Connector P3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

Figure 1-9. DC Power Cables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

Figure 1-10. DC Power Distribution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9

Figure 1-11. System Board Components . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10

Figure 1-12. System Board Jumpers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11

Figure 2-1. External Diskette Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Figure 4-1. Optional Stand Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Figure 4-2. Computer Cover Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Figure 4-3. Service Access Lock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Figure 4-4. Control Panel Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

Figure 4-5. Hard-Disk Drive Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7

Figure 4-6. System Power-Supply Removal. . . . . . . . . . . . . . . . . . . . . . . . 4-8

Figure 4-7. System Board Components . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9

Figure 4-8. Expansion-Card Cage Removal. . . . . . . . . . . . . . . . . . . . . . . 4-10

Figure 4-9. Expansion-Card Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11

Figure 4-10. Riser Board Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12

Figure 4-11. DIMM Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13

Figure 4-12. DIMM Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13

Figure 4-13. Microprocessor Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14

Figure 4-14. Microprocessor Securing-Clip Removal . . . . . . . . . . . . . . . . 4-15

Figure 4-15. System Battery Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16

Figure 4-16. System Board Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17

Figure A-1. System Setup Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-2

Figure A-2. Sample Device List Screen . . . . . . . . . . . . . . . . . . . . . . . . . . .A-6

Tables

Table 1-1. DC Voltage Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Table 1-2. System-Board Jumper Descriptions. . . . . . . . . . . . . . . . . . . . 1-12

Table 1-3. Interrupt Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13

Table 1-4. DREQ Line Assignments. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14

Table 1-5. Technical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15

Table 3-1. POST Beep Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Table 3-2. System Error Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

Table A-1. System Setup Categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-3

vii

ead This First

R

A prerequisite for using this manual to service Dell computer systems is a
basic knowledge of IBM®-compatible PCs and prior training in IBM­compatible PC troubleshooting techniques. In addition to information
provided in this manual a nd the User’s Guide that came with the system, Dell
provides the Diagnostics and T roubleshooting Guide for troubleshooting pro­cedures and instructions on using the Dell diagnostics to test the computer
system.

arnings, Cautions, and Notes

W

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:

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.

NOTE: A NOTE pr o v ides helpful information about using the computer system.

viii

Chapter 1

System Overview

he Dell

T

designed for centrally managed network operation. These computers have a
small-footprint, locked chassis with no externally accessible drives.

The OptiPlex N computers use the Intel® Pentium® microprocessor with
MMX™ technology. The microprocessor is installed in a type 7 ZIF socket,
allowing 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 fre­quency. The microprocessors for Dell OptiPlex N computers operate at a
frequency of 166 MHz, 200 MHz, or 233 MHz, derived from a system clock
frequency of 66 MHz.

These Dell computers incorporate the high-performance PCI expansion bus.
This bus is built into the system board, which also integrates the micro­processor, memory controller, hard-disk drive controller, video controller, and
other elements of the basic computer.

®

OptiPlex® N computers are high-speed, upgradable computers

System Overview 1-1

S

left

side

front

right

side

back

ystem Features

In addition to the standard features found in a traditional personal computer , the
Dell OptiPlex N computers include the following new and/or advanced
features:

One PCI expansion-card slot on a riser board

•

One EIDE hard-disk drive

•

Ultra DMA/33 EIDE interface for hard-disk drive transfer rates of up to

•

33 MB/sec
Support for connecting an external diskette drive for troubleshooting

•

purposes
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 10/100-Mbps Ethernet NIC

•

Optional NIC expansion card providing Wakeup On LAN capability

•

Integrated Universal Serial Bus (USB) controller with two USB-compliant

•

connectors
SMART-compliant hard-disk drive and SMART support in the system

•

BIOS, which provides notification at system start-up if the hard-disk drive
has become unreliable

Server-based, hard-disk–based, and diskette-based diagnostics capabilities

•

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.

Figure 1-1. Computer Orientation

1-2 Dell OptiPlex N Systems Service Manual

Figures 1-2 and 1-3 show the system’ s front-panel features and internal features,
respectively .

power button

power indicator

hard-disk drive
access indicator

Figure 1-2. Front-Panel Features

padlock ring

security access lock
security cable slot

parallel port
connector

serial port 1
connector

mouse connector

keyboard connector

USB connectors (2)

serial port 2 connector

video connector

power supply

NIC connector (optional)

DC power cable

expansion-card slot

AC power
receptacle

EIDE cable

hard-disk drive

expansion-card
cage

Figure 1-3. Internal View

System Overview 1-3

Expansion-Card Slot

PCI1

connector

power LED

Wakeup On LAN

power connector

The computer has one PCI expansion-card connector on the riser board (see
Figure 1-4). The computer automatically assigns any required memory space,
IRQ lines, and DMA channels to an installed PCI expansion card during system
start-up. The Wakeup On LAN power connector on the riser board supports an
optional NIC expansion card with Wakeup On LAN capability. The power LED
illuminates when DC power is applied to the riser board.

Figure 1-4. Riser Board

Hard-Disk Drive

One 1-inch-high EIDE hard-disk drive can be mounted to the top of the
expansion-card cage.

Enhanced Dual-Interface EIDE Subsystem

The EIDE subsystem provides two mode-4, DMA bus-mastered EIDE inter­faces, each of which can support up to two EIDE devices. The EIDE controller
attaches to the high-speed PCI local bus. Any attached EIDE device should be
configured for the Cable Select jumper position. The computer’s boot drive
should be connected to the primary EIDE interface (IDE1).

NOTE: Although the OptiPlex N system board supports up to four EIDE
devices, no devices other than the internal hard-disk drive should be connected.

Built-In Video Controller

The video subsystem consists of a high-speed, high-resolution S3 Trio 64V2
86C785 video controller built into the system board. The video controller con­nects to the PCI bus, which operates at a frequency of 33 MHz.

The built-in video controller includes 2 MB of video memory built into the sys­tem board.

1-4 Dell OptiPlex N Systems Service Manual

Optional Built-In NIC

The Dell OptiPlex N computers offer an optional integrated 10/100-Mbps
3Com® PCI 3C905 Ethernet NIC subsystem. The NIC provides all the func­tions of a separate 3Com 3C905 network expansion card and supports the
100BASE-TX Ethernet standards. Category 5 wiring and connections must be
used.

The integrated NIC does not support the Wakeup On LAN feature. Wakeup
On LAN capability is provided by an optional NIC expansion card such as the
Intel EtherExpress™ PRO/100M.

The NIC subsystem connects to the Ethernet network through an RJ45 connec­tor on the back panel of the computer.

link integrity
indicator

activity
indicator

NIC connector

Figure 1-5. NIC Connector on I/O Panel

On computers with the optional built-in NIC, the NIC (RJ45) connector and
NIC interface circuitry are mounted on the system board. The connector
includes the following indicators (see Figure 1-5):

A yellow activity indicator flashes when the computer is transmitting or

•

receiving network data. (A high volume of network traffic may make this
indicator appear to be in a steady “on” state.)

A green link integrity indicator lights up when there is a good connection

•

between the network and the NIC. When the green indicator is off, the com­puter is not detecting a physical connection to the network.

“Network Considerations” in the online Network Administrator’s Guide pro-
vides instructions for connecting the computer to, and configuring it for use on,
an Ethernet network.

Stand for Vertical Orientation

The computer can be used in a vertical orientation by attaching an available
stand to the left side of the computer.

System Overview 1-5

C

omputer Service

The following subsections provide service-related information about the
computer.

Computer Power Supply

The Dell OptiPlex N computers have an 80-W computer power supply. The
power supply can operate from an AC power source of 115 VAC at 60 Hz or
230 VAC at 50 Hz. The computer power supply provides the DC operating volt­ages and currents listed in Table 1-1.

NOTE: The power supply produces DC voltages only under its loaded condi­tion. Therefore, when you measure these voltages, the DC power connectors
must be connected to their corresponding pow er input connectors on the system
board and hard-disk drive.

.

Table 1-1. DC Voltage Ranges

Voltage Range Maximum Output Current

+3.3 VDC +3.135 to +3.465 VDC
+5 VDC +4.75 to +5.25 VDC
+12 VDC +11.40 to +12.60 VDC

6.0 A

12.0 A

1.0 A

1

1

2

1

–12 VDC –10.80 to –13.20 VDC 0.5 A
+5 VFP

1

The combined load on the +5-VDC and +3.3-VDC outputs should not exceed 65 W.

2

Withstands surges of up to 3.0 A to support disk start-up operations.

3

VFP (volts flea power) — sometimes called “standby power.”

3

+4.75 to +5.25 VDC 1.2 A

1-6 Dell OptiPlex N Systems Service Manual

Pin Assignments for the DC Power Connectors

The power-supply output voltages can be measured at the back (wire side) of
the connectors without disconnecting them. Figures 1-6 through 1-8 show the
wire side of the connectors.

open

common (black)

common (black)
common (black)

1

PSON#

(grey)

11

12 13 14 15 16 17 18 19 20

+5 VDC (red)

+5 VDC (red)
+5 VDC (red)

2

TFSC

(brown)

+5 VDC (red)

P1

234 5678 910

1

+5 VDC (red)

common (black)

+5 VDC (red)

common (black)

3

PWRGOOD

1

Pin 11 — PSON# should measure between +4 and +5 VDC except when the power button

(orange)

common (black)
common (black)

–12 VDC (blue)
+12 VDC (yellow)
+5 VFP (purple)

on the front panel is pressed, taking PSON# to its active-low state.

2

Pin 19 — Thermal fan-speed control (TFSC) is a power-supply input signal used to control
the power-supply fan speed.

3

Pin 5 — PWRGOOD should measure between +4 and +5 VDC when the power supply is
on to indicate that all power-supply output voltages are within the ranges specified in
Table 1-1.

Figure 1-6. DC Power Connector P1

1234

5

Figure 1-7. DC Power Connector P2

P2

6

+3.3 VDC (blue/white)

+3.3 VDC (blue/white)
+3.3 VDC (blue/white)

common (black)
common (black)
common (black)

System Overview 1-7

Figure 1-8. DC Power Connector P3

1 2 3 4

+5 VDC (red)

common (black)

common (black)

+12 VDC (yellow)

P3

P3P2P1

DC Power Distribution

Figures 1-9 and 1-10 provide the following information about DC power
distribution:

Power-supply connector identification

•

Power cable connection for the hard-disk drive

•

Power distribution to sockets and connectors on the system board

•

Figure 1-9. DC Power Cables

1-8 Dell OptiPlex N Systems Service Manual

keyboard
controller

+3 VDC

system board

computer

power supply

internal

hard-disk drive

PWRGOOD
PSON#
+5 VFP

+5 VDC
+12 VDC
–12 VDC

+3.3 VDC

P3

P1 POWER_1

PSON#
+5 VFP

+5 VDC
+12 VDC
–12 VDC

POWER_2

P2

main memory

sockets

DIMM_A

DIMM_B

MICROPROCESSOR

core VCC +2.1 to +3.5 VDC

power

management

logic

+3.3 VDC

RTC/

NVRAM

+3.3 VDC
+5 VDC
+12 VDC
–12 VDC

RISER

+12 VDC

+5 VFP

+5 VDC
+5 VDC

+5 VDC

+5 VDC

processor core

regulator

battery

FAN

PANEL

USB

KYBD

MOUSE

riser board

+3.3 VDC
+5 VDC
+12 VDC
–12 VDC

fuses (2)

PCI1

Figure 1-10. DC Power Distribution

System Overview 1-9

System Board

The subsections that follow provide service-related information about the sys­tem board and its components (see Figure 1-11).

NIC connector
(ENET)

battery socket
(BATTERY)

system board
jumpers

riser board
connector
(RISER)

video connector
(MONITOR)

serial port 2
connector
(SERIAL2)

USB connectors (2)
(USB)

keyboard/mouse
connectors (stacked)
(KYBD/MOUSE)

parallel/serial port 1
connectors (stacked)
(PARALLEL/SERIAL)

microprocessor socket
(MICROPROCESSOR)
(pin-1 corner)

DIMM sockets (2)
(DIMM_A)

main power input
connector (POWER_1)

3.3-V power input
connector (POWER_2)

front of computer

primary EIDE
interface connector
(IDE1) (pin-1 corner)

secondary EIDE
interface connector
(IDE2) (pin-1 corner)

Figure 1-11. System Board Components

diskette/tape drive
interface connector
(DSKT) (pin-1 corner)

control panel
connector (PANEL)

1-10 Dell OptiPlex N Systems Service Manual

Main Memory

The two DIMM sockets on the system board can accommodate combinations of
16-, 32-, 64-, and 128-MB DIMMs up to a total memory capacity of 256 MB.
Although 64-bit nonparity EDO DIMMs are recommended, 72-bit parity
DIMMs can also be installed. The standard main memory is 16 MB of high­speed (60-ns) nonparity memory. For optimum performance, install DIMMs in
consecutive sockets starting with socket DIMM_A.

System Board Jumpers

Figure 1-12 shows the location of the jumper blocks on the system board. See
Table 1-2 for the jumper descriptions and settings.

jumpered

unjumpered

Figure 1-12. System Board Jumpers

System Overview 1-11

Table 1-2. System-Board Jumper Descriptions

Jumper Description Settings

133 Reserved Do not install jumper.
166

*

Microprocessor
speed

Install jumper if the microprocessor’s
internal speed is 166 MHz; otherwise the
jumper should not be installed.

200

*

Microprocessor
speed

Install jumper if the microprocessor’s
internal speed is 200 MHz; otherwise the
jumper should not be installed.

233

*

Microprocessor
speed

Install jumper if the microprocessor’s
internal speed is 233 MHz; otherwise the
jumper should not be installed.

PSWD Password

enable or
disable

Install to enable the password features.
Remove the PSWD jumper and boot the
computer to remove an existing password.

BIOS Reserved Do not install jumper.

* One set of the speed jumper pins must have a jumper plug installed; otherwise, the computer will

operate at an undetermined speed.

1-12 Dell OptiPlex N Systems Service Manual

I

nterrupt Assignments

Table 1-3 shows the assignment or availability of IRQ lines.

Table 1-3. Interrupt Assignments

IRQ Line Used By/Available

IRQ0 Generated by system timer.
IRQ1 Generated by keyboard controller to indicate that keyboard’s out-

put buffer is full.

IRQ2 Generated internally by interrupt controller to enable IRQ8

through IRQ15.

IRQ3 Generated by super I/O controller to indicate that the device con-

nected to serial port 2 (COM2 or COM4) requires service.

IRQ4 Generated by super I/O controller to indicate that the device con-

nected to serial port 1 (COM1 or COM3) requires service.
IRQ5 Available for use by an expansion card.
IRQ6 Generated by super I/O controller to indicate that diskette

requires service.
IRQ7 Generated by super I/O controller to indicate that device con-

nected to parallel port requires service.
IRQ8 Generated by keyboard controller for each tick of RTC.
IRQ9 Available for use by video controller to indicate that the video or

monitor requires service.
IRQ10 Available for use by an expansion card.
IRQ11 Available for use by an expansion card.
IRQ12 Generated by keyboard controller to indi cate that mouse’s output

buffer is full.
IRQ13 Generated by math coprocessor to indicate coprocessor error.
IRQ14 Generated by hard-disk drive connected to primary EIDE port to

indicate that drive requires service. If the EIDE controller is dis-

abled, this line is available for other use.
IRQ15

* Although the OptiPlex N system board supports up to four EI DE devices, no devices other than

the internal hard-disk drive should be connected.

Generated by device connected to secondary EIDE port to

*

indicate that device requires service. If the EIDE controller is not

in use, this line is available for other use.

System Overview 1-13

D

MA Channel Assignments

Table 1-4 shows the assignment or availability of DREQ lines.

Table 1-4. DREQ Line Assignments

DREQ Line Used By/Available

DREQ0 Available
DREQ1 Available
DREQ2 Generated by super I/O controller to initiate DMA cycle for

attached diskette drive
DREQ3 Available
DREQ4 Generated by bus controller chip to activate second DMA

controller
DREQ5 Available
DREQ6 Available
DREQ7 Available

NOTES: The video controller and optional built-in NIC controller are assigned available
DMA channels automatically during computer start-up.

If the parallel port is in ECP mode, it uses one of the available DREQ lines.

1-14 Dell OptiPlex N Systems Service Manual

T

echnical Specifications

Table 1-5 provides technical specifications for the OptiPlex N systems.

z

Table 1-5. Technical Specifications

Microprocessor

Microprocessor type . . . . . . . Intel Pentium microprocessor with MMX

technology

Microprocessor speed . . . . . . 166, 200, or 233 MHz

Internal system clock . . . . . . 66 MHz

Internal cache . . . . . . . . . . . . 32 KB (16-KB data cache; 16-KB instruc-

tion cache)

Math coprocessor . . . . . . . . . internal to the microprocessor

System Information

System chip set . . . . . . . . . . . Intel 430TX PCI chip set

Data bus width . . . . . . . . . . . 64 bits

Address bus width. . . . . . . . . 32 bits

DMA channels . . . . . . . . . . . seven

Interrupt levels . . . . . . . . . . . 15

Flash EPROM (BIOS) . . . . . 2 Mb (256 KB)

Expansion Bus

Bus type . . . . . . . . . . . . . . . . PCI (complies with PCI specification 2.1)

Bus speed . . . . . . . . . . . . . . . 33 MHz

PCI expansion-card connectors

one

NIC

NIC . . . . . . . . . . . . . . . . . . . . optional integrated 3Com PCI 3C905 net-

work controller, operating at 10 or

100 Mbps

System Overview 1-15

Table 1-5. Technical Specifications

Memory

(continued)

Architecture . . . . . . . . . . . . . 64-bit (nonparity) or 72-bit (parity) EDO,

noninterleaved

DIMM sockets . . . . . . . . . . . two (gold contacts)

DIMM capacities . . . . . . . . . 16-, 32-, 64-, and 128-MB EDO parity or

nonparity (recommended)

Standard RAM . . . . . . . . . . . 16 MB

Maximum RAM. . . . . . . . . . 256 MB

Cache memory . . . . . . . . . . . 512-KB pipelined-burst, direct-mapped,

write-back SRAM

BIOS address . . . . . . . . . . . . F0000h

Drives

Internal hard-disk drive . . . . one 3.5-inch, 1-inch high EIDE hard-disk

drive

Video

Video type. . . . . . . . . . . . . . . S3 Trio 64V2 86C785 built-in SVGA

controller attached to the PCI bus

Video memory . . . . . . . . . . . 2 MB

Maximum video

resolution. . . . . . . . . . . . . . . .

1280 x 1024 pixels with 256 colors,

noninterlaced; 1024 x 768 pixels with

65,536 colors, noninterlaced

Ports

Externally accessible:

Serial (DTE). . . . . . . . . . two 9-pin connectors (16550-compatible)

Parallel . . . . . . . . . . . . . . one 25-hole connector (bidirectional)

Video . . . . . . . . . . . . . . . one 15-hole connector

PS/2-style keyboard . . . . 6-pin mini-DIN connector

PS/2-compatible

mouse . . . . . . . . . . . . . . . 6-pin mini-DIN connector

NIC (optional) . . . . . . . . RJ45 connector

USB . . . . . . . . . . . . . . . . two USB-compliant connectors

1-16 Dell OptiPlex N Systems Service Manual