Repairing and Upgrading Your PC

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

If you find the thought of doing your own repairs or upgrades to your PC a bit intimidating, you're not alone. Nearly everyone feels that way at the beginning, but there's really nothing to worry about. Working on a PC is no more technically challenging than changing the oil in your car or hooking up a DVD player. Compared to assembling one of those "connect Tab A to Slot B" toys for your kids, it's a breeze.

PC components connect like building blocks. Component sizes, screw threads, mounting hole positions, cable connectors, and so on are standardized, so you needn't worry about whether something will fit. There are minor exceptions, of course. For example, some small cases accept only half-height or half-length expansion cards. There are important details, certainly. If you're upgrading your processor, for example, you must verify that your current motherboard supports the new processor. But overall there are few "gotchas" involved in repairing or upgrading a PC.

Nor do you need to worry much about damaging the PC—or it damaging you. Taking simple precautions such as grounding yourself before touching static-sensitive components and verifying cable connections before you apply power are sufficient to prevent damage. Other than inside the power supply or CRT monitor—which you should never open—the highest voltage used inside a modern PC is 12V, which presents no shock hazard.

If you've never taken the cover off your PC before, you'll probably be amazed at how empty it is inside. Spend a few minutes comparing the photographs in this book to what you see inside the case, and you'll soon be able to identify all the important parts and what they do. From there, it's only a small step to repairing or upgrading your system by installing new parts to replace the old. Sooner than you think, you'll be an expert.

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

With entry-level PCs selling for less than $500 and fully equipped mainstream PCs selling for $1,200, you might wonder if it's even worthwhile to repair or upgrade your old system. After all, a new system comes with a warranty, all new software, and shiny new parts. The problem is—and we'll try to put this politely—a cheap new system is just that. Cheap. Year after year, consumer-grade, mass-market PCs are cost-reduced more and more. That shiny new cheap system comes with a cheap, unreliable motherboard; a small, slow hard drive; barely adequate memory; a marginal power supply; and so on. TANSTAAFL: There Ain't No Such Thing As A Free Lunch.

Is it impossible, then, to buy a good system, manufactured with high-quality components? Of course not, but don't expect to get it at a bargain price. Business-grade systems from name-brand vendors and systems targeted at gamers and other enthusiasts use high-quality components, but those systems are priced 50% to 200% higher than consumer-grade, mass-market systems. If you compare apples to apples, you'll often find that it's cheaper overall to repair or upgrade your current system than to buy an equivalent new system.

There are other good reasons to repair or upgrade your PC rather than replace it:

More choice: When you buy a PC, you get a cookie-cutter computer. You can choose such options as a larger hard drive, more memory, or a better monitor, but basically you get what the vendor decides to give you. If you want something that few people ask for, like a better power supply or quieter cooling fans or a motherboard with more features, you're out of luck. Those options aren't available.

And what you get is a matter of chance. High-volume direct vendors like Gateway and Dell often use multiple sources for components. Two supposedly identical systems ordered the same day might contain significantly different components, including such important variations as different motherboards or monitors with the same model number but made by different manufacturers. When you upgrade your PC yourself, you decide exactly what goes into it.

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

The most popular upgrades fall into one or more of the following categories:

Feature upgrades add capabilities to your PC, such as DVD burning, video capture, or wireless networking.
Reliability upgrades are targeted at reducing the likelihood, frequency, and severity of hardware failures.
Performance upgrades speed up your system.
Quiet upgrades reduce the noise level of your system.
Convenience upgrades make it easier to do things you want to do.
Data safety upgrades reduce the likelihood that your bdata will be corrupted or lost.

Table 1-1 lists the 20 most popular PC upgrades by type, cost, and difficulty, ordered from least to most expensive. The actual cost of an upgrade obviously varies by the specific component you choose, but we've provided approximate ranges, as follows:

$:	$0 to $50
$$:	$50 to $125
$$$:	$125 to $250
$$$$:	$250+

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

As much as we would like to recommend specific components by brand name and model number in this book, those recommendations would be outdated soon after the book was printed. To avoid this timeliness problem, we maintain online forums where you can always read about our current recommendations (and those of our expert forum members). Before you buy components to repair or upgrade your system, visit our forums at:

http://forums.hardwareguys.com

It's best to search before you ask on the forums. The same questions are often asked (and answered) repeatedly, so please spend a few minutes browsing and searching the forums before you post a question. Chances are good that the search engine will locate an existing answer to your specific question among the thousands of posts. If not, post your question, but make sure to give as as much specific information as possible. The more pertinent information you provide with your question, the more likely the answers are to be fast, complete, and accurate.

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

Until the early 1990s, most computer products were bought in computer specialty stores. Retail sales still make up a significant chunk of computer product sales—although the emphasis has shifted from computer specialty stores to local "big-box" retailers like Best Buy, CompUSA, Fry's, Wal-Mart, and Costco—but online resellers now account for a large percentage of PC component sales.

Should you buy from a local brick-and-mortar retailer or an online reseller? We do both, because each has advantages and disadvantages.

Local retailers offer the inestimable advantage of instant gratification. Unless you're more patient than we are, when you want something, you want it right now. Buying from a local retailer puts the product in your hands instantly, instead of making you wait for FedEx to show up. You can also examine the product in person before purchase, something that's not possible if you buy from an online reseller. Local retailers also offer a big advantage if you need to return or exchange a product. If something doesn't work right, or if you simply change your mind, you can just drive back to the store rather than dealing with the hassles and cost of returning a product to an online reseller.

Online resellers have the advantage in breadth and depth of product selection. If you want the less-expensive OEM version of a product, for example, chances are that you won't find it at local retailers, most of which stock only retail-boxed products. If an online reseller stocks a particular manufacturer's products, it tends to stock the entire product line, whereas local retailers often pick and choose only the most popular items in a product line. Of course, the popular products are usually popular for good reasons. Online resellers are also more likely to stock niche products and products from smaller manufacturers. Sometimes, if you must have a particular product, the only option is to buy it online.

Online resellers usually advertise lower prices than local retailers, but it's a mistake to compare only nominal prices. When you buy from a local retailer, you pay only the advertised price plus any applicable sales tax. When you buy from an online retailer, you pay the advertised price plus shipping, which could end up costing you more than buying locally.

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

Your first PC repair or upgrade can be pretty intimidating. What if it doesn't work? Worse still, what if the PC goes up in flames the first time you turn it on? Set your mind at ease. This isn't rocket surgery. Any reasonably intelligent person can repair or upgrade a PC with a high degree of confidence that it will work normally afterward. If you use good components and work carefully, everything usually just works.

Still, stuff happens. So, although we provide more detailed troubleshooting suggestions for specific components throughout this book, we thought it was a good idea to summarize early in the book some basic troubleshooting steps to cover the most common problems that occur during a system repair or upgrade.

Possible problems fall into one of four categories, easy versus hard to troubleshoot and likely versus unlikely. Always check the easy/likely problems first. Otherwise, you may find yourself tearing down the system again before you notice that the power cord isn't plugged in. After you exhaust the easy/likely possibilities, check the easy/unlikely ones followed by hard/ likely and, finally, hard/unlikely.

Most problems that occur during repairs and system upgrades result from one or more of the following:

Cable problems: Disconnected, misconnected, and defective cables cause more problems than anything else. The plethora of cables inside a PC makes it very easy to overlook a disconnected data cable or to forget to connect power to a drive. It's possible to connect some cables backward. Ribbon cables are a particularly common problem, because some can be appear connected, yet be offset by a row or column of pins. And the cables themselves cannot always be trusted, even if they are new. If you have a problem that seems inexplicable, always suspect a cable problem first.

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

Popping the lid of a PC for the first time can be pretty intimidating, but there's really no need for concern. There's nothing inside that will hurt you, other than sharp edges and those devilish solder points (fortunately much reduced in recent years with increased surface mounting of electrical components). There's also nothing inside that you're likely to damage, assuming that you take the few simple precautions detailed in this chapter.

Some PCs—particularly those from big-box stores—have seals that warn you that the warranty is void if they're broken. This isn't so much to protect them against your ham-handedness as it is to ensure that you have to come back to them and pay their price for upgrades. We advise people to break such seals if they need to, do their own upgrades, and fight it out later if they have a problem that should be covered under warranty.

We've never heard of anyone being refused warranty service because of a broken seal, but there's always a first time. If you have a sealed PC that is still under warranty, the decision is yours. Note that some individual components inside, such as hard disks, are a special case. Breaking the seal on a hard disk does actually destroy it and will without question void the warranty. And, unless you are qualified to do so, don't ever open up a power supply or CRT monitor. Dangerous voltages await you inside.

Those issues aside, feel free to open your PC and tinker with it as you see fit. Far from forbidding you to work on your own PC, most online computer vendors actually expect you to do your own upgrades and repairs. As a matter of fact, most of them will try very hard to talk you into doing your own warranty repairs so that they can avoid sending a technician to do them for you. The rest of this chapter explains the fundamentals you need to understand to start upgrading and repairing your PC.

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

We've upgraded and repaired hundreds of systems over the years, and learned a lot of lessons the hard way. Here are the rules we live by. We'll admit that we don't always take each of these steps when we're doing something simple like swapping a video card, but you won't go far wrong if you follow them until you have enough experience to know when it's safe to depart from them.

Back everything up.: Twice. Do a verify pass, if necessary, to make sure that what is on the backup matches what is on the hard drive. Better still, do at least a partial restore to a scratch directory to make sure that your backups are readable. If you're connected to a network, copy at least your data and configuration files to a network drive. If there's room on the network drive, create a temporary folder and copy the entire contents of the hard disk of the machine about to undergo surgery. If you don't have a network but you do have a CD or DVD writer, back up at least your important data and configuration files to optical discs. About 99 times in 100, all of this will be wasted effort. The hundredth time—when everything that can go wrong does go wrong—will pay you back in spades for the other 99. Be sure to check out Chapter 3, which discusses backups and other preventative maintenance in detail.
Make sure you have everything you need before you start.: Have all of the hardware, software, and tools you'll need lined up and waiting. You don't want to have to stop mid-upgrade to go off in search of a small Phillips screwdriver or to drive to the store to buy a cable. If your system can boot from the optical drive, configure it to do that and test it before proceeding. Otherwise, make sure that you have a boot disk with drivers for your optical drive, and test it before you start tearing things down. Create a new emergency repair disk immediately before you start the upgrade. Make certain that you have the distribution discs for the operating system, service packs, backup software, and any special drivers you need. If you're tearing down your only PC, download any drivers you will need and copy the unzipped or executable versions to floppies or burn them to CD

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

Despite those snazzy-looking PC toolkits you see anywhere PC components are sold, you really don't need much in the way of tools to work on a standard PC. Figure 2-2 shows our standard toolkit—a #1 Phillips screwdriver, flashlight, and needlenose pliers—and we seldom need the pliers.

Figure 2-2: A basic toolkit: #1 Phillips screwdriver, flashlight, and needlenose pliers

A bottle or pen of Wite-Out and a Sharpie marker can be useful for labeling items. Depending on your system, you may also need a #0 or #2 Phillips screwdriver, although the #1 Phillips generally works fine for the screw heads used in standard PCs. If your system uses Torx fasteners, you may need a #10, #15, or #20 Torx screwdriver. There are other tools that are convenient rather than essential. If you're replacing a motherboard, for example, a 5 mm or 6 mm nut driver makes it faster to install the standoffs, and a screw starter makes it easier to insert screws in inaccessible places. But you can get along just fine with only a screwdriver or two, a flashlight, and needlenose pliers for setting jumpers. You needn't buy special "computer" tools, either.

Regular tools from the hardware store, Sears, or a home improvement center work just fine.

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

In addition to basic hand tools, you may need some software tools to diagnose and troubleshoot problems and to recover from them. The conundrum, of course, is that most diagnostic software utilities run under Windows, but quite often when you're troubleshooting it's because Windows won't load or run because it's corrupted itself or been damaged by a virus or worm.

Fortunately, there's an alternative. A "Live Linux CD" such as Knoppix (http://www.knoppix.org), shown in Figure 2-3, allows you to boot and run a full-featured Linux operating system directly from the CD, without altering the contents of your hard drive. Knoppix and similar Live CD distributions include a plethora of graphics-based tools that allow you to diagnose, test, and burn-in the various hardware components of your system.

Figure 2-3: The Knoppix desktop

Knoppix is priceless when you need to recover data from a corrupted or otherwise inaccessible hard drive that Windows won't touch. Figure 2-3, for example, shows Knoppix running on a system that had crapped out under Windows. Windows refused to boot, and we didn't want to risk a reinstall before we salvaged the data on the drive.

Knoppix gave us read-only access to the Windows partition, and allowed us to browse it and copy the data files to a safe location. Knoppix even recognized the Windows network we were connected to, and allowed us to save the recovered files to a shared Windows volume on another machine on the network. If the machine hadn't been connected to a network, we could have used K3b (a Linux CD/DVD burning application) to write the recovered files to a CD or DVD—all of this simply by pointing and clicking, just like Windows. You don't need to learn Linux to use Knoppix.

We don't have room here to detail all of the many capabilities of Knoppix. Download a copy for yourself (now, before you need it) and play around with it. Search Google for "Knoppix recover" or "Knoppix rescue" and you'll find dozens of documents that explain the hardware analysis, testing, and data recovery features of Knoppix. Oh, did we mention that Knoppix is free for the download? Knoppix is also available on CD for a nominal fee from online vendors like CheapBytes (

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

With the hand tools and utilities described in the preceding sections, you have everything you need to upgrade or repair a PC except for the new components. Before you start, take a few minutes to read through the following sections, which describe the common procedures and general knowledge you need to work on PCs. These sections describe the common tasks involved in working on a PC—things like opening the case, setting jumpers, manipulating cables, and adding or removing expansion cards. Instructions for specific tasks like replacing a motherboard, disk drive, or power supply are given in the relevant chapter.

The best way we've found to organize and protect CDs and DVDs is to lose the jewel cases and store them—or, better still, copies of them—in one of those zippered vinyl or Cordura disc wallets you can buy for a few dollars at Wal-Mart or Best Buy. These wallets use plastic or Tyvek sleeves to protect the discs, hold from half a dozen to several dozen discs, and make it easy to find the one you want. If the disc has a serial number or activation key on the original jewel case, make sure to record it on the CD, using a soft permanent marker on the label side. It's also a good idea to record the serial number or initialization (init) key on the disc sleeve or a small card so that the number is accessible when the disc is already in the drive.

We stock one of these wallets with essential discs—Windows and Linux distribution CDs, applications, various diagnostics, and so on—and always have it at hand. We also buy a disc wallet for each PC we buy or build. New PCs usually arrive with several discs, as do individual components. Storing these discs in one place, organized by the system they belong to, makes it much easier to locate the one you need.

Although you may be raring to get in there and fix something, taking the time to prepare properly before you jump in pays big dividends later. When your system has problems, do the following before you open the case:

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

Airlines, trucking companies, and other large organizations devote much more time, money, and effort to cleaning and preventative maintenance than they do to repairs. That's because cleaning and regular system maintenance repay their costs many times over by reducing the frequency and cost of repairs. It's almost always cheaper to prevent something from breaking than it is to fix it after it's broken. The same is true for PCs.

Dirt is the main enemy of PCs. Dirt blocks air flow, causing the system to run hotter and less reliably. Dirt acts as thermal insulation, causing components to overheat and thereby shortening their service lives. Dirt causes fans to run faster (and louder) as they attempt to keep the system cool. Dirt worms its way into connectors, increasing electrical resistance and reducing reliability. Dirt corrodes contact surfaces. Dirt is nasty stuff.

Computers become dirty as a natural part of running. Fans suck dust, pet hair, and other contaminants into the case, where they rest on every surface. Even in clean rooms, operating theaters, and other very clean environments, a PC will eventually become dirty. If there's any dust in the air at all, the system fans will suck it in and deposit it inside the case, where it will become a problem sooner or later.

The severity of the problem depends on the environment. Industrial environments are often filthy, so much so that standard PCs are unusable. In a shop-floor environment, we have seen standard PCs become so clogged with dirt—literally in one day—that they stopped running because of overheating. Typical home and office environments are much better, but still surprisingly bad. Pets, carpeting, cigarette smoking, gas or oil heat—all of these contribute to dirty PCs.

Routine weekly vacuuming of the case exterior helps, but is not sufficient. Figure 3-1 shows the back I/O panel of a PC that was left running 24 hours a day for 6 months in a typical residential environment—which happens to be our home—without being cleaned other than casual vacuuming of the accessible areas of the case. (Barbara asked Robert to point out that she vacuums thoroughly and dusts every week, but that Robert specifically asked her to make no special effort to clean this system so that he could use it as an illustration.)

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

Dirt is the main enemy of PCs. Dirt blocks air flow, causing the system to run hotter and less reliably. Dirt acts as thermal insulation, causing components to overheat and thereby shortening their service lives. Dirt causes fans to run faster (and louder) as they attempt to keep the system cool. Dirt worms its way into connectors, increasing electrical resistance and reducing reliability. Dirt corrodes contact surfaces. Dirt is nasty stuff.

Computers become dirty as a natural part of running. Fans suck dust, pet hair, and other contaminants into the case, where they rest on every surface. Even in clean rooms, operating theaters, and other very clean environments, a PC will eventually become dirty. If there's any dust in the air at all, the system fans will suck it in and deposit it inside the case, where it will become a problem sooner or later.

The severity of the problem depends on the environment. Industrial environments are often filthy, so much so that standard PCs are unusable. In a shop-floor environment, we have seen standard PCs become so clogged with dirt—literally in one day—that they stopped running because of overheating. Typical home and office environments are much better, but still surprisingly bad. Pets, carpeting, cigarette smoking, gas or oil heat—all of these contribute to dirty PCs.

Routine weekly vacuuming of the case exterior helps, but is not sufficient. Figure 3-1 shows the back I/O panel of a PC that was left running 24 hours a day for 6 months in a typical residential environment—which happens to be our home—without being cleaned other than casual vacuuming of the accessible areas of the case. (Barbara asked Robert to point out that she vacuums thoroughly and dusts every week, but that Robert specifically asked her to make no special effort to clean this system so that he could use it as an illustration.)

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

The best way to deal with problems is to stop them from happening in the first place. That's where preventative maintenance comes in.

A good preventative maintenance program incorporates a comprehensive backup plan, measures to secure the system against malicious exploits, periodic hardware and software maintenance, and steps to maintain general system tidiness. The goals of preventative maintenance are to reduce the likelihood of hardware failures, extend the useful life of the system, minimize system crashes caused by outdated drivers and other software problems, secure the system against viruses and other malware, and prevent data loss.

The following sections outline a basic preventative maintenance program that you can use as a basis for developing a program that fits your own and your system's needs.

Maintaining a good set of backups is a critical part of preventative maintenance.

The availability of inexpensive hard drives and motherboards that support RAID 1 mirroring had led many people to depend solely on RAID 1 to protect their data. That's a very bad idea. RAID 1 protects only against the failure of a hard drive, which is partial protection at best. RAID 1 does nothing to protect against:

Data being corrupted by viruses or hardware problems
Accidentally deleting, overwriting, or modifying important files
Catastrophic data loss, such as fire or theft of your equipment

To protect against those and other threats, the only reliable solution is to make backup copies of your data periodically to some form of removable media, such as tapes, optical discs, or removable hard drives.

Section 3.2.1.1: Backup hardware

In the past, there weren't any really good hardware choices for backing up home and SOHO systems. Tape drives were expensive, complex to install and configure, used fragile and expensive media, and were painfully slow. CD writers, although reasonably fast and inexpensive, stored such a small amount of data that many people who used them for backing up were reminded of the Bad Olde Days of swapping floppy disks. External hard drives were expensive and of dubious reliability.

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

The motherboard is Control Central for a computer. Every other component—processor, memory, drives, expansion cards, and even the power supply—connects to and is controlled by the motherboard. The motherboard defines the computer.

Replacing the motherboard is the most complicated and time-consuming upgrade you can make to a computer, simply because so many things connect to it. But there are many good reasons to replace a motherboard, including:

The original motherboard has failed.
You want additional features—such as Serial ATA, USB 2.0, FireWire, support for hard drives larger than 128 GB, or a PCI Express video slot—that your original motherboard does not provide.
You want to upgrade your processor, but the original motherboard does not support the type or speed of processor you want to install.
You want to install additional memory, but the type of memory used by your motherboard is no longer available or is very expensive.
Your motherboard is one of the millions made with defective capacitors, and so may fail without warning. Figure 4-1 shows a row of six healthy capacitors on an ASUS K8N-E Deluxe motherboard. If those on your motherboard appear swollen, popped, or are leaking fluid, that motherboard will soon fail.

Figure 4-1: Healthy capacitors show no signs of bulging or leakage

If your motherboard fails, there are no options but to replace it or discard the computer. If your goal is simply to repair the system as inexpensively as possible, you can probably find a suitable motherboard for $50 to $75 that will accept your current processor and memory, unless the system is elderly.

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

Two fundamental characteristics determine whether a motherboard is suitable for upgrading a particular system:

Form factor: The form factor of a motherboard defines its physical size, mounting hole locations, and other factors that determine whether the motherboard fits a particular case. The vast majority of computers made since 1995 use either the ATX form factor, also called full ATX, or the microATX form factor, also called μATX. A microATX motherboard fits a microATX case or an ATX case; an ATX motherboard fits only an ATX case. Figure 4-2 shows a typical microATX motherboard on the left, with a larger ATX motherboard on the right.

If your current case accepts ATX or microATX motherboards and has a compatible power supply, upgrading the motherboard is a simple matter of removing the old motherboard and replacing it with the new one. Alas, some systems—primarily cheap, mass-market units—use nonstandard proprietary motherboards and/or power supplies. If the motherboard in such a system fails, that system is good for little more than the scrap heap. You may be able to salvage the processor, memory, drives, and other peripherals, but the case and motherboard are useless.

Figure 4-2: Typical microATX (left) and ATX motherboards

In 2004, Intel began shipping motherboards based on a new form factor, called BTX (Balanced Technology eXtended). Although BTX is a derivative of ATX, BTX cases and motherboards are physically incompatible with ATX components. Intel had hoped that BTX would take the market by storm, but as of early 2006 BTX had made only minimal inroads in the PC market.

BTX may be a solution in search of a problem. The original goal of BTX was to improve cooling at a reduced noise level: a necessary improvement, given the very high heat production of Intel Pentium 4 processors, some of which consume 130W. Now that Intel is shifting processor production to low-power cores that consume as little as 20W, there is no longer a real need for BTX.

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

A motherboard is so complex and has so many components and connections that it can be overwhelming to someone who is not used to working inside PCs. As is true of many things, though, the easiest way to understand the working of the whole is to understand the working of the individual parts. So let's take the $2 tour of a modern motherboard, where you'll learn the functions of each important component and how to identify those components visually.

To begin, let's examine a block diagram of a chipset. Figure 4-4 shows the major components and functions of the Intel 925XE chipset. (Other modern chipsets are similar.) The 925XE chipset uses two physical chips. The north bridge chip, which Intel calls the MCH (Memory Controller Hub), is the blue box labeled 82925X MCH. The MCH arbitrates and coordinates communications between the processor, memory, and the PCI Express video adapter. The MCH provides very high bandwidth channels: 6.4 GB/s between the MCH and processor; 8.0 GB/s between the MCH and the video adapter; and 8.5 GB/s between the MCH and memory.

Figure 4-4: Block diagram of the Intel 925X chipset (image courtesy of Intel Corporation)

The south bridge chip, which Intel calls the ICH (I/O Controller Hub), is the blue box labeled ICH6RW. The ICH handles input/output functions, which work at much lower data rates than the processor, memory, and video channels. These channels include four 150 MB/s Serial ATA ports, six PCI slots with a cumulative 133 MB/s bandwidth, eight USB 2.0 ports with 60 MB/s bandwidth each, and four 500 MB/s PCI Express x1 slots. The ICH also handles such functions as embedded audio, the interface with the system BIOS, and wireless networking.

Figure 4-5 maps these chipset features to the component layout on a real-world motherboard. For illustrative purposes, we've used an Intel D925XECV2 motherboard, but any recent motherboard has similar features and layout. Not all of the components shown are present on all motherboards, and the exact positioning of some components may differ, but the essentials remain the same.

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

When you upgrade other system components, it's sometimes important to know the details of the motherboard and chipset you're using. The motherboard's manual and manufacturer's web site are authoritative sources of information, of course, but at times you won't be certain which motherboard is installed in the system. The easiest way to identify the motherboard and chipset is to run a diagnostic utility such as Everest Home Edition. Figure 4-11 shows Everest Home Edition identifying a motherboard as an ASUS A7N8X-VM/400, with BIOS version 1003, dated 08/06/2004. Figure 4-12 identifies the chipset in this motherboard as an NVIDIA nForce2 IGP north bridge with an NVIDIA MCP2 south bridge.

Figure 4-11: Everest identifies a motherboard as an ASUS A7N8X-VM/400

Figure 4-12: Everest identifies the chipset as an NVIDIA nForce2

Alas, it's not always possible to take the easy way out. Sometimes you have to pop the cover and actually examine the motherboard to get the information you need, because motherboard makers make slipstream revisions to their products without changing the model number. For example, an earlier revision of a motherboard may use voltage regulator modules (VRMs) that are rated to provide enough current only for processors that run at 2.8 GHz or slower. A later revision of that board, with the identical model number, may use VRMs that are rated for processors up to 3.8 GHz.

The revision number of a motherboard is ordinarily silk-screened on the board or printed on a paper label that is stuck to the board somewhere near the silkscreened model number or serial number. Most motherboard makers call their revisions by that name. Intel instead refers to its revision levels as AA numbers (Altered Assembly numbers). Figure 4-13 shows the label area of an Intel D865GLC motherboard, with an AA number of C28906-403

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

The exact steps required to replace a motherboard depend on the specifics of the motherboard and case, the peripheral components to be connected, and so on. In general terms, the process is quite simple, if time-consuming:

Disconnect all cables and remove all expansion cards from the current motherboard.
Remove the screws that secure the old motherboard and remove the motherboard.
If you are reusing the CPU and/or memory, remove them from the old motherboard and install them on the new one.
Replace the old back-panel I/O template with the template supplied with the new motherboard.
Remove and install motherboard mounting posts as necessary to match the mounting holes on the new motherboard.
Install the new motherboard and secure it with screws in all mounting hole positions.
Reinstall all of the expansion cards and reconnect the cables.

The devil is in the details. In the rest of this section, we'll illustrate the process of installing the motherboard and making all the connections properly.

Before you start tearing things apart, make sure you have at least one good backup of all your important data. You needn't worry about backing up Windows and applications—although you should, if possible, back up the configuration information for your mail client, browser, and so on—because unless you're replacing an old motherboard with an identical new motherboard, you may need to reinstall Windows and all applications from scratch.

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

The motherboard is the computer, so the usual symptom of a failed motherboard is a completely dead system. Fans, drives, and other peripherals may spin up if the motherboard is dead, but more often nothing at all happens when you turn on the power. No beeps, no lights, no fans, nothing.

If you think you have a dead motherboard, think again. The most likely cause of a dead system is a blown fuse or breaker at the wall receptacle. If you're certain the system is getting power and you have just installed the motherboard, it's much more likely that you've neglected to connect a cable or made some other basic error than that the motherboard itself is bad, assuming of course that the problem motherboard is a highquality product.

Many online vendors have stopped accepting returns of "bad" motherboards for just this reason. As it turns out, about 19 of 20 motherboards returned as defective are perfectly good. The buyer simply didn't install the motherboard correctly. Even so, many upgraders choose to buy their motherboards from a big-box store or other local source, because of their generally better return policies. In fact, some people troubleshoot their systems by buying a motherboard locally and then returning it if the motherboard turns out not to be the problem. We think that's unethical, but as any vendor will tell you, it's common practice.

Most name-brand motherboards, particularly those made by Intel and ASUS, are of very high quality; cheap motherboards, including those used in most consumer-grade mass-market systems, are of very poor quality. We've used Intel and ASUS motherboards for years. In a shipment of 100 motherboards, it's unusual to find even 1 DOA. In a shipment of 100 cheap motherboards, it's not uncommon to find half or more DOA, and many of the remainder failing soon after they're installed.

In a working system, it's very uncommon for a high-quality motherboard to fail other than from lightning damage (see Chapter 16) or other severe abuse. In particular, it's nearly unheard of for a motherboard to fail while it is running, as opposed to when you start the system. A dead system is more often caused by a dead power supply than a dead motherboard, so the first step to troubleshoot an apparently dead motherboard is to swap in a known-good power supply. If the system remains completely dead with a known-good power supply, it's likely that the motherboard is defective and must be replaced.

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

In This Chapter

The Truth About Processor Performance
Processor Characteristics
Processor Types
CPU Coolers
Processor Upgrade Considerations
Replacing the Processor
Troubleshooting Processors

The processor, also called the CPU (Central Processing Unit), is the engine that drives the system. Replacing the processor requires some careful research to ensure that the new processor is compatible with the current motherboard and other system components, but a processor swap, properly done, can be one of the highest bang-for-the-buck upgrades you can make. In some cases, you can double or even triple overall system performance by spending $50 to $100 on a new processor. In this chapter, we tell you everything you need to know to choose and install a replacement processor.

Processor companies do nothing to discourage longstanding myths about processor performance. It's true that in the early days of microprocessors, a new model was often two or even three times faster than the model it replaced and sold for little or no more. In those halcyon days, the fastest available processors were sometimes 10 times faster than less expensive models that were still being sold.

There was also a favorable bang-for-the-buck ratio. If you paid twice as much for a processor, it was probably considerably more than twice as fast. We remember testing our 4.77 MHz IBM PC/XT against a 16 MHz 286 PC/AT when both were still being sold. The latter system cost two or three times as much, but was something like 10 times faster.

Those days are long past. Nowadays, processor performance increases incrementally, the accompanying price differences are large, the performance gap between the slowest and fastest current models has narrowed substantially, there are many, many more intermediate models available with minor performance differences, and the bang-for-the-buck ratio for the fastest processors has dropped well below 1:1. AMD and Intel have both learned to "work the market," maximizing their revenue in a very competitive market.

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

Processor companies do nothing to discourage longstanding myths about processor performance. It's true that in the early days of microprocessors, a new model was often two or even three times faster than the model it replaced and sold for little or no more. In those halcyon days, the fastest available processors were sometimes 10 times faster than less expensive models that were still being sold.

There was also a favorable bang-for-the-buck ratio. If you paid twice as much for a processor, it was probably considerably more than twice as fast. We remember testing our 4.77 MHz IBM PC/XT against a 16 MHz 286 PC/AT when both were still being sold. The latter system cost two or three times as much, but was something like 10 times faster.

Those days are long past. Nowadays, processor performance increases incrementally, the accompanying price differences are large, the performance gap between the slowest and fastest current models has narrowed substantially, there are many, many more intermediate models available with minor performance differences, and the bang-for-the-buck ratio for the fastest processors has dropped well below 1:1. AMD and Intel have both learned to "work the market," maximizing their revenue in a very competitive market.

Here's a dirty little secret that AMD and Intel would rather you not know. At any given time, the actual performance differences between their slowest and least expensive "economy" processors and their fastest and most expensive "performance" processors is relatively small. A $750 processor you can buy today will probably be at most 2.5 to 3 times faster than the $50 processor sitting next to it on the store shelf.

Doubling or tripling performance may sound like a huge improvement, but human perception is not linear. A processor must be 30% to 50% faster than another processor before most people perceive any noticeable difference in routine use. Doubling processor speed results in an obvious difference in performance, but not a knock-your-socks-off change. Tripling processor speed provides a very noticeable performance boost, but at a very high price.

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

Here are the important characteristics of processors:

Processor make and model

The primary defining characteristic of a processor is its make—AMD or Intel—and its model. Although competing models from the two companies have similar features and performance, you cannot install an AMD processor in an Intel-compatible motherboard or vice versa.

Socket type

Another defining characteristic of a processor is the socket that it is designed to fit. If you are replacing the processor in a Socket 478 motherboard, for example, you must choose a replacement processor that is designed to fit that socket. Table 5-1 describes upgradability issues by processor socket.

Table 5-1: Upgradability by processor socket type
Socket	Upgradability	Original processor	Upgrade processors	Considerations
Slot 1	None	Pentium II/III, Celeron	None	Slot 1 systems are not economically upgradable.
Slot A

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|Buy reprint rights for this chapter

A few years ago, choosing a processor was pretty straightforward. AMD and Intel each produced two series of processors, a mainstream line and a budget line. Each company used only one processor socket, and there was a limited range of processor speeds available. If you wanted an Intel processor, you might have a dozen mainstream models and a half-dozen budget models to choose among. The same was true of AMD.

To further confuse matters, most AMD and Intel processors are available in two types of packaging, called OEM and retail-boxed. OEM processor packages include only the bare processor and usually provide only a 90-day warranty. Retail-boxed processors include the processor, a compatible CPU cooler, and a longer warranty, typically three years.

A retail-boxed processor is usually the better deal. It typically costs only a few dollars more than the OEM version of the same processor, and the bundled CPU cooler is usually worth more than the price difference. But if you plan to install an after-market CPU cooler—for example, because you are upgrading your system to be as quiet as possible—it may make sense to buy the OEM processor.

Nowadays, choosing a processor isn't as simple. AMD and Intel now make literally scores of different processor models. Each company now offers several lines of processors, which differ in clock speed, L2 cache, socket type, host-bus speed, special features supported, and other characteristics. Even the model names are confusing. AMD, for example, has offered at least five different processor models under the same name—Athlon 64 3200+. An Intel Celeron model number that ends in J fits Socket 775, and the same model number without the J designates the same processor for Socket 478. A Pentium 4 processor model number that ends in J says nothing about the socket type it is designed for, but indicates that the processor supports the execute-disable bit feature. And so on.

AMD and Intel each offer the three categories of processors described in the following sections.

Additional content appearing in this section has been removed.
Purchase this book now or read it online at Safari to get the whole thing!

Content preview·Buy PDF of this chapter|

Table of Contents

Section 3.2.1.1: Backup hardware