HP Net PC 20 Manual

Familiarization Guide
HP Small PC 20
This guide is for experienced technicians who have already
completed an HP PC family training course. It is a self-
paced training guide designed to train you to repair the PC.
It contains information specific only to the repair of these
PCs. For more information about upgrading the PC, refer
to the documentation supplied with the PC or to HP’s Sup-
port Web site at http://www.hp.com/go/thinclientsupport.
HP Net PC 20

Notice
The information contained in this document is subject to change without notice.
Hewlett-Packard makes no warranty of any kind with regard to this
material, including, but not limited to, the implied warranties of
merchantability and fitness for a particular purpose.
Hewlett-Packard shall not be liable for errors contained herein or for incidental
or consequential damages in connection with the furnishing, performance, or use
of this material.
This document contains proprietary information that is protected by copyright.
All rights are reserved. No part of this document may be photocopied,
reproduced, or translated to another language without the prior written consent
of Hewlett-Packard Company.
Windows® is a U.S. registered trademark of the Microsoft Corporation.
CeleronTM is a trademark, and Pentium® is a U.S. registered trademark of the
Intel Corporation.
Hewlett-Packard France
Thin Client Operation
38053 Grenoble Cedex 9
France
1998 Hewlett-Packard Company

Contents
3
Electrostatic Discharge Warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Care of Hard Disk Drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
HP PC Product Comparison. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Some Product Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
PC Package. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
System Board and Backplane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
System Board Jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Removing and Replacing the Cover . . . . . . . . . . . . . . . . . . . . . . . . . 14
Removing the Front Panel Chassis . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Installing a Hard Disk Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Installing a Slim CD-ROM Drive. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Installing a Slim Floppy Disk Drive. . . . . . . . . . . . . . . . . . . . . . . . . . 21
Installing Memory Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Removing and Replacing the Power Supply Unit . . . . . . . . . . . . . . 24
Removing and Replacing the System Board. . . . . . . . . . . . . . . . . . . 25
Support Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Flashing the Latest Version of the System BIOS. . . . . . . . . . . . . . . . . . . 26
Accessing the BIOS Setup Program. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Viewing Power On Self Test (POST) Information. . . . . . . . . . . . . . . . . . 26
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Contents
4
Where to Find More Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Complete the Questionnaire to Check Your Understanding . . . . . 28
Answers and Explanations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

5
Electrostatic Discharge Warning
Electrostatic Discharge Warning
Electrostatic Discharge (ESD) can damage processors, memory, disks, accessory
boards and other components.
When installing or replacing a component:
1Do not take the new component out of its ESD package before connecting your
wrist strap and ESD mat to a suitably earthed (grounded) point.
2Do not forget to use the ESD package provided with the new part to return the
old part. The ESD package is conductive and is easy to recognize from its label.
ESD Label

6
Care of Hard Disk Drives
Care of Hard Disk Drives
Hard disk drives are delicate and are very sensitive to shocks or vibration. When
installing a hard disk accessory, be careful not to drop or knock the drive. Any
shock may damage the drive and prevent it from functioning correctly.
Hard disk drives already installed in HP PCs are also sensitive to shocks. If the
PC’s system unit is knocked or dropped accidentally, this may cause damage to
installed hard disk drives.
Avoid striking the PC
Don’t move the PC
when powered on
Don’t knock the hard
disk during installation

7
HP PC Product Comparison
HP PC Product Comparison
The following table shows the product features of the HP Small PC 20 / HP Net
PC 20 and the HP Vectra VE 8 PC.
Component HP Vectra VE 8/xxx PC HP Small PC 20 / HP Net PC 20
Microprocessor Intel Pentium®II for Slot 1, 266, 333, 350, or
400 MHz, 32 KB of level-1 cache memory, 512
KB of level-2 cache memory
Intel Pentium II for Slot 1, 333 MHz, 32 KB of
level-1 cache memory, 512 KB of level-2 cache
memory
OR
Intel CeleronTM, 266, 300A or 333 MHz, 32 KB
of level-1 cache memory, 128 KB of level-2
cache memory in 300A and 333 MHz models, 0
KB of level-2 cache in 266 MHz models
Chipset Intel 440BX AGPset, 66 or 100 MHz bus speed.
● AGP-enabled (Accelerated Graphics Port) for
enhanced graphics performance in Intel Pentium
II-based systems
● ACPI (Advanced Configuration and Power
Interface) support
● Ultra DMA/33 hard disk support (on Primary
and Secondary IDE channels)
● SDRAM memory allows real-time data transfer
from the processor, eliminating bottlenecks and
improving overall system performance
Intel 440EX AGPset, 66 MHz bus speed.
● AGP-enabled (Accelerated Graphics Port) for
enhanced graphics performance in Intel Pentium
II and Celeron-based systems
● ACPI (Advanced Configuration and Power
Interface) ready
● Ultra DMA/33 hard disk support
● SDRAM memory allows real-time data
transfer from the processor, eliminating
bottlenecks and improving overall system
performance
Memory 32 or 64 MB installed, 384 MB maximum of non-
ECC SDRAM in three DIMM sockets 32, 64, or 128 MB installed, 256 MB maximum of non-ECC SDRAM in two DIMM sockets
Hard Disks 3.2, 4.3, or 6.4 GB Ultra ATA SMART II 3.2 or 6.4 GB Ultra ATA SMART
Flexible disk drive 3.5-inch, 1.44 MB capacity Slim 3.5-inch, 1.44 MB capacity (some models)
CD-ROM 32X IDE (some models) 12.7 mm Slim 24X IDE (some models)
Audio Interface Sound Blaster Pro compatible (Aztech) audio
board (some models)
Integrated ISA-based CrystalClear CS4235 3D
Sound Blaster, Sound Blaster Pro and Windows
Sound System compatible
LAN Interface 3Com 905B-TX or Intel 10/100Base-T LAN board Integrated Intel 10/100BT with RPO/WuOL
Graphics Matrox Productiva M100 AGP board, 4 MB EDO
(not upgradeable) on AGP bus
Integrated AGP-based ATI RAGE IIC/PRO AGP
controller with onboard 4 MB SGRAM (not
upgradeable)
Operating Systems Windows NT4 (Service Pack 3) or Windows 95
(SR 2.5)
Windows NT 4, Windows 95 or Windows 98

8
HP PC Product Comparison
Connectors 2 serial, 1 parallel, keyboard, mouse, 2 stacked
USB, 15-pin VGA
2 serial, 1 parallel with ECP/EPP, keyboard,
mouse, 2 USB, 1 RJ45 LAN, 1 D-sub 15-pin
VGA, 3 audio: 1 Mic-in, 1 Line-in, and 1 Line-out
Expandability
(desktop)
5 drive shelves: 3 front-access and 2 internal
Accessory Slots: 4 PCI, 1 ISA,
1 ISA/PCI combination
3 drive shelves: 2 front-access and 1 internal
Accessory slots: 1 PCI and 1 PCI/ISA
combination. (The HP Net PC 20 does not have
an ISA slot.)
(The minitower model is the same as the
desktop model, but on a stand.)
Expandability
(minitower) 6 drive shelves: 4 front-access and 2 internal
Accessory Slots: 4 PCI, 1 ISA,
1 ISA/PCI combination
BIOS AMI standard BIOS AwardBIOS with 2 MB Flash EEPROM, DMI 2.0
compliant
Power Supply Manually switched 115/230 VAC, 145 W
continuous output
100 to 240 VAC (manually switched), 85 Watt
Input/Output Cables Primary IDE cable: Ultra ATA
Secondary IDE (CD-ROM) cable: Standard IDE
Floppy disk drive cable
Note: both IDE channels are Ultra ATA
Primary IDE cable: Ultra ATA
Secondary IDE (CD-ROM) cable: Standard IDE
slim cable
Floppy disk drive cable
System Management DMI 2.0 / SMBIOS 1.x, HP TopTools 3.0, HP
DiagTools 2.0
DMI 2.0, ACPI-ready, TopTools Console,
OpenView DTA
Component HP Vectra VE 8/xxx PC HP Small PC 20 / HP Net PC 20

9
Some Product Features
Some Product Features
Intel Celeron Processor The Intel Celeron processor 333, 300A and 266 MHz provides ideal performance
for applications running on operating systems such as Windows 95. All Intel
Celeron processors are based on Intel’s 0.25 micron CMOS process technology.
The Intel Celeron processor also benefits from the same P6 microarchitecture
core as the Pentium II processor.
Intel 440EX AGPset
Features
This Intel chipset, which is based on the Intel 440LX chipset, is optimized for
Intel Celeron processor-based systems. It provides ACPI-compliance to permit
increased manageability across the corporate network. It is AGP-enabled for
enhanced graphics performance. The chipset also provides support for Ultra
DMA/33. No Error Correcting Code (ECC) support is provided.
Bus Details
Video: ATI RAGE IIC/PRO
AGP Chip
The system comes with an integrated AGP-based ATI RAGE IIC/PRO AGP
controller chip. This VGA controller offers output pixel data rates with non-
interlaced screen resolutions of up to 1600x1200x65k colors at a refresh rate of
76Hz (4 MB). The AGP controller enables the system to have a higher
performance under Windows and other GUI (Graphics User Interface)
environments, plus optimizations which result in even more impressive 2D and 3D
performance.
The RAGE IIC/PRO delivers 3D performance unmatched in its class, along with a
comprehensive list of 3D features including perspectively correct texturing, mip-
mapping, bilinear and trilinear filtering, z-buffering, video texturing, Gouraud
shading, and alpha blending.
The RAGE IIC/PRO incorporates excellent video support, suitable for MPEG-2
content and video conferencing acceleration. In addition to offering increased
performance and design flexibility, the RAGE IIC/PRO adds full PCI Power
Management support.
Bus Speed Size Transfer Rate
Host (Front Side Bus, Processor-
Local, System)
66 MHz 64 bit 528 MB/sec
AGP 66 MHz (double-
clocked)
32 bit 528 MB/sec
PCI 33 MHz 32 bit 132 MB/sec
ISA 8.25 MHz 16 bit 16 MB/sec

10
Some Product Features
Audio: CrystalClear
CS4235 Chip
The onboard CrystalClear CS4235 chip includes an integrated FM synthesizer and
a Plug-and-Play interface. In addition, it includes hardware master volume control
as well as extensive power management and 3D sound technology. It is compatible
with the Microsoft Windows Sound System standard and will run software written
to the Sound Blaster and Sound Blaster Pro interfaces. It is fully compliant with
Microsoft's PC97 and PC98 audio requirements.
LAN: Intel 82558 Chip The onboard Intel 82558 chip is a fully integrated 10BASE-T/100BASE-TX LAN
controller. It consists of both the MAC controller and the 10/100 Mbps physical
layer interface. Its true 32-bit architecture enables it to perform high speed data
transfers on the PCI bus using four DMA channels. Its sophisticated microcode-
based engine enables the 82558 chip to process high level commands and perform
multiple operations without CPU intervention. Its 3 Kbyte Transmit and Receive
FIFOs provide large on-chip storage space for both transmitted and received
frames. The 82558 chip provides full support for both half duplex and full duplex
operation, as well as support for full duplex flow control.

11
PC Package
PC Package
Front View
12.7 mm Slim CD-ROM Drive
Power Button
Power LED
Hard Disk Drive Access LED
LAN Active LED
Floppy Disk Drive (some models)
Rear Panel Screw
Rear View
Adapter Panel
Microphone Jack
Line-In Jack
Line-Out Jack
USB Ports
RJ45 LAN Connector
Parallel Port
Keyboard Connector
Mouse Connector
Serial Port 2
Serial Port 1
VGA Port
Rear Panel Screws
Power Supply Fan
Power Supply Connector
Rear Panel Screw
Top View
Power Supply Unit
System Board
Back of PC
Front Panel Chassis
Front of PC
Voltage Selection Switch

12
System Board and Backplane
System Board and Backplane
System Board
Backplane
PCI Slot
PCI Slot
ISA Slot
PCI/ISA
Combination
Slot
Connector is
on this side
Note: The HP Net
PC 20 does not
have an ISA slot.

13
System Board and Backplane
System Board Jumpers
CMOS Clear:
CMOS_CLR
This jumper allows you to enable or disable the CMOS clear feature.
CAUTION: DO NOT boot the system with the jumper in the CLEAR position.
Flash ROM Type Select:
EP1, EP2
These two jumpers allow you to configure the flash ROM chip.
Processor Speed This jumper lets you set the processor speed.
Function CMOS_CLR
Normal (default)
Clear
2 MB Flash ROM EP1 EP2
ATMEL AT29C020
SST 29EE020
AMD 28F020
INTEL 28F002
MXIC 28F2000
CPU Speed
(Core) Pin Number
7-8 5-6 3-4 1-2
233 ON ON OFF OFF
266 ON OFF ON ON
300 ON OFF ON OFF
333 ON OFF OFF ON
366 ON OFF OFF OFF
400OFFONONON

14
Removing and Replacing the Cover
Removing and Replacing the Cover
WARNING: For your safety, never remove the PC’s cover without first removing the power
cord from the power outlet, and any connection to a telecommunications
network. Always replace the cover before switching on the PC again.
Removing the Cover 1Switch off the display and the PC.
2Disconnect all power cords and any telecommunications cables.
3If the PC is being used in its vertical position, remove it from its base and place
it on a flat and stable surface.
4Using a screwdriver, loosen the three screws securing the chassis cover.
5Standing at the back of the PC, grasp the cover with both hands. Slide the
cover towards you and pull upwards until it slides off the main chassis.
To unclip the cover completely from the chassis, you may need to gently ease
the sides of the cover away from the chassis.
Base
Gently pull the sides of the
cover away from the chassis

15
Removing and Replacing the Cover
Replacing the Cover 1Standing at the back of the PC, lower the cover onto the chassis and slide the
cover forwards into position.
In order to clear the chassis as you slide the cover downwards onto the PC,
you may need to gently ease the sides of the cover outwards.
As you slide the cover forwards into position, make sure that the clips on the
inside of the cover engage properly with the top of the front panel chassis and
the sides of the main chassis.
2Using a screwdriver, tighten the three screws to secure the cover in position.
3If the PC is going to be used in its vertical position, stand it up and place it on
its base.
As you slide the cover into
position, press the sides
inwards slightly to help the
clips to engage

16
Removing the Front Panel Chassis
Removing the Front Panel Chassis
To gain full access to the system board you need to remove the front panel
chassis.
Removing the Front
Panel Chassis
1Remove the PC’s cover as described in “Removing the Cover” on page 14.
2Using a screwdriver, remove the two screws holding the front panel chassis in
place.
3Disconnect any cables that run between the front panel chassis and the system
board, for example, the hard disk drive data and power cables.
4Slide the front panel chassis away from the PC and place the chassis slightly in
front of the PC. If you have not disconnected the cables from the system board,
take care not to put any strain on the cables as you slide the front panel chassis
clear of the PC.

17
Removing the Front Panel Chassis
Replacing the Front
Panel Chassis
1Push the front panel chassis slightly into the main chassis.
CAUTION: Take great care with the cables, especially the hard disk drive data cable, when
you slide the front panel chassis into the main chassis.
2Reconnect any cables running between the front panel chassis and the system
board.
3Make sure that the front panel chassis is as far into the main PC chassis as it
will go, and then secure the front panel chassis in position.

18
Installing a Hard Disk Drive
Installing a Hard Disk Drive
To install a hard disk drive, take the following steps.
1Remove the cover (refer to “Removing the Cover” on page 14).
2Remove the front panel chassis (refer to “Removing the Front Panel Chassis”
on page 16).
3Slide the new hard disk drive on to the hard disk drive shelf and, using the four
screws supplied with the drive, secure the drive in position.
4Connect the IDE cable and the power supply cable to the hard disk drive.
5Place the front panel chassis slightly in front of the main chassis.
6Connect the other end of the IDE cable to the PRIMARY connector on the
system board (refer to “System Board and Backplane” on page 12).
7Connect the power cable coming from the back of the hard disk drive to the
HDD_PW connector on the system board (refer to “System Board and
Backplane” on page 12).
8Replace the front panel chassis (refer to “Replacing the Front Panel Chassis”
on page 17).
9Replace the cover (refer to “Replacing the Cover” on page 15).
Red edge Pin 1
Hard disk drive

19
Installing a Slim CD-ROM Drive
Installing a Slim CD-ROM Drive
To install a Slim CD-ROM drive, take the following steps.
1Remove the cover (refer to “Removing the Cover” on page 14).
2Remove the front panel chassis (refer to “Removing the Front Panel Chassis”
on page 16).
3Attach the L-shaped metal bracket by matching the two screw holes of the
metal bracket with the first and last screw holes of the group of four screw
holes on the right underside portion of the CD-ROM drive and securing the two
screws to it.
4If this is the first time that a CD-ROM is being installed in the PC, remove the
front panel plastic cover from the CD-ROM drive bay by pushing outwards
from the inside with your fingers.
5Slide the new CD-ROM drive onto the CD-ROM drive shelf and, using the
screws provided with the drive, secure the drive in position.
6Attach the CD-ROM drive adaptor to the CD-ROM drive adaptor connector
located at the back of the CD-ROM drive by:
afirst securing the copper hexagonal bolt to the rear of the CD-ROM drive by
hand, and
bsecuring the two mini-screws from the CD-ROM drive adaptor into the cop-
per hexagonal bolt with a mini-screwdriver.
First and last screw hole on the right
underside portion of the CD-ROM drive
L-shaped metal
bracket

20
Installing a Slim CD-ROM Drive
7Connect one end of the CD-ROM drive cable onto the CD-ROM drive.
8Place the front panel chassis slightly in front of the main chassis.
9Connect the other end of the CD-ROM drive cable to the CD_ROM connector
on the system board (refer to “System Board and Backplane” on page 12).
10 Replace the front panel chassis (refer to “Replacing the Front Panel Chassis”
on page 17).
11 Replace the cover (refer to “Replacing the Cover” on page 15).
Red edge
Pin 1