CompTIA A+ Chap 1 PDF

4 CompTIA A+: Guide to IT Technical Support Introduction Like many other computer users, you have probably used your personal computer to play games, check your email, write papers, or build Excel worksheets. This text takes you from being an end user of your computer to becoming an in...

4 CompTIA A+: Guide to IT Technical Support Introduction Like many other computer users, you have probably used your personal computer to play games, check your email, write papers, or build Excel worksheets. This text takes you from being an end user of your computer to becoming an information technology (IT) support technician able to support all types of personal computers. The only assump- tion made here is that you are a computer user—that is, you can turn on your machine, load a software package, and use that software to accomplish a task. No experience in electronics is assumed. As an IT support technician, you’ll want to become A1 certified, which is the industry standard certification for IT support technicians. This text prepares you to pass the A1 220-1101 Core 1 and 220-1102 Core 2 exams by CompTIA (comptia.org). The exams are required by CompTIA for A1 certification. In this module, you take apart and reassemble a desktop computer and laptop while discovering the various hardware components inside the cases. You also learn about the tools you need to work inside the case. Exam Tip As you work your way through the modules and the appendix, notice the A1 Core 1 and Core 2 exam objective numbers that follow certain headings. This information identifies how the content maps to the exam objectives. In the text, A1 Core 1 objective numbers are tagged in teal, and A1 Core 2 objective numbers are tagged in orange. After studying each module or appendix, take a look at the grid at the beginning of this text, and make sure you understand each objective listed in the grid for the module or appendix just completed. Taking apart and servicing a computer are tasks that every A1 certified technician needs to know how to do. As part of your preparation to become A1 certified, try to find old desktop and laptop computers you can take apart. If you can locate the service manual for a laptop, you should be able to take it apart, repair it (assuming the parts are still available and don’t cost more than the computer is worth), and get it up and running again. Have fun with this module, and enjoy tinkering with these computers! Exploring a Desktop Computer Core 1 Objectives 1.1, 2.8, 3.1, 3.2, 3.3, 3.4, 3.5 In this section of the module, you learn how to take apart a desktop computer and put it back together. This skill is needed in this module and others as you learn to add or replace computer parts inside the case and perhaps even build a system from scratch. As you read the following steps, you might want to refer to the Hands-On Projects at the end of the module, which allow you to follow along by taking a computer apart. As you do so, be sure to follow all the safety precautions found in the appendix “Safety Procedures and Environmental Concerns.” In the steps that follow, each major computer component is identified and described. You learn much more about each component later in the text. Take your time—don’t rush—as you take apart a computer for the first time. It can be a great learn- ing experience or an expensive disaster! As you work, pay attention to the details and work with care. Protecting Yourself and the Equipment Core 1 Objectives 1.1, 3.4 Protecting yourself and the equipment is essential for having a positive experience working inside a computer. When you follow the safety guidelines, you will be more likely to successfully complete your task and enjoy yourself while doing it. Remember to always ask your instructor for help if you have any questions about safety. Follow these guidelines to protect yourself: Remove loose jewelry that might get caught in cables and components as you work. As you work, watch out for sharp edges on computer cases that can cut you. Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.  Module 1 Taking a Computer Apart and Putting It Back Together 5 Consider the monitor and the power supply to be “black boxes.” Never remove the cover or put your hands inside this equipment unless you know about the hazards of charged capacitors and have been trained to deal 1 with them. The power supply and monitor contain enough power to kill you, even when they are unplugged. Power down the system and unplug it. For a computer, press and hold down the power button for three seconds to completely drain any residual power in the power supply. Never, ever touch the inside of a computer that is turned on. The one exception to this rule is when you’re using a multimeter to measure voltage output. Follow these guidelines to protect the equipment: Always wear an ESD strap (also called a ground bracelet, antistatic wrist strap, or ESD bracelet), which pro- tects against electrostatic discharge when working inside the computer case. Electrostatic discharge (ESD) is another name for static electricity, which can damage chips and destroy motherboards, even though it might not be felt or seen with the naked eye. When you use the strap to connect or ground your hand to the case, as shown in Figure 1-1, any static electricity between you and the case is dissipated. Figure 1-1 An ESD strap, which protects computer components from ESD, can clip to the side of the computer case and eliminate ESD between you and the case If an ESD strap is unavailable or won't work, use a ground mat, also called an ESD mat, to dissipate ESD (see Figure 1-2). While the equipment is resting on the ground mat, it is protected from ESD; however, if you lift the equipment off the mat, it is no longer protected, unless you are wearing an ESD strap. Figure 1-2 An ESD mat dissipates ESD and should be connected to the ground Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 6 CompTIA A+: Guide to IT Technical Support Place equipment in a static shielding bag, also called an antistatic bag. These bags act as a type of Faraday cage, named after Michael Faraday, who built the first cage in 1836. A Faraday cage is any device that pro- tects against an electromagnetic field. Save antistatic bags as you find them, and use them whenever you take a piece of equipment out of a computer. Remember that a device that is set on top of an antistatic bag is not protected; it is only protected when it is placed inside the bag (see Figure 1-3). Figure 1-3 An antistatic bag helps protect components from ESD Don’t stack boards on top of each other. You could accidentally dislodge a chip this way. When you remove a circuit board or drive from a computer, carefully lay it on an antistatic mat or set it in an antistatic bag in a place where it won’t get bumped. When handling motherboards, cards, or drives, don’t touch the chips on the device. Hold expansion cards by the edges. Don’t touch any soldered components on a card, and don’t touch the edge connectors unless it’s absolutely necessary. All this helps prevent damage from static electricity. Also, fingerprints on the edge connectors can cause later corrosion. To prevent damage to a microchip, don’t touch it with a magnetized screwdriver. Core to Core It’s important to know how to stay safe when working inside computers. Before opening a computer case and using the tools described in this section, be sure to read the appendix “Safety Procedures and Environmental Concerns.” As you work inside a computer, follow all the safety guidelines discussed in that appendix. Step 1: Planning and Organizing Your Work and Gathering Your Tools Core 1 Objectives 2.8, 3.4 When you begin to learn how to work inside a computer case, make it a point to practice good organizational skills. If you keep your notes, tools, screws, and computer parts well organized, your work goes more smoothly and is more fun. Here are some tips to keep in mind: As you work, make notes using pencil and paper, and perhaps take photos with your cell phone so you can backtrack later if necessary. (When you’re first learning to take a computer apart, it’s easy to forget where everything fits when it’s time to put the computer back together. Also, in troubleshooting, you want to avoid repeating actions or overlooking things to try.) Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.  Module 1 Taking a Computer Apart and Putting It Back Together 7 To stay organized and avoid losing small parts, keep screws and spacers orderly and in one place, such as a cup or tray. 1 In a classroom environment, after you have reassembled everything, have your instructor check your work before you put the cover back on and power up. Tools Used by a Computer Hardware Technician Every IT support technician who plans to repair desktop or laptop computers or mobile devices needs a handy tool- box with a few essential tools. Several hardware and software tools can help you maintain a computer and diagnose and repair computer problems. The tools you choose depend on the amount of money you can spend and the level of hardware support you expect to provide. Essential tools for computer hardware troubleshooting are listed here, and several of them are shown in Figure 1-4. You can purchase some of these tools in a computer toolkit, although most toolkits contain items you really can do without. Figure 1-4 Tools used by IT support technicians when maintaining, repairing, or upgrading computers Here is a list of essential tools: An ESD strap (also called a ground bracelet) Flathead screwdriver Phillips-head or crosshead screwdriver Torx screwdriver set, particularly size T15 Tweezers, preferably insulated ones, for picking pieces of paper out of printers or dropped screws out of tight places Software, including recovery DVDs or USB recovery drives for any operating system (OS) you might work on (you might need several, depending on the OSs you support), antivirus software on bootable DVDs or USB flash drives, and diagnostic software The following tools might not be essential, but they are very convenient to have on hand: Cans of compressed air (see Figure 1-5), small portable compressor, or antistatic vacuum cleaner to clean dust from inside a computer case Cleaning solutions and pads such as contact cleaner, monitor wipes, and cleaning solutions for CDs and DVDs Multimeter to check cables and the power supply output Power supply tester POST diagnostic cards Needle-nose pliers for removing jumpers and for holding objects in place while you screw them in (especially handy for those pesky nuts on cable connectors) Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 8 CompTIA A+: Guide to IT Technical Support Figure 1-5 A can of compressed air is handy to blow Cable ties to keep cables out of the way inside dust from a computer case a computer case Flashlight to see inside the computer case AC outlet ground tester Network cable tester Loopback plugs to test ports Small cups or bags to help keep screws orga- nized as you work Antistatic bags to store unused parts Pen and paper for taking notes Keep your tools in a toolbox designated for hardware troubleshooting. If you put discs and hardware tools in the same box, be sure to keep the discs inside a hard plastic case to protect them from scratches and dents. In addition, make sure the diagnostic and utility software you use is rec- ommended for the hardware and software you are troubleshooting. Now that you’ve prepared your work area and tools, put on your ESD strap—let’s get started with opening the computer case. Step 2: Opening the Case Core 1 Objectives 2.8, 3.1, 3.2, 3.3, 3.4, 3.5 Before we discuss the parts inside a desktop case, let’s take a quick look at the outside of the case and the ports and switches on it. What’s on the Outside of a Desktop Case A computer case for any type of computer is sometimes called Figure 1-6 This slimline tower case supports the chassis, and it houses the power supply, motherboard, pro- a microATX motherboard cessor, memory modules, expansion cards, hard drive, opti- cal drive, and other drives. A computer case can be a tower case, a desktop case that lies flat on a desk, an all-in-one case used with an all-in-one computer, or a mobile case used with laptops and tablets. A tower case (see Figure 1-6) sits upright; it can be as high as two feet and has room for several drives. Often used for servers, this type of case is also good for desk- top computer users who anticipate upgrading because tower cases provide maximum space for working inside a computer and moving components around. A desktop case lies flat and sometimes serves double-duty as a monitor stand. Later in this © Courtesy of IN WIN Development, Inc. module, you learn how to work inside a tower case, desktop case, ­laptop case, and all-in-one case. Note 1 Don’t lay a tower case on its side when the computer is in use because the CD or DVD drive might not work prop- erly. For the same reason, if a desktop case is designed to lie flat, don’t set it on its end when the computer is in use. Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.  Module 1 Taking a Computer Apart and Putting It Back Together 9 Table 1-1 lists ports you might find on a desktop or mobile computer. Consider this table your introduction to these ports so you can recognize them when you see them. Later in the text, you learn more about the details of 1 each port. Exam Tip The A1 Core 1 exam expects you to know how to identify the ports shown in Table 1-1. Table 1-1 Ports used with desktop and laptop computers Port Description A VGA (Video Graphics Array) port—also called a DB-15 port, DB15 port, HD15 port, or DE15 port—is a 15-pin, D-shaped, female port that transmits analog video. (Analog means a continuous signal with infinite variations as compared with digital, which is a series of binary values—1s and 0s.) All older monitors use VGA ports. (By the way, the HD15 [high-definition 15-pin] name for the port is an older name that distinguishes it from the early 9-pin VGA ports.) A DVI (Digital Video Interface) port transmits digital or analog video. You learn about the three types of DVI ports in the module “Supporting I/O Devices.” An HDMI (High-Definition Multimedia Interface) port transmits digital video and audio (not analog transmissions) and is often used to connect to home theater equipment. A DisplayPort transmits digital video and audio (not analog transmissions) and is slowly replacing VGA and DVI ports on personal computers. A Thunderbolt 3 port transmits video, data, and power on the same port and cable and is popular with Apple computers. The port is shaped the Source: Wikimedia same as the USB-C port and is compatible with USB-C devices. Up to six peripherals (for example, monitors and external hard drives daisy-chained together) can use the same Thunderbolt port. Commons A system usually has three or more round audio ports, also called sound ports, for a microphone, audio in, audio out, and stereo audio out. These types of audio ports can transmit analog or digital data. If you have one audio cable to connect to a speaker or earbuds, plug it into the lime green sound port in the middle of the three ports. The microphone uses the pink port. (continues) Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 10 CompTIA A+: Guide to IT Technical Support Table 1-1 Ports used with desktop and laptop computers (Continued) Port Description An SPDIF (Sony-Philips Digital Interface) sound port connects to an external home theater audio system, providing digital audio output and the best signal quality. SPDIF ports always carry digital audio and can work with electrical or optical cable. When connected to a fiber-optic cable, the port is called an optical connector. A USB (Universal Serial Bus) port is a multipurpose I/O port that comes in several sizes and is used by many different devices, including printers, mice, keyboards, scanners, external hard drives, and flash drives. Some USB ports are faster than others. There are several USB standards, with speeds consistently improving with each new release. An external SATA (eSATA) port is used by an external hard drive or other device using the eSATA interface. A PS/2 port, also called a mini-DIN port, is a round 6-pin port used by a keyboard or mouse. The ports look alike but are not interchangeable. On a desktop, the purple port is for the keyboard, and the green port is for the mouse. Most newer computers use USB ports for the keyboard and mouse rather than the older PS/2 ports. An older serial port, sometimes called a DB9 port, is a 9-pin male port used on older computers. It has been mostly replaced by USB ports. Occasionally, you see a serial port on a router, where the port is used to connect the router to a device a technician can use to monitor and manage the router. A modem port, also called an RJ-11 port, is used to connect dial-up phone lines to computers. A modem port looks like a network port but is not as wide. In the photo, the right port is a modem port, and the left port is a network port shown for comparison. A network port, also called an Ethernet port or an RJ-45 port, is used by a network cable to connect to the wired network. Fast Ethernet ports run at 100 Mbps (megabits per second), and Gigabit Ethernet runs at 1000 Mbps or 1 Gbps (gigabits per second). A megabit is one million bits, and a gigabit is one billion bits. A bit is a binary value of 1 or 0. Loopback Plugs A loopback plug is used to test a network port in a computer or other device to make sure the port is working. It might also test the throughput or speed of the port. Figure 1-7 shows a loopback plug testing a network port on a laptop. You know both the port and the network cable are good because the lights on either side of the port are lit. You can also buy a USB loopback plug to test USB ports. Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.  Module 1 Taking a Computer Apart and Putting It Back Together 11 Figure 1-7 A loopback plug testing a network port and network cable 1 What’s Inside a Desktop Case Now that you’re familiar with the outside of the case, let’s open the case to see what is inside. Here are the steps to open a computer case: 1. Back up important data. If you are starting with a working computer, make sure important data is backed up first. Copy the data to an external storage device such as a flash drive or external hard drive. If something goes wrong while you’re working inside the computer, at least your data will be safe. 2. Power down the system and unplug it. Remove discs from the optical drive. Then power down the system, and unplug the power, monitor, mouse, and keyboard cables and any other peripherals or cables attached. Then move these cables out of your way. Caution When you power down a computer and even turn off the power switch on the rear of the computer case, residual power is still on. Some motherboards have a small light inside the case to remind you of this fact and to warn you that power is still getting to the system. Therefore, be sure to always unplug the power cord before opening a case. 3. Press and hold down the power button for a moment. After you unplug the computer, press the power button for about three seconds to completely drain the power supply (see Figure 1-8). Sometimes when you do so, you’ll hear the fans quickly start and go off as residual power is drained. Only then is it safe to work inside the case. Figure 1-8 Press the power button after the computer is unplugged Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 12 CompTIA A+: Guide to IT Technical Support 4. Have a plastic bag or cup handy to hold screws. When you reassemble the computer, you will need to insert the same screws in the same holes. This is especially important with the hard drive because screws that are too long can puncture the hard drive housing, so be careful to label those screws clearly. 5. Open the case cover. Sometimes, figuring out how to open a computer case is the most difficult part of disassembling a computer. If you need help figuring it out, check the user manual or website of the case manufacturer. To remove the computer case cover, do the following: Some cases require you to start by laying the case on its side and removing the faceplate on the front of the case first. Other cases require you to remove a side panel first, and much older cases require you to first remove all the sides and top as a single unit. Study your case for the correct approach. Most cases have panels on each side that can be removed. It is usually necessary to remove only one panel to expose the top of the motherboard. To know which panel to remove, look at the port locations on the rear of the case. For example, in Figure 1-9, the ports on the motherboard are on the left side of the case, indicating the bottom of the motherboard is on the left. Therefore, you will want to remove the right panel to expose the top of the motherboard. Lay the case down to its left so the ports and the motherboard are on the bottom. Later, depending on how drives are installed, it might become necessary to remove the other side panel in order to remove the screws that hold the drives in place. Figure 1-9 Decide which side panel to remove Motherboard is mounted to this side of the case Locate the screws or clips that hold the side panel in place. Be careful not to unscrew any screws besides these. The other screws probably are holding the power supply, fan, and other components in place (see Figure 1-10). Place the screws in the cup or bag used for that purpose. Some cases use clips on a side panel in addition to or instead of screws (see Figure 1-11). Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.  Module 1 Taking a Computer Apart and Putting It Back Together 13 Figure 1-10 Locate the screws that hold the side panel in place 1 Figure 1-11 On this system, clips hold the side panel in place Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 14 CompTIA A+: Guide to IT Technical Support After the screws are removed, slide the panel toward the rear, and then lift it off the case (see Figure 1-12). Figure 1-12 Slide the panel to the rear of the case 6. Clip your ESD strap to the side of the computer case. To dissipate any charge between you and the computer, put on your ESD strap if you have not already done so. Then clip the alligator clip on the strap cable to the side of the computer case (see Figure 1-13). Figure 1-13 Attach the alligator clip of your ground bracelet to the side of the computer case After you open a computer case, as shown in Figure 1-14, the main components you see inside are the power supply, motherboard, expansion card, and drives installed in drive bays. You also see a lot of cables and wires connecting various components. These cables are power cables from the power supply to various components, or cables carrying data and instructions between components. The best way to know the purpose of a cable is to follow it from its source to its destination. Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.  Module 1 Taking a Computer Apart and Putting It Back Together 15 Figure 1-14 Inside the computer case Memory slots 1 Optical (DVD/CD) drive Processor is underneath this fan Front of case Motherboard SATA data cables Two hard drives Solid-state drive Power supply Power cords Here is a quick explanation of the main components installed in the case, which are called internal components: The motherboard, processor, and cooler. The motherboard—also called the main board, the system board, or the techie jargon term, the mobo—is the largest and most important circuit board in the computer. The motherboard contains a socket to hold the processor or CPU. The central processing unit (CPU), also called the processor or microprocessor, does most of the processing of data and instructions for the entire system. Because the CPU generates heat, a fan and heat sink might be installed on top to keep it cool. A heat sink consists of metal fins that draw heat away from a component. The fan and heat sink together are called the processor cooler. Figure 1-15 shows the top view of a motherboard, and Figure 1-16 shows the ports on the side of a motherboard. Figure 1-15 All hardware components are either located on the motherboard or directly or indirectly connected to it because they must all communicate with the CPU PCIe ×16 slot Two PCIe ×1 slots Conventional PCI slot Cooler with CPU below Chipset under heat sink Four memory modules (DIMMs) Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 16 CompTIA A+: Guide to IT Technical Support Figure 1-16 Ports provided by a motherboard eSATA 2.0 port Network port DVI video port FireWire port Six audio ports SPDIF port (for coaxial cable) Two blue USB 3.0 ports HDMI video port DisplayPort video port Six USB 2.0 ports Expansion cards. A motherboard has expansion slots to be used by expansion cards. An expansion card, also called an adapter card, is a circuit board that provides more ports than those provided by the mother- board. Figure 1-17 shows a video card that provides three video ports. Notice the cooling fan and heat sink on the card, which help to keep the card from overheating. The trend today is for most ports in a system to be provided by the motherboard (called onboard ports), with decreased use of expansion cards. Figure 1-17 The easiest way to identify this video card is to look at the ports on the end of the card Cooling fan Heat sink Tab used to stabilize the card PCI Express x16 connector 15-pin analog video port TV-out connector DVI port Memory modules. A desktop motherboard has memory slots, called DIMM (dual inline memory module) slots, to hold memory modules. Figure 1-18 shows a memory module installed in one DIMM slot along with three empty DIMM slots. Memory, also called RAM (random access memory), is temporary storage for data and instructions as they are being processed by the CPU. The memory module shown in Figure 1-18 contains several RAM chips. Video cards also contain some embedded RAM chips for video memory. Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.  Module 1 Taking a Computer Apart and Putting It Back Together 17 Figure 1-18 A DIMM holds RAM and is mounted directly on a motherboard 1 One installed DIMM Three empty DIMM slots Hard drives and other drives. A system might have one or more hard drives and an optical drive. A hard drive, also called a hard disk drive (HDD), is permanent storage used to hold data and programs. For example, the Windows 10 operating system and applications are installed on the hard drive. All drives in a system are installed in a stack of drive bays at the front of the case. The system shown in Figure 1-14 has two hard drives and one optical drive installed. These three drives are also shown in Figure 1-19. The larger hard drive is a magnetic drive, and the smaller hard drive is a solid-state drive (SSD). Each drive has two connections for cables: The power cable connects to the power supply, and another cable, used for data and instructions, connects to the motherboard. Figure 1-19 Two types of hard drives (a larger magnetic drive and a smaller solid-state drive) and a DVD drive 3.5" hard drive 2.5" hard drive DVD drive The power supply. A computer power supply, also known as a power supply unit (PSU), is a box installed in a corner of the computer case (see Figure 1-20) that receives and converts the house cur- rent so components inside the case can use it. Most power supplies have a dual-voltage ­selector switch on the back of the computer case where you can switch the input voltage to the power ­supply if necessary—115 V is used in the United States, and 220 V is used in other countries. See Figure 1-21. The power cables can connect to and supply power to the motherboard, expansion cards, and drives. Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 18 CompTIA A+: Guide to IT Technical Support Figure 1-20 A power supply with attached power cables Power cables Power supply unit Figure 1-21 The dual-voltage selector switch sets the input voltage to the power supply Dual-voltage selector switch Four screws hold the power supply in the case Note 2 If you ever need to change the dual-voltage selector switch, be sure you first turn off the computer and unplug the power supply. Form Factors Used by Desktop Cases, Power Supplies, and Motherboards The desktop computer case, power supply, and motherboard must all be compatible and fit together as an inter- connecting system. The standards that describe the size, shape, screw hole positions, and major features of these interconnected components are called form factors. Using a matching form factor for the motherboard, power ­supply, and case assures you that Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.  Module 1 Taking a Computer Apart and Putting It Back Together 19 The motherboard fits in the case. The power supply cords to the motherboard provide the correct voltage, and the connectors match the 1 connections on the board. The holes in the motherboard align with the holes in the case so you can anchor the board to the case. The holes in the case align with ports coming off the motherboard. For some form factors, wires for switches and lights on the front of the case match up with connections on the motherboard. The holes in the power supply align with holes in the case for anchoring the power supply to the case. The two form factors used by most desktop and tower computer cases and power supplies are the ATX and microATX form factors. Motherboards use these and other form factors that are compatible with ATX or microATX power supplies and cases. You learn about other motherboard form factors in the module “All About Motherboards.” Following are important details about ATX and microATX: ATX (Advanced Technology Extended) is the most commonly used form factor today. It is an open, non- proprietary industry specification originally developed by Intel. An ATX power supply has a variety of power connectors (see Figure 1-22). The power connectors are listed in Table 1-2, and several of them are described next. Figure 1-22 An ATX power supply with connectors 4-pin Molex 6-pin PCIe SATA 8-pin Aux Berg connector 24-pin P1 8-pin PCIe 4-pin Aux Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 20 CompTIA A+: Guide to IT Technical Support Table 1-2 Power supply connector Connector Description The 20-pin P1 connector is the main motherboard power connector used in the early ATX systems. The 24-pin P1 connector, also called the 2014-pin connector, is the main motherboard power connector used today. The 2014-pin P1 connector has four pins removed so the connector can fit into a 20-pin P1 motherboard connector. The 4-pin 12 V connector is an auxiliary motherboard connector, which is used for extra 12 V power to the processor. The 8-pin 12 V connector is an auxiliary motherboard connector, which is used for extra 12 V power to the processor, providing more power than the older 4-pin auxiliary connector. The 4-pin Molex connector is used for older IDE drives and some newer SATA drives, and to provide extra power to video cards. It can provide 15 V and 112 V to the device. The 15-pin SATA power connector is used for SATA (Serial ATA) drives. It can provide 13.3 V, 15 V, and 112 V, although 13.3 V is seldom used. The PCIe 6-pin connector provides an extra 112 V for high-end video cards using PCI Express. The PCIe 8-pin connector provides an extra 112 V for high-end video cards using PCI Express. The PCIe 6/8-pin connector is used by high-end video cards using PCIe 316 slots to provide extra voltage to the card; it can accommodate a 6-hole or 8-hole port. To make the 8-pin connector, combine both the 6-pin and 2-pin connectors. Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.  Module 1 Taking a Computer Apart and Putting It Back Together 21 Power connectors have evolved because compo- Exam Tip nents that use new technologies require more power. 1 The A1 Core 1 exam expects you to know about each As you read about the following types of power con- connector listed in Table 1-2 and to know how to choose nectors and why each came to be, you’ll also learn a ­connector given a scenario. about the evolving expansion slots and expansion cards that drove the need for more power: 4-pin and 8-pin auxiliary connectors. When processors began to require more power, the ATX Version 2.1 specifications added a 4-pin auxiliary connector near the processor socket to provide an additional 12 V of power (see Figure 1-23). A power supply that provides this 4-pin 12 V power cord is called an ATX12V power supply. Later boards replaced the 4-pin 12 V power connector with an 8-pin motherboard auxiliary connector that provided more amps for the processor. See Figure 1-24. Figure 1-23 The 4-pin 12 V auxiliary power connector on a motherboard with a power cord connected Figure 1-24 An 8-pin, 12 V auxiliary power connector for extra power to the processor 8-pin connector Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 22 CompTIA A+: Guide to IT Technical Support 24-pin or 2014-pin P1 connector. The original P1 connector had 20 pins. Later, when faster PCI Express (PCIe) slots were added to motherboards, more power was required and a new ATX specification (ATX ­Version 2.2) allowed for a 24-pin P1 connector, also called the 2014 power connector. All motherboards today use a 24-pin P1 connector. The extra four pins on the 24-pin P1 connector provide 112 volts, 15 volts, and 13.3 volts. Figure 1-25 shows a 24-pin P1 power cord from the power supply and a 24-pin P1 connector on a motherboard. Figure 1-26 shows the pinouts for the 24-pin power cord connector, which is color-coded to wires from the power supply. Figure 1-25 A 24-pin power cord ready to be plugged into a 24-pin P1 connector on an ATX motherboard Figure 1-26 A P1 24-pin power connector follows ATX Version 2.2 and higher standards 1 13 Orange — +3.3V +3.3V — Orange/Brown Orange — +3.3V –12V — Blue Black — COM COM — Black Red — +5V PS_ON# — Green Black — COM COM — Black Red — +5V + COM — Black – Black — COM COM — Black Gray — PWR_ON NC — White Purple — +5VSB +5V — Red Yellow — +12V1 +5V — Red Yellow — +12V1 +5V — Red Orange — +3.3V COM — Black Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.  Module 1 Taking a Computer Apart and Putting It Back Together 23 6-pin and 8-pin PCIe connectors. Video cards draw the most power in a system, and ATX Version 2.2 p ­ rovides for power cables to connect directly to a video card and provide it more power than what comes through 1 the PCIe slot on the motherboard. The PCIe power connector might have six or eight pins. F­ igure 1-27 shows a PCIe 316 video card. The edge connector has a break that fits the break in the slot. The tab at the end of the edge connector fits into a retention mechanism at the end of the slot, which helps to stabilize a heavy video card. The video card has a 6-pin connector on the end of the card. A PCIe 6-pin power cord from the power supply plugs into the connector. The power supply connector is shown earlier in Table 1-2. Figure 1-27 This PCIe 316 video card has a 6-pin PCIe power connector to receive extra power from the power supply PCIe 6-pin power connector on the end of the video card Edge connector Figure 1-28 This microATX motherboard by ASUS is designed The microATX (mATX) form factor is a to support an AMD processor major variation of ATX and addresses some technologies that have emerged since the original development of ATX. MicroATX reduces the total cost of a system by reducing the number of expansion slots on the motherboard, which in turn reduces the power sup- plied to the board and allows for a smaller case size. A microATX moth- erboard (see Figure 1-28) will fit into a case that follows the ATX 2.1 or higher standard. A microATX power supply uses a 24-pin P1 connector and is not likely to have as many extra wires and connectors as those on an ATX power supply. Source: TigerDirect.com Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 24 CompTIA A+: Guide to IT Technical Support Exam Tip The A1 Core 1 exam expects you to recognize and know the more important features of the ATX and microATX form factors used by power supplies. Given a scenario, you should be able to identify and choose the appropriate form factor. Now let’s learn about the expansion cards you might find installed inside a system. Step 3: Removing Expansion Cards Core 1 Objective 3.4 If you plan to remove several components, draw a diagram of all cable connections to the motherboard, expansion cards, and drives. You might need this cable connection diagram to help you reassemble. Note where each cable begins and ends, and pay particular attention to the small wires and connectors that connect the lights, switches, and ports on the front of the case to the motherboard front panel connectors. It’s important to be careful about diagramming these because it is easy to connect them in the wrong position later when you reassemble. You can use a felt-tip marker to make a mark across components, which can indicate a cable connection, board placement, motherboard orientation, speaker connection, brackets, and so on. Then you can simply line up the marks when you reassemble. This method, however, probably won’t work for the front case wires because they are so small. For these, consider writing down the colors of the wires and their positions on the pins or taking a photo of the wires in their positions with your cell phone (see Figure 1-29). Figure 1-29 Diagram the pin locations of the color-coded wires that connect to the front of the case Note 3 A header is a connector on a motherboard that consists of pins that stick up from the board. For example, the group of pins shown in Figure 1-29 is called the front panel header. Computer systems vary in so many ways that it’s impossible to list the exact order to disassemble one. Most likely, however, you need to remove the expansion cards first. Do the following to remove the expansion cards: 1. Remove any wire or cable connected to the card. 2. Remove the screw holding the card to the case (see Figure 1-30). Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.  Module 1 Taking a Computer Apart and Putting It Back Together 25 Figure 1-30 Remove the screw holding the expansion card to the case 1 3. Grasp the card with both hands, and remove it by lifting straight up. If you have trouble removing it from the expansion slot, you can very slightly rock the card from end to end (not side to side). Rocking the card from side to side might spread the slot opening and weaken the connection. 4. As you remove the card, don’t put your fingers on the edge connectors or touch a chip, and don’t stack the cards on top of one another. Lay each card aside on a flat surface, preferably in an antistatic bag. Note 4 Cards installed in PCI Express 3 16 slots use a latch that helps to hold the card securely in the slot. To remove these cards, use one finger to hold the latch back from the slot, as shown in Figure 1-31, as you pull the card up and out of the slot. Figure 1-31 Hold the retention mechanism back as you remove a video card from its expansion slot Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 26 CompTIA A+: Guide to IT Technical Support Step 4: Removing the Motherboard Core 1 Objective 3.4 Depending on the system, you might need to remove the motherboard or the drives next. My choice is to first remove the motherboard. It and the processor are the most expensive and most easily damaged parts of the system. I like to get them out of harm’s way before working with the drives. However, in some cases, you must remove the drives or the power supply before you can get to the motherboard. Study your situation and decide which to do first. To remove the motherboard, do the following: 1. Unplug the power supply lines to the motherboard. 2. Unplug SATA cables connected to the motherboard. 3. Disconnect the wires leading from the front or top of the computer case to the motherboard; these wires are called the front panel connectors. If you don’t have the motherboard manual handy, be very careful to diagram how these wires connect because they are rarely labeled well on a motherboard. Make a careful diagram, and then disconnect the wires. Figure 1-32 shows five leads and the pins on the motherboard front panel header that receive these leads. The pins are color-coded and cryptically labeled on the board. Figure 1-32 Five leads from the front panel connect to two rows of pins on the motherboard front panel header 4. Disconnect any other cables or wires connected to the motherboard. A case fan might be getting power by a small wire connected to the motherboard. In addition, USB ports on the front of the computer case might be connected by a cable to the motherboard. 5. You’re now ready to remove the screws that hold the motherboard to the case. A motherboard is installed so that the bottom of the board does not touch the case. If the fine traces or lines on the bottom of the board were to touch the case, a short would result when the system runs again. To keep the board from touching the case, screw holes are elevated using spacers, also called standoffs, which are round plastic or metal pegs that separate the board from the case. Carefully pop off these spacers and/or remove the screws (up to nine) that hold the board to the case (see Figure 1-33) and then remove the board. Set it aside in a safe place. Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.  Module 1 Taking a Computer Apart and Putting It Back Together 27 Figure 1-33 Remove up to nine screws that hold the motherboard to the case 1 Figure 1-34 shows a motherboard sitting to the side of these spacers. Two spacers are in place, and the other is lying beside its case hole. In the figure, also notice the holes in the motherboard where screws are used to connect the board to the spacers. Figure 1-34 This motherboard connects to a case using screws and spacers that keep the board from touching the case Holes in motherboard Spacers Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 28 CompTIA A+: Guide to IT Technical Support Note 5 When you’re replacing a motherboard that is not the same size as the original board in a case, you can use needle-nose pliers to unplug a standoff so you can move it to a new hole. 6. The motherboard should now be free, and you can carefully remove it from the case, as shown in Figure 1-35. Lift the board by its edges, as shown in the figure. Figure 1-35 Remove the motherboard from the case Caution Never lift a motherboard by the cooler because doing so might create an air gap between the cooler and the processor, which can cause the processor to overheat later. Caution Some processors have heavy or bulky cooling assemblies installed on top of them. For these systems, it is best to remove the cooler before you take the motherboard out of the case because the motherboard is not designed to sup- port the heavy cooler when the motherboard is not securely seated in the case. Removal of the cooler is covered in the module “Supporting Processors and Upgrading Memory.” POST Diagnostic Cards When supporting a motherboard, a POST diagnostic card, also called a POST card or motherboard test card, can be of great help in discovering and reporting computer errors and conflicts that occur after you first turn on a computer but before the operating system (such as Windows 10) is launched. To understand what a POST card does, you need to know about the firmware—the programs and data stored on the motherboard. Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.  Module 1 Taking a Computer Apart and Putting It Back Together 29 Firmware consists of the older BIOS (basic input/output system) firmware and the newer UEFI (Unified ­Extensible Firmware Interface) firmware and is usually referred to as BIOS or UEFI. Figure 1-36 shows an embed- 1 ded firmware chip on a motherboard that contains the BIOS/UEFI programs. BIOS/UEFI is responsible for managing essential devices (for example, keyboard, mouse, hard drive, and monitor) before the OS is launched, starting the computer, and managing motherboard settings. A feature of the newer UEFI is that it can manage a secure boot, assuring that no rogue malware or operating system hijacks the system during the boot. Figure 1-36 This firmware chip contains BIOS/UEFI, flash ROM, and CMOS RAM; CMOS RAM is powered by the coin battery located near the chip Coin battery Firmware chip A POST card is not essential, but it can be quite useful. The POST (power-on self-test) is a series of tests per- formed by the startup BIOS/UEFI when you first turn on a computer. These tests determine if the startup BIOS/ UEFI can communicate correctly with essential hardware components required for a successful boot. If you have a problem that prevents the computer from booting and that you suspect is related to hardware, you can install the POST card in an expansion slot on the motherboard. For laptops, some cards install in a USB port. You can then attempt to boot. The card monitors the boot process and reports errors, usually as coded numbers on a small LED panel on the card. You then look up the number online or in the documentation that accompanies the card to get more information about the error and its source. Figure 1-37 shows a POST diagnostic card, the Post Code Master card by Microsystems Developments, Inc. Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 30 CompTIA A+: Guide to IT Technical Support Figure 1-37 The Post Code Master diagnostic card by Microsystems Developments, Inc., installs in a PCI slot Before purchasing this or any other diagnostic tools or software, read the documentation about what they can and cannot do, and read some online product reviews. Try using google.com and searching on “computer diagnostic card reviews.” Note 6 Some Dell computers have lights on the case that blink in patterns to indicate a problem early in the boot before the OS loads. These blinking lights give information similar to that given by POST cards. Step 5: Removing the Power Supply Core 1 Objective 3.5 To remove the power supply from the case, look for screws that attach the power supply to the computer case, as shown in Figure 1-38. Be careful not to remove any screws that hold the power supply housing together. You do not want to take the housing apart. After you have removed the screws, the power supply still might not be free. Sometimes, it is attached to the underside of the case by recessed slots. Turn the case over, and look on the bottom for these slots. If they are present, determine in which direction you need to slide the power supply to free it from the case. Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.  Module 1 Taking a Computer Apart and Putting It Back Together 31 Figure 1-38 Remove the power supply mounting screws 1 Power Supply Tester A power supply tester is used to measure the output of each connector coming from the power supply. You can test the power supply when it is outside or inside the case. As you saw earlier in Figure 1-20, the power supply provides several cables and connectors that power various components inside the computer case. A power supply tester has plugs for each type of cable. Connect a power cable to the tester, plug up the power supply, and turn on the tester. An LCD panel reports the output of each lead (see Figure 1-39). Figure 1-39 Use a power supply tester to test the output of each power connector on a power supply Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 32 CompTIA A+: Guide to IT Technical Support Multimeter A multimeter (see Figure 1-40) is a more general-purpose tool that can measure several characteristics of electric- ity in a variety of devices. Some multimeters can measure voltage, current, resistance, and continuity. (Continuity determines that two ends of a cable or fuse are connected without interruption.) When set to measure voltage, you can use it to measure output of each pin on a power supply connector. When set to measure continuity, a multimeter is useful to test fuses, to determine if a cable is good, or to match pins on one end of a cable to pins on the other end. Figure 1-40 This digital multimeter can be set to measure voltage, resistance, or continuity To measure DC voltage Data hold switch Install the red probe at the positive (+) jack on the meter Install the black probe at the negative (–) jack on the meter To measure AC voltage To measure resistance To measure continuity Function switch Step 6: Removing the Drives Core 1 Objective 3.3 A computer might have one or more hard drives, an optical drive (CD, DVD, or Blu-ray), or some other type of drive. A drive receives power by a power cable from the power supply and communicates instructions and data through a cable attached to the motherboard. Most hard drives and optical drives today use the serial ATA (SATA) standard. Figure 1-41 shows a SATA cable connecting a hard drive and motherboard. SATA cables can only connect to a SATA connector on the motherboard in one direction (see Figure 1-42). SATA drives get their power from a power cable that connects to the drive using a SATA power connector (refer back to the photo in Table 1-2). Copyright 2023 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.  Module 1 Taking a Computer Apart and Putting It Back Together 33 Figure 1-41 A hard drive subsystem using the SATA data cable 1