PROJECT EDITOR VICE PRESIDENT AND PUBLISHER
Linda Morris Andy Cummings
ACQUISITIONS EDITOR MEDIA DEVELOPMENT SUPERVISOR
Melody Layne Richard Graves
SR. COPY EDITOR MEDIA DEVELOPMENT SPECIALIST
Teresa Artman Kit Malone
TECHNICAL EDITOR SR. PERMISSIONS EDITOR
Dan DiNicolo Carmen Krikorian
EDITORIAL MANAGER PROJECT COORDINATOR
Kevin Kirschner Bill Ramsey
EDITORIAL ASSISTANT GRAPHICS AND PRODUCTION
Amanda Foxworth SPECIALISTS
VICE PRESIDENT AND EXECUTIVE Sean Decker
GROUP PUBLISHER Heather Pope
Richard Swadley Rashell Smith
Mary C. Corder PROOFREADING AND INDEXING
About the Author
Ron Gilster has been operating, programming, and repairing computers for more
than 30 years, and networking them for more than 13 years. Ron has extensive
experience in training, teaching, and consulting in computer-related areas, having
spent more than 20 years as a college-level instructor in A+, CCNA, MCSE, MOUS,
and computer programming programs. His experience includes mainframes, mini
computers, and virtually every type of personal computer and operating system in
use. In addition to a wide range of positions that have included systems program-
ming supervisor, customer service manager, data processing manager, management
information systems director, and executive positions in major corporations, Ron
has served as a management consultant with both an international accounting firm
and his own consulting firm.
He is the author of A+ Certification For Dummies, Network+ Certification For
Dummies, Server+ Certification For Dummies, i-Net+ Certification For Dummies,
CCNA For Dummies, Cisco Networking For Dummies, CCDA For Dummies, and
with Curt Simmons, MCSA All-in-One Desk Reference For Dummies, plus several
books on computer and information literacy and programming.
To my very best fan, friend, and wife — Connie.
If you’ve purchased or are considering the purchase of this book, you probably fit
into one of the following categories:
x You’re an experienced PC technician who wants a concise reference on
PCs and how to troubleshoot and repair them.
x You think that reading this book might be a fun, entertaining way to
extend your knowledge of PCs and their components.
x You either have or are preparing for A+ certification.
x You’re a big fan of mine and can hardly wait for my next book.
If you fit into one or more of these descriptions (except the last one, for which I am
not qualified in the appropriate medical areas to help you), this is the book for you!
About This Book
If your goal is to discover more about PCs, their components, and how to identify
and fix their problems, you’re in the right place. In this book, I provide you with
some background information on the major component areas of a personal com-
puter and also offer detailed procedures that you can use to resolve many of the
common failures and problems that can occur on a user’s PC.
I fondly remember the days when I could lift the hood (bonnet for my British
readers) on my car and not only identify all the parts but also actually repair or
replace a broken or malfunctioning component. Sadly, those days are gone, and I
must now depend on Mr./Ms. Goodwrench to fix anything under the hood of my
car. Luckily, this evolution has not quite transpired on PCs . . . at least not yet. If
anything, the components under the hood of the PC have gotten simpler to identify,
and problems that occur are getting easier to isolate and resolve.
However, typical users, although growing more and more savvy with software,
are reluctant to fix their PCs themselves, preferring to call on Mr./Ms. Gooddriver to
fix their PC hardware when something goes wrong. And because not every PC tech-
nician can know every problem and the right or best procedure to use when finding
and fixing a PC problem, I wrote this book as a guide.
In writing this book, I’ve made the assumption that you are a PC technician with
at least a few months of hands-on experience in the installation, configuration, and
repair of PCs as well as a fundamental knowledge of electronics, computers, soft-
ware, protocols, and troubleshooting procedures. If you’re just getting started,
though, don’t worry that this book makes too many assumptions concerning your
knowledge, experience, and abilities. On the contrary, I’ve tried to present things in
such a way that whether you’re just getting started or have years of experience, the
information, processes, and procedures that I’ve included are useful.
How to Use This Book
Like with the majority of my other books on PC hardware topics, this book is
intended as a reference and troubleshooting guide that you can keep handy on your
workbench — hence, the Bench Book part of the title. Each major component group
is presented first with some general background information to orient you to its
operation, compatibilities, and common problems.
This book presents the facts, concepts, processes, and applications that a PC
technician needs to know in step-by-step lists, tables, figures, and text without
long or (hopefully) boring explanations. The focus is to provide you with informa-
tion on the how’s and why’s of PC hardware components and not to impress you
with my obviously extensive and impressive knowledge of PCs (nor my modesty, I
Another excellent reference tool that you can use, especially if you’re just get-
ting started, is A+ Certification For Dummies, 2nd Edition (Wiley Publishing, Inc.).
Okay, so this is a shameless plug of another of my books, but it’s still a good refer-
ence on PCs.
Appendix A includes a list of my favorite PC hardware reference books.
How This Book Is Organized
This book is organized to allow you to find information specific to certain hardware
or component groups without the need to wade through stuff you already know. At
the beginning of each chapter is a list of topics that you can use as a guide to
what’s in the chapter.
You’ll also find that some topics might be covered in more that one place in the
book, with one location providing more information than the other. Some informa-
tion has a better relationship to certain other areas and is placed into the context of
a specific or related issue. Rely on the index of the book to find the specific page
where a certain topic, component, or issue is covered. I’ve also included cross refer-
ences to other information that you might find useful.
Here are the parts of the book and what they cover.
Part I: The Motherboard and Its Components
This book is organized around the major component areas of a personal computer.
Part I begins at the heart of the PC, covering the motherboard, processor, chipset,
Basic Input/Output System (BIOS), system resources, memory, and cache memory.
Although these components aren’t typically the source of a PC problem, it’s a good
idea that you know and understand their function, fit, and processes in relationship
to the other parts of the PC.
Part II: The System Case and Power Supply
The PC’s case and power supply are responsible for more PC problems than most
people think. I’ve put them together because they typically come as a combined
part and to emphasize their importance to the PC’s overall operations.
Part III: Storage Devices
Unfortunately, this part of the book doesn’t provide you with a better way to
explain to a user the difference between memory and permanent data storage
devices; you’re still on your own with that. What this part does provide is an in-
depth look into the more common data storage devices, such as hard disks, floppy
disks, CD-ROMs, and the like. The information included in this part covers the con-
struction, operation, and common issues of data storage devices, which are now an
essential part of any PC.
Part IV: Sight and Sound Systems
PCs are designed to provide an interactive processing environment. A user’s basic
interactive tools are his or her eyes and ears. (Touch, smell, and mental telephony
can’t be too far off.) The PC’s display and sound systems provide the basis for the
interaction between the user and the PC. When one of these component groups has
a problem, it’s typically a BIG problem for the user.
This part of the book deals with the PC’s video and display systems and the com-
ponents of its sound system.
Part V: Printers
If a broken monitor or a quiet sound system causes grief for the user, a broken
printer is a major catastrophe. Because of the importance of printers, this part of the
book focuses solely on PC printers, their operations, issues, and how to get them
back up and running.
Part VI: Keyboards and Pointing Devices
Although speech recognition systems that actually work are on the horizon, the
user’s main tool for entering data and commands to the PC are still the keyboard
and mouse. Because several types of both devices are on the market, when you’re
presented with a problem in either, you need to know which device type you’re
working with and what’s the best way to fix it.
In addition, this part of the book also looks at other devices used to enter or
manipulate data on the PC, such as joysticks, digital tablets, and the like.
Part VII: Communications and Networking
Without including so much information on data communications and network that
this book turns into a networking bench book, this part looks at the components
and processes used to connect a PC to a local area network (LAN).
Part VIII: Configuring the PC
Most of the configuration tasks on a PC surround the configuration of expansion
cards and the ports and connectors through which external peripheral devices are
attached to the PC. This part covers the types, compatibilities, installation, and con-
figuration of expansion cards and the PC’s external ports and connectors.
Part IX: PC Operating Systems
Have no fear; this part of the book doesn’t cover application software or how to
create a really nifty document or Web site. What it does cover is the Windows and
Linux operating systems and their installation, configuration, and troubleshooting.
Installing a new PC often includes either the installation and configuration or the
upgrading of an operating system. This part of the book provides information on
the more popular Windows operating system versions and a look into the world of
Part X: Maintaining a PC
The two major parts of PC maintenance are preventive care and optimization,
which coincidently are the two chapters in this part. A well-maintained PC has a
much better chance for an extended life, and the procedures used to perform an
organized and regularly applied preventive maintenance plan are covered. And
because you’ll occasionally want to try to get just a little better performance out of
a PC, here I offer some system optimization techniques. Although it flies in the face
of the philosophy that If it isn’t broke, don’t fix it, this might be the part of the book
that you refer to the most (or at least you should).
Part XI: Appendix
The appendix gives a complete listing of third-party software and bonus content on
the CD-ROM that accompanies this book. Highlights are three bonus appendixes
(troubleshooting tips, suggesting software and hardware tools, and a complete glos-
sary), as well as a searchable PDF of the entire text of this book.
Icons Used in This Book
Look to Cross Reference icons to find additional or expanded information
on a particular topic.
Note icons provide more information to help you understand a particular
point or to make some information more relevant.
Tip icons flag information that can come in extra-handy while working
on a PC.
The Caution icon alerts you to some potentially dangerous or treacherous
material. Heads up!
Where to Go from Here
Only you know where you need to begin reading this book. If you need more infor-
mation on motherboards and their components, start with Part I. If you need some
advice on working with video or sound on a PC, start with Part IV. There is no right
or wrong place to begin working with this book.
Talk to Me
I’d like to hear from you. If any aspect or topic of PC repair isn’t covered as well as it
should be, or if I’ve provided more coverage than you think is warranted about a par-
ticular topic, please let me know. Or if I’ve made an error or misstated a fact (it could
happen!), I’d appreciate hearing about it. Your feedback is solicited and welcome. You
can send e-mail to me at this e-mail address: email@example.com.
I’d like to acknowledge the contributions of a virtual cast of tens who helped this
project along. This includes the very excellent crew from Wiley Publishing, Inc.,
without whom this book would look like my desktop (not a pretty sight, I might
add): Melody Layne, Linda Morris, Teresa Artman, Kim Darosett, and Amanda
Foxworth. A special thanks goes to Rashell Smith and David Bartholomew who did
such a wonderful jobe illustrating this book. I would also like to extend a huge
thanks to Dan DiNicolo for challenging me with his absolutely great technical
I’d also like to thank the manufacturers, vendors, and suppliers of PC hardware
and software that provided photographs and illustrations for the book.
And last, but certainly not least, I’d like to acknowledge the support of my family
(Connie, Markus, Jessica, and Carly) and my dear friend and agent (Margot Maley
Hutchison), without whom I couldn’t have survived this task.
The Motherboard and
Mastering the Motherboard
Chipsets and Controllers
Booting and the BIOS
Configuring System Resources
Applying Cache Memory
IN THIS CHAPTER
The motherboard, also known as the system board, main board, or planar board, is
a large printed circuit board that includes or provides an interconnect to most of
the essential components of the PC:
x Microprocessor (see Chapter 2)
x Expansion bus (see Chapter 2)
x Chipset (see Chapter 3)
x Memory sockets and RAM modules (see Chapter 6)
x Cache memory (see Chapter 7)
x Integrated Drive Electronics (IDE), Enhanced IDE (EIDE), or Small
Computer System Interface (SCSI) controllers (see Chapter 11)
x Mouse and keyboard connectors (see Part VI)
x Parallel and serial ports (see Parts V and VI)
AS THIS LIST SHOWS, there is more to working with a motherboard than I can cover
in just this one chapter. Motherboards are the glue that binds the PC’s components
together. I can safely say that virtually every component, internal or peripheral,
that’s installed on or connected to a PC has some connection (no pun intended!) to
Motherboard manufacturers attempt to differentiate their products and increase
their value by integrating a varying combination of devices and controllers into
their boards. The upside of including more on the motherboard is a wider compati-
bility to a wider range of systems and potentially a deeper list of features. The
downside is that unless you’re very careful when selecting a new motherboard, you
might not get the combination or quality of processor or peripheral support that
Although I assume that you have some background in working with PCs and their
components, I want to be sure that you and I are on the same page when it comes to
motherboards. In the following sections, I cover what is likely some fundamental
material. However, when it comes to motherboards, I’d rather be safe than sorry. 3
4 Part I: The Motherboard and Its Components
Differentiating Motherboard Designs
If PCs had only a single type and style of motherboards, the task of working with
them would be greatly simplified. However, even though most of today’s PCs use
the ATX (see “Creating the new standard: The ATX” later in this chapter), you can
expect to encounter different motherboard form factors on the job. If, after all else
has failed, you decide to replace a PC’s motherboard, you must match the form fac-
tor of the motherboard to the case and its mountings.
Laying out the mainboard
Essentially, the two basic design approaches to PC motherboards are the mainboard
(or the true mother-of-all-boards) design and the backplane design.
A mainboard design, like the one in Figure 1-1, incorporates the PC’s primary
system components on a single circuit board. This type of motherboard contains
most of the circuitry of a PC and acts as the conduit through which all the PC’s
On a typical motherboard (see Figure 1-1), you will find the microprocessor, the
Basic Input/Output System (BIOS) ROM, the chipset, RAM, expansion cards, per-
haps some serial and parallel ports, disk controllers, connectors for the mouse and
the keyboard, and possibly a few other components as well.
Mainboard motherboard designs, although somewhat standard, do vary in
the inclusion and placement of system components and interfaces. Before
you charge down the road to diagnose, troubleshoot, or replace any
motherboard, be very sure that you can at least identify the components
indicated in Figure 1-1 on your PC’s mainboard.
Connecting to the backplane
There are actually two types of backplane mainboards: passive and active. A pas-
sive backplane mainboard is only a receiver card with open slots into which a
processor card (which contains a central processing unit [CPU] and its support
chips) and input/output (I/O) cards that provide bus and device interfaces are
plugged. These add-in cards are referred to as daughterboards.
The backplane interconnects the system components through a bus structure and
provides some basic data buffering services. The backplane design is popular with
server-type computers because it can be quickly upgraded or repaired. The back-
plane design provides the advantage of getting a server back online with only the
replacement of a single slotted card, instead of replacing an entire mainboard!
Chapter 1: Mastering the Motherboard 5
PCI slots BIOS ROM I/O ports CPU socket
Chipset IDE ports CMOS battery
Figure 1-1: The essential (and most common) mainboard components.
Photo Courtesy of AOpen, Inc.
An active backplane design, also called an intelligent backplane, adds some CPU
or controller-driven circuitry to the backplane board, which can speed up the pro-
cessing speed of the system. Even on an active backplane, the CPU is on its own
card to provide for easy replacement.
The utility of the backplane design is being challenged by newer motherboards
that incorporate the slot-style mountings of Pentium-class processors. The advan-
tage of the active backplane is that the processor can be easily accessed and
replaced, but the slot-style motherboards also offer this same advantage.
For purposes of clarity and because they are the most commonly used in
PCs, when I refer to a motherboard, I am referring to the mainboard design.
When referring to a backplane design, I will specifically say so.
6 Part I: The Motherboard and Its Components
Factoring in the motherboard form
When the original IBM PC was introduced in 1981, it had a simple motherboard
designed to hold an 8-bit processor (the Intel 8088), five expansion cards, a key-
board connector, 64–256K RAM (from individual memory chips mounted on the
motherboard), a chipset, BIOS ROM, and a cassette tape I/O adapter for permanent
storage. The PC was designed to be a desktop computer, and its system case layout
dictated the first of what are now called motherboard form factors. Simply, a form
factor defines a motherboard’s size, shape, and how it is mounted to the case.
However, form factors have been extended over time to include the system case, the
placement and size of the power supply, the power requirements of the system,
external connector placements and specifications, and case airflow and cooling
Table 1-1 lists the common form factors that have been and are being used in PCs.
TABLE 1-1 MOTHERBOARD FORM FACTORS
Style (inches) (inches) Design Case Type
IBM PC 8.5 13 Mainboard IBM PC
IBM PC XT 8.5 13 Mainboard IBM PC XT
IBM PC AT 12 11–13 Mainboard Desktop or tower
Baby AT 8.5 10–13 Mainboard Desktop or tower
LPX 9 11–13 Backplane Desktop
Micro-AT 8.5 8.5 Mainboard Desktop or tower
ATX 12 9.6 Mainboard Desktop or tower
Mini-ATX 11.2 8.2 Mainboard Desktop
Mini-LPX 8–9 10–11 Backplane Desktop
Micro-ATX 9.6 9.6 Mainboard Desktop
NLX 8–9 10–13.6 Backplane Desktop
Flex-ATX 9 7.5 Mainboard Desktop or tower
SETTING THE STANDARD: THE IBM AT
When IBM released its first 16-bit computer, the PC AT, the circuitry added to the
motherboard of its predecessor (the PC XT) increased the size of its motherboard
and case to 12 inches wide by 13 inches deep. During this time, many clone
Chapter 1: Mastering the Motherboard 7
(non-IBM) manufacturers also began releasing XT-compatible motherboards, which
included keyboard connectors, expansion slots, and mounting holes to fit into AT
cases. The AT’s size, shape, and mounting placements became the first motherboard
form factor standard, a standard that has essentially continued through today.
Nearly all present-day motherboard form factors are a derivative of the early AT
BRINGING UP THE BABY AT
It wasn’t long before clone manufacturers began releasing their own 16-bit PCs and
motherboards with higher integration in the supporting chipsets that allowed their
motherboard to take a smaller form. This smaller form was called the Baby AT,
shown in Figure 1-2, a more compact motherboard that was compatible with AT
cases. The Baby AT became very popular because of its size and flexibility and
joined the AT motherboard as a de facto standard.
Figure 1-2: A Baby AT motherboard.