Introduction to PC Troubleshooting - DEMO

Introduction

Welcome to Introduction to PC Troubleshooting!

My name's Scott Jernigan, and I'm your instructor. I've been teaching about computer hardware and software since the mid-1990s, when I left grad school with a master's degree in medieval history. (I know, medieval history goes so well with cutting-edge technology!)

I've been teaching online classes for many years and just love the format. The pacing works for almost everyone, and the discussion areas get lively. So let's get to it!

Love them or hate them, personal computers (PCs) are everywhere. They surround us at work, home, and school, quietly doing our bidding (at least until the imminent robotic uprising begins). Even with the popularity of smartphones and tablets, you likely need a PC to get things done.

Unfortunately, PCs aren't perfect. They lock up. They break. They shut down unexpectedly. A small fire emerges from the back of the case—okay, maybe I'm exaggerating. But for all of the technology advancements in the past several years, PCs aren't perfect (yet).

When something breaks, we want to throw it away and replace it. Think about it: How many toasters have you gone through? But a toaster is cheap. PCs are not. Unless you have money to burn (in which case, can we talk?), your best bet is to fix whatever's wrong with the problem computer.

This is, without exception, a pain. When a computer stops working, it doesn't tell you why. Nor does it explain where to look for the problem or how to fix it when you find it. Even a seasoned PC tech won't know right away. It usually takes a little detective work to track down the issue.

This course unleashes your PC detective. You'll learn how to fix many common (and some uncommon) PC problems. Some things can't be fixed—a monitor with a big hole in it is beyond saving—but you can repair a lot with just a few new parts or tweaked settings.

This course begins by introducing you to two very important processes: the computing process, or how computers work, and troubleshooting theory, or how to track down and solve problems.

Following this, I'll go into more depth in three areas: the operating system, the Internet, and hardware. For each area, I'll provide an overview. I'll then discuss how to fix the most common problems in each area. Finally, you'll learn how to prevent problems.

The final lesson of this course is a review, using real-world scenarios to walk you through fixing multiple computer problems. At the end of this course, you should be able to use your technical and problem-solving skills to fix troublesome PCs. Good luck!

Note

This course focuses on how to troubleshoot computers that are running Microsoft Windows. The discussion about how computers work and troubleshooting methodology applies to all computers, but the rest of the course doesn't cover Macintosh or Linux machines.

Now that we've talked about the course in general, let me give you a preview of this lesson in particular. First, we'll look at input devices, or how you tell the computer to do stuff. Then we'll explore the pieces that do the work inside the computer. The final section describes the output devices, where the computer communicates to the user.

If you have a question or problem related to the course, you can always click the Discussion link at the top or bottom of any page in the classroom. I'm here to help!

Input Devices

Most of the time, you probably sit at your computer and assume it'll work. It doesn't matter how it works, just that it does. That's fine for a regular user, but if you want to troubleshoot PCs, you'll need to know how computers work. This includes the hardware, software, and operating system.

A desktop computer

Computers work through a three-stage process. You start the action by doing something: clicking the mouse, typing on the keyboard, or touching a touch screen. This is input.

Then the parts inside the device or case take over, and the operating system instructs the hardware to do what you've requested. This is processing.

Once the computer has processed your request, it shows you the result by changing what you see on the monitor or playing a sound through the speakers. This is output.

The animation below demonstrates the basics of the computing process. Even an action that seems simple, such as typing words into a Word document, requires many things to happen within the computer.

Note

There's a fourth step: data storage. It's not an essential piece of the computing process puzzle, but it's important if you want to save something and work on it again later.

It all begins with input: you do something with a device attached to the rest of the computer, and something happens because of it. By far, the most common input devices are the keyboard and mouse. With these devices, called peripherals, you can tell the computer to do something. They've been around for a long time and won't be going away anytime soon. Let's take a look at each of them.

Keyboards

The keyboard enables you to communicate with the processing parts of the computer (which we'll get to in Chapter 3). How you use a keyboard changes with each application. In a word-processing program like Microsoft Word, for example, you'd use the keyboard to type letters, essays, and other documents. In a typical video game, however, the keys on a keyboard might control how your character moves, jumps, or casts spells.

A keyboard

Standard keyboards in English-speaking countries have the same layout, called QWERTY, which refers to the first six keys on the top row of the keyboard. Above the letters are the numbers, and above them are the function keys. Function keys change depending on the program, but for the most part, F1 is Help. Other keys on a Windows keyboard include ESC, TAB, CAPS LOCK, SHIFT, CTRL, ALT, and WINDOWS.

Note

Not every language uses the same alphabet, which is one of the reasons that different regions use different keyboard layouts. PC experts call this regionalization. A Spanish keyboard would add Spanish-only letters, while a German keyboard would add German-only letters. Not only that, but other letters move around as well. German keyboards, for example, swap the positions of the Y and Z keys. Be careful before you sit down at a foreign keyboard—the letter keys might not be where you left them.

Keyboards use one of two connectors to plug into a computer. The older style is a PS/2 or mini-DIN connector. It's round, with six pins. More recent keyboards use a rectangular Universal Serial Bus (USB) connector. All connectors use a tab or a special shape to make sure you plug them in correctly. 

A PS/2 connector on the left and a USB connector on the right

In Windows, the Keyboard applet in the Control Panel configures the keyboard. You'll learn a lot more about the Control Panel in a later lesson on operating systems. For now, know that you can configure keyboards from within Windows. For example, you can adjust how quickly a key repeats while someone holds it down.

The Keyboard applet

Mice and Other Pointing Devices

Using a mouse or another pointing device enables you to move a cursor around the screen and click things. A computer mouse usually has two buttons (although mice designed for Apple computers famously had only one for a long time). Here's what the different buttons do:

• Left-clicking selects something on the screen.
• Right-clicking reveals information about what you click. This information appears in a context menu.
• Double-clicking usually performs an action. For instance, double-clicking a desktop icon usually opens a program.

A two-button mouse with a scroll wheel

Newer mice often have a scroll wheel between the left and right mouse buttons. Spinning the wheel enables you to move up and down in a window.

Mice originally came with a ceramic ball on the bottom. When you rolled the mouse around, sensors inside the mouse tracked that movement and input that information into the computer. The ball would easily pick up dirt and needed to be cleaned often. Ball mice, as people called them, were eventually replaced by optical mice, which use a red light to keep track of their movement. These don't need cleaning, since there are no moving parts.

Mice and other pointing devices use one of two connectors to plug into a computer, just like the keyboard. Older devices use the mini-DIN or PS/2 connector, while newer ones use a USB connector. 

Alternatives to Mice

Mice are the most common tool used to move the cursor around the screen, but there are others. A trackball is like an inverse mouse: the ball is on top, and you rotate it with your fingers. And many laptops use a touchpad. You drag your finger across the pad, and the cursor moves accordingly.

Like keyboards, mice and other pointing devices also get their own Control Panel applet in Windows. The Mouse applet enables you to change how fast the cursor moves and how fast you need to double-click to open a program.

The Mouse applet

Now that we've talked about the outside of the computer, let's get into the guts. When you're ready, move ahead to Chapter 3 to find out about a computer's processing components.

Processing Components

After you input something, the computer needs to process that information before it can give you output. Think of it this way: when you press a key on a keyboard with a word-processing program open, a letter appears. But a keyboard has no clue how to control what appears on a monitor. There are many steps between input and output—between the commands you give and the words or pictures or sounds the computer produces. This is processing.

Processing usually goes something like this: You input a command using a mouse or another device. The central processing unit (CPU) receives the instruction. A CPU is sort of like the brain of the computer. It pulls data from random access memory (RAM), calculates something, and then spits out the results to an output device.

What's RAM?

Random access memory is a kind of bridge between processing and data storage. Most data gets stored on hard drives, but these send and receive data too slowly for a processor. Instead, the hard drive sends that data to the RAM to be held until the processor needs it. RAM can send and receive data much faster than a hard drive, but its capacity is limited. We'll talk more about RAM at the end of this chapter.

"Processing" sounds complicated and abstract. Put simply, processing is math. Modern processors can perform over 3 billion calculations per second! Try adding 347 + 256 that fast! That speed is why processors seem like magic. They perform so many calculations per second that you can watch movies, play games, or talk to friends over the Internet. And it's all possible because of math.

The Basics of CPUs

Because the central processing unit plays a central role in just about everything that happens with the PC, understanding how CPUs work and how to compare one to another helps in the troubleshooting process. CPUs rarely break, but they can be a bottleneck on an ailing computer. Learning the basics here helps you factor in the CPU when troubleshooting.

A CPU

Two companies make the vast majority of CPUs, also called microprocessors: Intel and Advanced Micro Devices (AMD). Intel produces the more popular and faster CPUs of the two companies, while AMD makes more affordable CPUs that are still of high quality.

Plugging a CPU into a motherboard connects it to the rest of the computer components.

A motherboard

Think of a motherboard as a chassis for a car: everything else attaches to it, including RAM, hard drives, video cards, and so on. Motherboards are designed to handle a specific brand and style of CPU. For instance, Intel CPUs don't work on AMD motherboards.

A stick of RAM

CPUs are measured by their speed and their sophistication. In terms of CPUs, speed means how many things it can do in one second. Each thing is known as a cycle. Completing one cycle is 1 hertz (Hz). A million cycles is a megahertz (MHz), and a billion cycles is a gigahertz (GHz).

A few years ago, CPUs reached a maximum speed of about 4 GHz. The physical materials of the processor couldn't handle any more. The chip manufacturers quickly changed both their marketing and their processor development strategy.

Once CPU speeds hit their limit, Intel and AMD needed to find new ways of increasing processor power. To accomplish this, they did four things:

• Switched from 32-bit to 64-bit computing (we'll talk more about this in a minute)
• Added multiple cores to a single processor chip
• Refined how efficiently CPUs worked with applications
• Optimized performance by using special RAM called cache

From 32-Bit to 64-Bit Processing

For more than a decade, all CPUs had a 32-bit architecture: A CPU could handle data that was 32 bits in complexity (or numbers up to about 4 billion). It could also handle an operating system or application with up to 4 billion lines of code.

Today's 64-bit processors are a huge stride forward. From a binary math standpoint, doubling the complexity of an operating system, application, or processor requires just one more bit. Each bit added, therefore, doubles the complexity. That means that 32 bits doubled is only 33 bits. Double that again and it's 34 bits. You get the idea.

So, how complex is 64-bit computing? A 64-bit CPU can easily handle numbers up to . . .  

18,446,744,073,709,551,615

Yeah, I don't know what that number is either, but the CPU can handle an operating system or application with that many lines of code.

Do They Work Together?

64-bit CPUs work with older 32-bit operating systems and applications as well as 64-bit ones, but not the other way around. A 32-bit processor can't run a 64-bit operating system. 

Both Intel and AMD decided at about the same time to combine multiple CPUs onto a single chip, creating multicore processors. This increases processing capability and efficiency because each core can pick up the slack when another core gets too busy. Today, CPU manufacturers offer processors with two (dual-core), four (quad-core), six (hexa-core), and more cores on a single chip.

CPUs and Applications

CPUs have a preset list of commands they understand, called the codebook or instruction set. Programmers write applications in different computer languages, which are translated into code understood by the CPU's instruction set. The processor works through the code and outputs commands to various parts of the computer.

Every processor works with data differently. Two CPUs with the same clock speed won't always process the same data in the same amount of time. Each CPU has its own strengths and weaknesses, and each will handle certain tasks faster or slower because of them. In addition, a processor with a faster clock speed from an older generation will handle tasks more slowly than a processor with a slower clock speed from this generation.

You'll recall that processors pull data for running applications from RAM; it's the only way the CPU can retrieve data fast enough to function properly. Years ago, CPU makers discovered that by adding a little bit of super-fast RAM directly onto the CPU, they could greatly speed up the whole computing process. We call this super-fast RAM cache, which rhymes with cash.

Today's CPUs have several levels of cache, called level 1 (L1), level 2 (L2), and, on the highest-end processors, level 3 (L3). Most commonly, L1 is the smallest and fastest, L2 is bigger but slower, and L3 is the biggest and slowest type of cache. Note that all cache is so fast that it can run circles around regular system RAM.

Here's the general rule on cache: More cache overall makes for a more efficient (and more expensive) CPU.

So that's what's going on inside your computer! When you're ready, head over to Chapter 4, where we'll talk about output . . . that's when your computer talks back to you.

Output Devices and Data Storage

After your computer processes the input commands you give it, it gives you feedback in the form of output devices. Without output, you'd have no way of knowing whether your commands were completed. The two primary output devices are monitors (which are essential) and speakers (which aren't).

All About Monitors

The monitor is the primary output device for the computer. It displays the results of input and the computer's processing. This could be anything from going through a level of an intense action game to moving your cursor across the desktop. When most people think about their interactions with a computer, they're probably thinking about what happens on the monitor. Every monitor has the same basic components. The most important part is, of course, the display itself.

You can power the display on and off and adjust other settings using a set of buttons that are usually on an edge of the monitor. Pressing the Menu button opens an on-screen menu that enables you to adjust the brightness, contrast, color balance, size, and position of the display.

The back of the monitor has connections for receiving a video signal from the computer and power from a wall outlet.

There are two varieties of monitors: CRT and LCD. Cathode-ray tube (CRT) monitors use the same technology as old televisions. CRTs are the big beige boxes you saw on every office desk from the time people first had computers up until several years ago.

A CRT monitor

A Note About Safety

CRT monitors are large, heavy, and power-hungry . . . so power-hungry that you should never try to open one up. With 30,000 volts swimming around inside even hours after a monitor's been unplugged, opening one can kill you. Don't do it!

Liquid crystal display (LCD) monitors are much thinner than their CRT siblings, saving on desk space. They're also lighter and use less power. Most LCDs today also have a widescreen aspect ratio. Instead of being almost square, like old televisions, these monitors are much wider than they are tall—great for looking at two documents side by side (or watching movies).

An LCD monitor

Either type of monitor connects to the computer's video card. The video card has its own processor called a GPU, which is short for graphics processing unit. The GPU helps the CPU and operating system change the image on the display.

Monitors connect to the video card using a cable with one of three connectors.

The oldest connector type is the blue Video Graphics Array (VGA) connector. It has 15 pins, laid out in three rows of five. Most CRT monitors use VGA connectors, but you can find them on many LCD monitors, too.

A VGA connector

Today's most commonly used connector is the white Digital Visual Interface (DVI) connector. Depending on the monitor, the connector can have up to 29 pins.

A DVI connector

You can use the High-Definition Multimedia Interface (HDMI) connector for video and audio signals, whereas VGA and DVI carry video signals only. HDMI is on more HD televisions than monitors, but it's becoming more popular with computers. It uses a connector that looks somewhat like USB but fits only in HDMI ports.

An HDMI connector

. . . And One More

A couple of manufacturers, notably Dell, use a video connector called DisplayPort. DisplayPort connectors are smaller than HDMI but, at this time, they haven't been widely adopted in the PC industry.

In addition to the physical buttons on your monitor, the Personalization applet in Windows also controls the appearance of your display. You can use it to customize the look and feel of Windows, plus you can address the more technical details of how your monitor functions.

One section of Personalization, called the Display Settings, enables you to change the monitor's resolution, which means how large or small things appear on the screen.

In technical terms, the resolution determines the number of pixels the monitor uses to create the image. (A pixel, or picture element, is a single dot or small square that changes colors to create a picture on your display.) Resolution is the number of pixels across by the number of pixels down. For instance, my monitor uses 1,920 pixels by 1,080 pixels, or 1920 × 1080. When you multiply those numbers, you get the total number of pixels that the monitor uses: 2,073,600!

Pixels on a monitor

With the Display Settings, you can adjust the resolution of your monitor from 800 × 600 all the way up to the maximum (or native) resolution of your monitor. Keep in mind that as you adjust the resolution, the size of windows and icons will change, too. With an LCD, things will appear large but blurry at low resolutions. At high resolutions, things will be sharp, but it can be tough to read what anything says.

Adjusting the screen resolution in Windows 7

Note

Older versions of Windows, such as Windows XP, have a Control Panel applet called Display that functions just like the Display Settings section of Personalization. You could set the resolution even lower in the Display applet, down to 640 × 480.

To change the resolution in Windows Vista or Windows 7, go to Start > Control Panel > Adjust screen resolution if you're in Category view. In Classic view, double-click Personalization and then click Display Settings. Click the Resolution drop-down menu and use the slider to make your choice.

Speakers

Sound controllers enable the computer to play sound and to record it. All modern computers come with sound controllers built into the motherboard. (Older computers that didn't have built-in sound came with an add-on sound card.)

The simplest sound controllers have three 3.5-millimeter audio ports, called jacks. More complex sound controllers have five or six jacks. Each jack has a specific purpose, such as audio out for connecting to speakers or headphones. Most sound controllers have color-coded jacks for the specific connections.

Audio ports on a sound controller

The computer uses the sound processor and audio software to play music and sounds through speakers or headphones.

Better motherboards offer high-definition, or HD, audio processors. One HD standard licensed by Intel, the CPU maker, is called Azalea. Typical audio software includes the Windows Media Player, which comes with Windows, and Apple iTunes, which you can download from apple.com.

Do yourself a favor if you can afford it and replace an inexpensive pair of speakers with a high-quality 2.1 rig from Klipsch (my favorite) or Logitech. The 2 refers to the pair of stereo speakers or satellites. The 1 refers to the subwoofer that provides the bass. The difference in the sound experience between a pair of under-$50 speakers and a $100–to-$150 2.1 set is simply stunning. Your ears will love you for it.

A set of speakers

Data Storage

I said there were three parts of the computing process (input, processing, and output), but if you want to keep any work you do on a computer, you need data storage. A processor works with the data it reads from RAM, but when the computer's turned off, the data in RAM disappears. Poof. Data storage is how you can save things and come back to them later.

Hard drives store operating systems (OSs), applications, and data so that they're available when the PC powers up. Because they store data, hard drives hold a central place in the computer. If the drive dies, all the data dies, too—and that's not a good thing!

Traditional hard drives read to and write from disks called platters, enclosed in a metal case. Newer hard drives, called solid-state drives, use memory chips (like those found in memory cards for digital cameras) to store data.

Inside a traditional hard drive

Other forms of data storage include flash memory cards and optical discs (like CDs, DVDs, and Blu-ray discs).

Optical discs

Whew, that was a lot to take in! Get up and stretch if you need to. Then head over to Chapter 5 for a quick summary of all you've learned today.

Summary: Why Learn All These Terms and Names and Details?

You can't fix something if you don't know how it works. The computing process forms the foundation of everything we do on a computer. You can break down every task you perform into input, processing, and output. These principles will help you later, when you learn to track down problems and fix them. One of the questions you'll need to ask yourself is "Is this an input problem, a processing problem, or an output problem?" Once you know that, it'll be much easier to troubleshoot the issue.

What's next? In Lesson 2, we'll discuss troubleshooting theory, including the steps you need to take to solve a problem. You'll identify and analyze a problem, come up with a possible solution, test it, and then record your findings so you can prevent problems from happening again.