POST (3.1.1.2)

When a computer is booted, the basic input/output system (BIOS) performs a hardware check on the main components of the computer. This check is called a power-on self-test (POST).

For instance, Figure 3-1 displays a screen capture of a sample POST being performed. Notice that the computer checks whether the computer hardware is operating correctly.

If a device is malfunctioning, an error code or beep code alerts the technician of the problem. If there is a hardware problem, a blank screen might appear at bootup, and the computer may emit a series of beeps.

BIOS manufacturers use different codes to indicate hardware problems. Table 3-1 shows a chart of common beep codes. However, motherboard manufacturers may use different beep codes. Always consult the motherboard documentation to get the beep codes for your computer.

BIOS and CMOS (3.1.1.3)

All motherboards need BIOS to operate. BIOS is a ROM chip on the motherboard that contains a small program. This program controls the communication between the operating system and the hardware.

Along with the POST, BIOS also identifies the following:

• Which drives are available

• Which drives are bootable

• How the memory is configured and when it can be used

• How PCIe and PCI expansion slots are configured

• How SATA and USB ports are configured

• Motherboard power management features

The motherboard manufacturer saves the motherboard BIOS settings in a CMOS memory chip such as the one shown in Figure 3-2.

When a computer boots, the BIOS software reads the configured settings stored in CMOS to determine how to configure the hardware.

The BIOS settings are retained by CMOS using a battery, such as the one shown in Figure 3-3. However, if the battery fails, important settings can be lost. Therefore, it is recommended that BIOS settings be documented.

UEFI (3.1.1.4)

Most computers today run UEFI. Figure 3-4 shows an example.

All new computers come with UEFI, which provides additional features and addresses security issues with legacy BIOS. You might see “BIOS/UEFI” when booting into your BIOS settings. This is because Intel chips currently support backward compatibility with legacy BIOS systems. However, by 2020, Intel will end support for legacy BIOS. For more information, do an Internet search for “Intel to remove legacy BIOS.”

UEFI includes the same settings as traditional BIOS but also provides additional options. For example, UEFI can provide a mouse-enabled software interface instead of the traditional BIOS screens. However, most systems have a text-based interface, similar to legacy BIOS systems.

UEFI can run on 32-bit and 64-bit systems, supports larger boot drives, and includes additional features, such as secure boot. Secure boot ensures that your computer boots to your specified operating system. This helps prevent rootkits from taking over the system. For more information, do an Internet search for “Secure boot and rootkits.”

BIOS and UEFI Security (3.1.2.2)

The legacy BIOS supports some security features to protect the BIOS setting. UEFI adds additional security features. These are some common security features found in the BIOS/UEFI systems:

• Passwords: Passwords allow for different levels of access to the BIOS settings. Usually, there are two password settings that can be altered: the supervisor password and the user password. The supervisor password can access all user-access passwords and all BIOS screens and settings. The user password gives access to the BIOS based on a defined level. Table 3-2 lists common levels of user access to BIOS. The supervisor password must be set before the user password can be configured.

• Drive encryption: A hard drive can be encrypted to prevent data theft. Encryption changes the data on the drive into code. Without the correct password, the computer cannot boot, and data read from the hard drive cannot be understood. Even if the hard drive is placed in another computer, the data remains encrypted.

• LoJack: This is a security feature that consists of two programs: the persistence module and the application agent. The persistence module is embedded in the BIOS, and the application agent is installed by the user. When installed, the persistence module in the BIOS is activated and cannot be turned off. The application agent routinely contacts a monitoring center over the Internet to report device information and location. The owner can perform the following functions:

  • Locate the device using Wi-Fi or IP geolocation to see the last location.

  • Lock the device remotely to prevent access to personal information. Display a customized message on the screen.

  • Delete all files on the device to protect personal information and prevent identity theft.

• Trusted Platform Module (TPM): This is a chip designed to secure hardware by storing encryption keys, digital certificates, passwords, and data. TPM is used by Windows to support BitLocker full-disk encryption.

• Secure boot: Secure boot is a UEFI security standard which ensures that a computer only boots an OS that is trusted by the motherboard manufacturer. Secure boot prevents an “unauthorized” OS from loading during startup.

Update the Firmware (3.1.2.3)

Motherboard manufacturers may publish updated BIOS versions to provide enhancements to system stability, compatibility, and performance. However, updating the firmware is risky. The release notes, such as those shown in Figure 3-5, describe the upgrade to the product, compatibility improvements, and the known bugs that have been addressed. Some newer devices operate properly only with an updated BIOS version installed. You can usually find the current version on the main screen of the BIOS/UEFI interface.

Before updating motherboard firmware, record the manufacturer of the BIOS and the motherboard model. Use this information to identify the exact files to download from the motherboard manufacturer’s site. Update the firmware only if there are problems with the system hardware or to add functionality to the system.

Early computer BIOS information was contained in ROM chips. To upgrade the BIOS information, the ROM chip had to be physically replaced, which was not always possible. Modern BIOS chips are electrically erasable programmable read-only memory (EEPROM), which the user can upgrade without opening the computer case. This process is called flashing the BIOS.

To download a new BIOS, consult the manufacturer’s website and follow the recommended installation procedures. Installing BIOS software online may involve downloading a new BIOS file, copying or extracting files to removable media, and then booting from the removable media. An installation program prompts the user for information to complete the process.

Many motherboard manufacturers now provide software to flash the BIOS from within an operating system. For example, the ASUS EZ Update utility automatically updates a motherboard’s software, drivers, and the BIOS version. It also enables a user to manually update a saved BIOS and select a boot logo when the system goes into POST. The utility is included with the motherboard, or it can be downloaded from the ASUS website.

Wattage and Voltage (3.2.1.1)

Power supply specifications are typically expressed in watts (W). To understand what a watt is, refer to the interactive image in the online course, which describes the four basic units of electricity that a computer technician must know.

The basic equation known as Ohm’s law indicates that voltage is equal to the current multiplied by the resistance: V = IR. In an electrical system, power is equal to the voltage multiplied by the current: P = VI. The following are definitions of power-related terminology:

• Voltage, measured in volts (V)

  • This is a measure of work required to move a charge from one location to another.

  • A computer power supply usually produces several different voltages.

• Resistance, measured in Ohms (O)

  • This refers to the opposition to the flow of current in a circuit.

  • Lower resistance allows more current to flow through a circuit.

  • A good fuse has low resistance, or almost 0 ohms.

• Current, measured in amperes, or amps (A)

  • This is a measure of the number of electrons moving through a circuit per second.

  • Computer power supplies deliver different amperages for each output voltage.

• Power, measured in watts (W)

  • This is a measure of the work required to move electrons through a circuit (voltage), multiplied by the number of electrons going through that circuit per second (current).

  • Computer power supplies are rated in watts.

Power Supply Voltage Setting (3.2.1.2)

On the back of some power supplies is a small switch called the voltage selector switch, as shown in Figure 3-6.

This switch sets the input voltage to the power supply to either 110V/115V or 220V/230V. A power supply with this switch is called a dual voltage power supply. The correct voltage setting depends on the country where the power supply is used. Setting the voltage switch to the incorrect input voltage could damage the power supply and other parts of the computer. If a power supply does not have this switch, it automatically detects and sets the correct voltage.

For more information about power supplies, refer to https://www.newegg.com/insider/how-to-choose-a-pc-power-supply-buying-guide/.

Power Fluctuation Types (3.2.2.1)

Voltage is a measure of energy required to move a charge from one location to another. The movement of electrons is called current. Computer circuits need voltage and current to operate electronic components. When the voltage in a computer is not accurate or steady, computer components might not operate correctly. Unsteady voltages are called power fluctuations.

The following types of AC power fluctuations can cause data loss or hardware failure:

• Blackout: Complete loss of AC power. A blown fuse, damaged transformer, or downed power line can cause a blackout.

• Brownout: A reduced voltage level of AC power that lasts for a period of time. Brownouts occur when the power line voltage drops below 80% of the normal voltage level and when electrical circuits are overloaded.

• Noise: Interference from generators and lightning. Noise results in poor-quality power, which can cause errors in a computer system.

• Spike: A sudden increase in voltage that lasts for a short period and exceeds 100% of the normal voltage on a line. Spikes can be caused by lightning strikes but can also occur when the electrical system comes back on after a blackout.

• Power surge: A dramatic increase in voltage above the normal flow of electrical current. A power surge lasts for a few nanoseconds, or one-billionth of a second.

Power Protection Devices (3.2.2.2)

To help shield against power fluctuation problems, use devices to protect the data and computer equipment:

• Surge protector: Helps protect against damage from surges and spikes. A surge suppressor diverts extra electrical voltage that is on the line to the ground. The amount of protection offered by a surge protector is measured in joules. The higher the joule rating, the more energy the surge protector can absorb over time. Once the number of joules is reached, the surge protector no longer provides protection and needs to be replaced.

• Uninterruptible power supply (UPS): Helps protect against potential electrical power problems by supplying a consistent level of electrical power to a computer or other device. The battery is constantly recharging while the UPS is in use. The UPS provides a consistent quality of power when brownouts and blackouts occur. Many UPS devices can communicate directly with the computer operating system. This communication allows the UPS to safely shut down the computer and save data prior to the UPS losing all battery power.

• Standby power supply (SPS): Helps protect against potential electrical power problems by providing a backup battery to supply power when the incoming voltage drops below the normal level. The battery is on standby during normal operation. When the voltage decreases, the battery provides DC power to a power inverter, which converts it to AC power for the computer. This device is not as reliable as a UPS because of the time it takes to switch over to the battery. If the switching device fails, the battery cannot supply power to the computer.

CPU Architectures (3.3.1.1)

A program is a sequence of stored instructions. A CPU executes these instructions by following a specific instruction set.

CPUs may use two distinct types of instruction sets:

• Reduced Instruction Set Computer (RISC): This architecture uses a relatively small set of instructions. RISC chips are designed to execute these instructions very rapidly. Some well-known CPUs using RISC are PowerPC and ARM.

• Complex Instruction Set Computer (CISC): This architecture uses a broad set of instructions, resulting in fewer steps per operation. Intel x86 and Motorola 68k are some well-known CPUs using CISC.

While the CPU is executing one step of a program, the remaining instructions and the data are stored nearby in a special high-speed memory, called cache.

Enhancing CPU Operation (3.3.1.2)

Various CPU manufacturers complement their CPUs with performance-enhancing features. For instance, Intel incorporates Hyper-Threading to enhance the performance of some of its CPUs. With Hyper-Threading, multiple pieces of code (threads) are executed simultaneously in the CPU. To an operating system, a single CPU with Hyper-Threading performs as though there are two CPUs when multiple threads are being processed. AMD processors use HyperTransport to enhance CPU performance. HyperTransport is a high-speed connection between the CPU and the Northbridge chip.

The power of a CPU is measured by the speed and the amount of data that it can process. The speed of a CPU is rated in cycles per second, such as millions of cycles per second, called megahertz (MHz), or billions of cycles per second, called gigahertz (GHz). The amount of data that a CPU can process at one time depends on the size of the front-side bus (FSB). This is also called the CPU bus or the processor data bus. Higher performance can be achieved when the width of the FSB increases, much as a roadway can carry more cars when it has many lanes. The width of the FSB is measured in bits. A bit is the smallest unit of data in a computer. Current processors use a 32-bit or 64-bit FSB.

Overclocking is a technique used to make a processor work at a faster speed than its original specification. Overclocking is not a recommended way to improve computer performance and can result in damage to the CPU. The opposite of overclocking is CPU throttling. CPU throttling is a technique used when the processor runs at less than the rated speed to conserve power or produce less heat. Throttling is commonly used on laptops and other mobile devices.

CPU virtualization is a hardware feature supported by AMD and Intel CPUs that enables a single processor to act as multiple processors. This hardware virtualization technology allows the operating system to support virtualization more effectively and efficiently than is possible through software emulation. With CPU virtualization, multiple operating systems can run in parallel on their own virtual machines as if they were running on completely independent computers. CPU virtualization is sometimes disabled by default in the BIOS and needs to be enabled.

Multicore Processors (3.3.1.3)

CPU manufacturers have found ways to incorporate more than one CPU core into a single chip. A multicore CPU has two or more processors on the same integrated circuit. In some architectures, the cores have separate L2 and L3 cache resources, while in other architectures, cache is shared among the different cores for better performance and resource allocation. Table 3-3 describes the various types of multicore processors.

Integrating the processors on the same chip creates a very fast connection between them. Multicore processors execute instructions more quickly than do single-core processors. Instructions can be distributed to all the processors at the same time. RAM is shared between the processors because the cores reside on the same chip. A multicore processor is recommended for applications such as video editing, gaming, and photo manipulation.

High power consumption creates more heat in the computer case. Multicore processors conserve power and produce less heat than multiple single-core processors, thus increasing performance and efficiency.

Another feature found in some CPUs is an integrated graphics processing unit (GPU). The GPU is a chip that performs the rapid mathematical calculations required to render graphics. A GPU can be integrated or dedicated. Integrated GPUs are often directly embedded on the CPU and are dependent on system RAM; a dedicated GPU is a separate chip with its own video memory dedicated exclusively to graphical processing. The benefit of integrated GPUs is cost and less heat dissipation. They make it possible to create less expensive computers and smaller form factors. The trade-off is performance. Integrated GPUs are good for less complex tasks such as playing videos and processing graphical documents but are not best suited for intense gaming applications.

CPUs have also been enhanced using the execute disable (NX) bit. This feature, when supported and enabled in the operating system, can protect areas of memory that contain operating system files from malicious attacks by malware.

CPU Cooling Mechanisms (3.3.1.4)

Several mechanisms are used to cool a computer:

• Case fan: Increasing the air flow in the computer case allows more heat to be removed. An active cooling solution uses fans inside a computer case, as shown in Figure 3-7, to blow out hot air. For increased air flow, some cases have multiple fans to bring in cool air and also blow out hot air.

• CPU heat sink: The CPU generates a lot of heat inside the case. To draw heat away from the CPU core, a heat sink (see Figure 3-8) is installed on top of it. The heat sink has a large surface area with metal fins to dissipate heat into the surrounding air. This is known as passive cooling. Between the heat sink and the CPU is a special thermal compound, which increases the efficiency of heat transfer from the CPU to the heat sink by filling any tiny gaps between the two.

• CPU fan: CPUs that are overclocked or running multiple cores tend to generate excessive heat. It is a very common practice to install a fan (see Figure 3-9) on top of the heat sink. The fan moves heat away from the metal fins of the heatsink. This is known as active cooling.

• Graphics card cooling system: Other components are also susceptible to heat damage and are often equipped with fans. Video adapter cards have their own processor, called a graphics processing unit (GPU), which generates excessive heat. Video adapter cards also come equipped with one or more fans, as shown in Figure 3-10.

• Water cooling system: Computers with extremely fast CPUs and GPUs might use a water-cooling system like the one shown in Figure 3-11. A metal plate is placed over the processor, and water is pumped over the top to collect the heat that the processor generates. The water is pumped to a radiator to disperse the heat into the air, and the water is then recirculated. CPU fans make noise and can be annoying at high speeds. An alternative to cooling a CPU with a fan is a method that uses heat pipes. A heat pipe contains liquid that is permanently sealed at the factory and uses a system of cyclical evaporation and condensation.

What Do You Already Know? - RAID (3.3.2.1)

What do you already know about RAID? These are the RAID characteristics:

• Availability

• Capacity

• Economy

• Performance

• Redundancy

• Reliability

RAID Concepts (3.3.2.2)

With RAID, storage devices can be grouped and managed to create large storage volumes with redundancy. RAID provides a way to store data across multiple storage devices for availability, reliability, capacity, and redundancy and/or performance improvement. In addition, it may be more economical to create an array of smaller devices than it is to purchase a single device with the combined capacity provided by the RAID, especially for very large drives. To the operating system, a RAID array appears as one drive.

The following terms describe how RAID stores data on the various disks:

• Striping: This RAID type enables data to be distributed across multiple drives, which provides a significant performance increase. However, because the data is distributed across multiple drives, the failure of a single drive means that all data is lost.

• Mirroring: This RAID type stores duplicate data on one or more other drives. This provides redundancy so that the failure of a drive does not cause the loss of data. The mirror can be re-created by replacing the drive and restoring the data from the good drive.

• Parity: This RAID type provides basic error checking and fault tolerance by storing checksums separately from data. This enables the reconstruction of lost data without sacrificing speed and capacity, which is a problem with mirroring.

• Double parity: This RAID type provides fault tolerance for up to two failed drives.

A large drive enclosure can be used in a data center with one or more RAID implementations. Drive enclosures are specialized enclosures designed to hold and provide power to disk drives while allowing the drives within to communicate to one or more separate computers. Drive enclosures can use hot swappable drives. This means that a drive that fails can be replaced without powering down the entire RAID. Powering down the RAID may make the data on the RAID unavailable to users for an extended period of time. Not all drives and RAID types support hot swapping.

RAID Levels (3.3.2.3)

There are several levels of RAID available. These levels use mirroring, striping, and parity in different ways. Higher levels of RAID, such as RAID 5 or 6, use striping and parity in combination to provide speed and to create large volumes. Table 3-4 provides details about the RAID levels. RAID levels from 10 up combine lower RAID levels. For example, RAID 10 combines RAID 1 and RAID 0 functionalities.

Legacy Ports (3.3.3.1)

Computers have many different types of ports used to connect external peripheral devices. As computer technology has evolved, so have the types of ports used to connect peripheral devices. Legacy ports are typically found on older computers and have been mostly replaced by newer technologies such as USB. The sections that follow describes the various legacy ports.

Serial Ports

Serial ports were used to connect various peripherals such as printers, scanners, and modems. Today, serial ports are sometimes used for making console connections to network devices to perform initial configuration. There are two form factors of serial ports: a 9-pin DB-9 port and a 25-pin port. Figure 3-12 shows a 9-pin DB-9 port.

Parallel Ports

A parallel ports has a 25-pin receptacle used to connect various peripheral devices, as shown in Figure 3-13. As the name implies, parallel ports send data in multiple bits at once, in parallel communication. Because these ports were often used to connect printers, they are often called printer ports.

Game Ports

The 15-pin game port (see Figure 3-14) was used as a connector for joystick input. Game ports were originally located on a dedicated game controller expansion card and then later integrated with sound cards and on PC motherboards.

PS/2 Ports

The PS/2 is a 6-pin din connector used for connecting a keyboard and mouse. Figure 3-15 shows two color-coded PS/2 ports: purple for the keyboard and green for the mouse.

Audio Ports

Audio ports (see Figure 3-16) connect audio devices to the computer. Analog ports typically include a line in port to connect to an external source (for example, a stereo system), a microphone port, and line out ports to connect speakers or headphones.

Video and Graphic Ports (3.3.3.2)

Graphic ports are used to connect monitors and external video displays to desktop computers and laptops. The sections that follow describe these ports in greater detail.

VGA Ports

A VGA port (see Figure 3-17) is an analog port and is the oldest graphics port likely still used on some PCs, although it is quickly becoming a legacy technology. A VGA port is colored blue and accepts a 15-pin connector, with the pins arranged in three rows.

DVI Ports

The emergence of digital displays such as LCD monitors and TVs led to the development of DVI for transmitting uncompressed digital video. Variants of the DVI interface are configured to support multiple transmission modes. DVI-A (analog) supports analog only, DVI-D (digital) supports digital only, and DVI-I (integrated) supports both digital and analog. Figure 3-18 shows DVI-I. Two forms of DVI connections exist:

• Single-link connections that use a single Transition Minimized Differential Signaling (TMDS) transmitter

• Dual-link connections that use two TMDS transmitters to provide higher resolutions to larger monitors

HDMI Ports

HDMI (see Figure 3-19) carries the same video information as DVI but is also capable of providing digital audio and control signals. HDMI uses a 19-pin connector. Smaller portable electronic devices have a smaller 19-pin mini-HDMI port.

DisplayPort

DisplayPort (see Figure 3-20) is a newer technology designed to replace both DVI and VGA for connecting computer monitors. DisplayPort uses a 20-pin connector for delivering high-bandwidth video and audio signals. As with HDMI, there is a miniaturized version of DisplayPort called Mini DisplayPort; it is primarily used on Apple computers.

USB Cables and Connectors (3.3.3.3)

The USB protocol has evolved over the years, and the various standards can be confusing. USB 1.0 provided a low-speed transfer rate at 1.5 Mbps for keyboards and mice and a full-speed channel at 12 Mbps. USB 2.0 made a significant leap, increasing transfer rates up to High Speed at 480 Mbps. USB 3.0 increased the transfer rate to SuperSpeed, at 5 Gbps, and USB 3.2, the latest USB-C specification, supports speeds of up to SuperSpeed+, or 20 Gbps. The sections that follow describe and show the various USB cables and connectors.

USB Type-A

USB Type-A, shown in Figure 3-21, is a rectangular connector found on nearly every desktop PC and laptop, as well as TVs, game consoles, and media players. USB 1.1, 2.0, and 3.0 Type-A connectors and receptacles are physically compatible.

USB Mini-B

The USB Mini-B connector, shown in Figure 3-22, is rectangular with a small indention on each side. The USB Mini-B, also known as mini-USB, form factor is being phased out and replaced by the micro-USB connector.

Micro-USB

The micro-USB connector, shown in Figure 3-23, is found on smartphones, tablets, and other devices. Except for Apple, most manufacturers have adopted the micro-USB interface. The USB 2.0 Micro-B connector has two corners pushed in at an angle.

USB Type-B

The USB Type-B connector, shown in Figure 3-24, is commonly used to connect printer and external hard drives. It has a square shape with beveled exterior corners and an extra notch at the top.

USB Type-C

USB Type-C, shown in Figure 3-25, is the newest USB interface. A USB Type-C connector is smaller than a Type-A connector and is rectangular, with four rounded corners. Both Thunderbolt 3 and USB Type-C are examples of multipurpose cables that can be used to attach different kinds of peripheral devices to a PC. USB Type-C refers to the shape of the port. Thunderbolt 3 combines the functionality of USB, Thunderbolt, and DisplayPort, and it provides the ability to deliver power to devices through the cable.

Lightning

The Lightning connector, shown in Figure 3-26, is a small, proprietary 8-pin connector used by Apple mobile devices such as iPhones, iPads, and iPods for both power charging and data transfer. It is similar in appearance to a USB Type-C connector.

SATA Cables and Connectors (3.3.3.4)

SATA is an interface type used to connect SATA hard drives and other storage devices to the motherboard inside the computer. SATA cables are long (up to 1 meter) and thin, with a flat and thin 7-pin connector on each end. The sections that follow describe the characteristics and types of SATA cables and connectors.

SATA Cables and Connectors

Figure 3-27 shows a SATA cable. One end plugs into a SATA port on the motherboard, and the other end plugs into the back of an internal storage device such as a SATA hard drive. The SATA connecter has an L-shaped key so that it can be installed only one way.

SATA Data and Power Cables

A SATA data cable does not provide power, and an additional cable is needed to supply power to SATA drives, as shown in Figure 3-28.

eSATA Cables

An eSATA cable, shown in Figure 3-29, is used to connect an external SATA drive. Unlike a SATA connector, an eSATA connector does not have an L-shaped key. However, an eSATA port does have a key feature to prevent inadvertent insertion of a USB connector, which is similar in size and shape.

eSATA Adapter Card

Often, an eSATA adapter card (see Figure 3-30) is installed in a computer to provide eSATA ports.

Twisted Pair Cables and Connectors (3.3.3.5)

Twisted pair cable is used in wired Ethernet networks and in older telephone networks. Twisted pair cabling gets its name from the fact that pairs of wires inside the cable are twisted together. The twisting of wire pairs helps reduce crosstalk and electromagnetic induction. The sections that follow describe the characteristics and types of twisted pair cables and connectors.

RJ-45 Connectors

Each end of a UTP cable must be terminated with a connector. In the case of Ethernet networks, an RJ-45 connector (see Figure 3-31) terminates the cable and is plugged into an Ethernet port.

RJ-11 Connectors

Older telephone networks used a four-wire UTP cable with two wire pairs terminated with a 6-pin RJ-11 connector, shown in Figure 3-32. The RJ-11 connector looks very similar to the RJ-45 connector but is smaller.

Coax Cables and Connectors (3.3.3.6)

Coaxial (coax) cable has an inner center conductor, usually made from copper or copper-clad steel, which is surrounded by a nonconductive dielectric insulating material. The dielectric is surrounded by a foil shield, which forms the outer conductor and shields against electromagnetic interference (EMI). The outer conductor/shield is encased in a PVC outer jacket. The sections that follow describe the characteristics and types of coax cables and connectors.

Coax Cable Construction

The coax cable in Figure 3-33 has the outer jacket pulled back to reveal the braided shielding and copper core conductor.

RG-6

An RG-6 cable (see Figure 3-34) cable is heavy gauge and has insulation and shielding tuned for high-bandwidth, high-frequency applications such as Internet, cable TV, and satellite TV signals.

RG-59

RG-59 cable is thinner and is recommended in low-bandwidth and lower-frequency applications, such as analog video and CCTV applications, such as for the camera in Figure 3-35.

BNC

A BNC (Bayonet Neill–Concelman) connector, shown in Figure 3-36, connects coaxial cables to devices using a quarter-turn connection scheme. BNC is used with digital or analog audio or video.

SCSI and IDE Cables and Connectors (3.3.3.7)

Small Computer System Interface (SCSI) is a standard for connecting peripheral and storage devices. SCSI is a bus technology, meaning that all devices connect to a central bus and are “daisy-chained” together. The cabling/connector requirements depend on the location of the SCSI bus.

Integrated Drive Electronics (IDE) is a standard type of interface used to connect some hard drives and optical drives to each other and to the motherboard.

The sections that follow describe the characteristics and types of SCSI and IDE cables and connectors.

External SCSI Cables

A Centronics connector (see Figure 3-37) is used for connecting older external SCSI devices such as scanners and printers. This connector comes in 36-pin and 50-pin versions, with the pins arranged in two rows and a plastic bar through the center that holds the contact pins. Squeeze latches or bail locks located on the sides of the connector are used to hold it in place.

Internal SCSI Cables

A common SCSI connector for internal hard drives is the internal 50-pin SCSI, which has 50 pins arranged in two rows and is attached to a ribbon cable, as shown in Figure 3-38.

IDE Cables

IDE ribbon cables, shown in Figure 3-39, look very similar to internal SCSI cables; however, IDE uses 40-pin connectors. There are typically three connectors on the cable: one to connect to the IDE port on the motherboard and two for attachment of IDE drives.

Check Your Understanding 3.3.3.8: Identify the External Connectors

Refer to the online course to complete this activity.

Monitor Characteristics (3.3.4.1)

There are many types of computer monitors available. Some are designed for casual use, and others are for specific requirements, such as those used by architects, graphic designers, or gamers.

Monitors vary by use, size, quality, clarity, brightness, and other factors. Therefore, it is useful to understand the various terms used when discussing monitors.

Computer monitors are usually described in terms of the following:

• Screen size: This is the diagonal measurement of the screen (such as from top left to bottom right), in inches. Common sizes include 19 to 24 inches, to ultrawide monitors that are 30 or more inches wide. Larger monitors are usually better but are more expensive and require more desk space.

• Resolution: Resolution is measured by the number of horizontal and vertical pixels. For example, 1920×1080 (called 1080p) is a common resolution. It means the monitor has 1920 horizontal pixels and 1080 vertical pixels.

• Monitor resolution: This relates to the amount of information that can be displayed on a screen. A higher-resolution monitor displays more information on a screen than a lower-resolution monitor does. This is true even with monitors that have the same screen size.

• Native resolution: This identifies the best monitor resolution for the specific monitor. In Windows 10, the native resolution of a monitor is identified by the keyword (Recommended) beside the monitor resolution. For example, in Figure 3-40, the native resolution of the monitor is 1920×1080.

• Native mode: This term describes the image sent to the monitor by the video adapter card matching the native resolution of the monitor.

• Connectivity: Older monitors used VGA or DVI connectors, and newer monitors support HDMI and DisplayPort ports. DisplayPort is a connection found on newer monitors. It supports higher resolutions and high refresh rates.

Monitor Terms (3.3.4.2)

Table 3-5 lists the most common monitor-related terms.

Display Standards (3.3.4.3)

Over the years, many different display standards have been developed, as shown in Table 3-6.

Using Multiple Monitors (3.3.4.4)

Adding monitors can increase your visual desktop area and improve productivity. The added monitors enable you to expand the size of the monitor or duplicate the desktop so you can view additional windows. For example, the woman in Figure 3-41 is using multiple displays. She is using the monitor on the right to make changes to a website and the monitor on the left to display the resulting changes. She is also using a laptop to display a library of images she is considering for inclusion in the website.

Many computers have built-in support for multiple monitors. To connect multiple monitors to a computer, you need the supporting cables. You also need to enable your computer to support multiple monitors.

For example, on a Windows 10 host, right-click anywhere on the Desktop and choose Display settings. Windows should open the Display window, as shown in Figure 3-42. In the example, the user has two monitors connected in the configuration displayed. The current monitor selected is highlighted in blue and has a resolution of 1920×1080. It is also the main display monitor. By clicking on monitor 1 or 2 you could see the resolution of that monitor.

Motherboard Upgrade (3.4.1.1)

Computers need periodic upgrades for various reasons:

• User requirements change.

• Upgraded software packages require new hardware.

• New hardware offers enhanced performance.

Changes to a computer may lead you to upgrade or replace components and peripherals. Research the effectiveness and cost of both upgrading and replacing.

If you upgrade or replace a motherboard, consider that you might have to replace other components, including the CPU, the heat sink and fan assembly, and RAM. A new motherboard must also fit into the old computer case, and the power supply must support it.

When upgrading the motherboard, if the CPU and the heat sink and fan assembly are to be reused, move them to the new motherboard. These items are much easier to work with when they are outside the case. Work on an antistatic mat and wear antistatic gloves or an antistatic wrist strap to avoid damaging the CPU. If the new motherboard requires a different CPU and RAM, install them at this time. Clean the thermal compound from the CPU and heat sink. Remember to reapply thermal compound between the CPU and the heat sink.

Steps to Upgrade a Motherboard (3.4.1.2)

Before beginning an upgrade, ensure that you know where and how everything is connected. Always make notes in a journal to record how the computer is originally set up. A quick way is to use a cell phone to take pictures of important items, such as how components connect to the motherboard. These pictures may be very helpful during reassembly.

To upgrade a motherboard from a computer case, follow these steps:

Step 1. Record how the power supply, case fans, case LEDs, and case buttons attach to the old motherboard.

Step 2. Disconnect the cables from the old motherboard.

Step 3. Disconnect the expansion cards from the case. Remove each expansion card and place all the cards in antistatic bags or on an antistatic mat.

Step 4. Carefully record how the old motherboard is secured to the case. Some mounting screws provide support, and some provide an important grounding connection between the motherboard and chassis. In particular, pay attention to screws and standoffs that are non-metallic because they may be insulators. Replacing insulating screws and supports with metal hardware that conducts electricity might damage electrical components.

Step 5. Remove the old motherboard from the case.

Step 6. Examine the new motherboard and identify where all the connectors are, such as power, SATA, fan, USB, audio, front panel connector, and any others.

Step 7. Examine the I/O shield located at the back of the computer case. Replace the old I/O shield with the I/O shield that comes with the new motherboard.

Step 8. Insert and secure the motherboard into the case. Be sure to consult the case and motherboard manufacturer’s user guides. Use the proper types of screws. Do not swap threaded screws with self-tapping metal screws, which would damage the threaded screw holes and might not be secure. Make sure the threaded screws are the correct length and have the same number of threads per inch. If the thread of screws is correct, they fit easily. If you force a screw to fit, you can damage the threaded hole, and it will not hold the motherboard securely. Using the wrong screw can also produce metal shavings that can cause short circuits.

Step 9. Connect the power supply, case fans, case LEDs, front panel, and any other required cables. If the ATX power connectors are not the same size (some have more pins than others), you might need to use an adapter. Refer to the motherboard documentation for the layout of these connections.

Step 10. After the new motherboard is in place and the cables are connected, install and secure the expansion cards.

It is now time to check your work. Make sure that there are no loose parts or unconnected cables. Connect the keyboard, mouse, monitor, and power. If a problem is detected, shut off the power supply immediately.

CPU Upgrade (3.4.1.3)

One way to increase the power of a computer is to increase the processing speed. You can do this by upgrading the CPU (see Figure 3-43). The CPU must meet the following requirements:

• The new CPU must fit into the existing CPU socket.

• The new CPU must be compatible with the motherboard chipset.

• The new CPU must operate with the existing motherboard and power supply.

The new CPU might require a different heat sink and fan assembly. The assembly must physically fit the CPU and must be compatible with the CPU socket. It must also be adequate to remove the heat of the faster CPU.

View thermal settings in the BIOS to determine if there are any problems with the CPU and the heat sink and fan assembly. Third-party software applications can also report CPU temperature information in an easy-to-read format. Refer to the motherboard or CPU user documentation to determine if the chip is operating in the correct temperature range.

To install additional fans in the case to help cool the computer, follow these steps:

Step 1. Align each fan so that it faces the correct direction to either draw air in or blow air out.

Step 2. Mount each fan using the predrilled holes in the case. It is common to mount fans near the top of the case to blow hot air out and near the bottom of the case to bring air in. Avoid mounting two fans close together if they are moving air in opposite directions.

Step 3. Connect the fan to the power supply or the motherboard, depending on the case fan plug type.

Storage Device Upgrade (3.4.1.4)

Instead of purchasing a new computer to get faster speed and more storage space, you might consider adding another hard drive (see Figure 3-44).

There are several reasons for installing an additional drive, including the following:

• To increase storage space

• To increase hard drive speed

• To install a second operating system

• To store the system swap file

• To provide fault tolerance

• To back up the original hard drive

After selecting the appropriate hard drive for the computer, follow these general guidelines for installation:

Step 1. Place the hard drive in an empty drive bay and tighten the screws to secure the hard drive.

Step 2. Connect the drive to the motherboard, using the correct cable.

Step 3. Attach the power cable to the drive.

Peripheral Upgrades (3.4.1.5)

Peripheral devices periodically need to be upgraded. For example, if a device stops operating or if you wish to improve performance and productivity, an upgrade might be necessary.

These are a few reasons for upgrading a keyboard and/or a mouse:

• You might want use a keyboard and mouse with an ergonomic design, such as those shown in Figure 3-45. Ergonomic devices are made to be more comfortable to use and to help prevent repetitive motion injuries.

  

• You might want to reconfigure the keyboard to accommodate a special task, such as typing in a second language with additional characters.

• You might need to accommodate users with disabilities.

Sometimes, however, it is not possible to perform an upgrade using the existing expansion slots or sockets. In this case, you might be able to accomplish the upgrade by using a USB connection. If the computer does not have an extra USB connection, you must install a USB adapter card or purchase a USB hub, such as the one shown in Figure 3-46.

Power Supply Upgrade (3.4.1.6)

Upgrading your computer hardware will most likely also change its power needs. If so, you might need to upgrade your power supply. You can find calculators on the Internet to help you determine whether you need to upgrade the power supply. Search for “power supply wattage calculator.”

What Do You Already Know? - Configure a CAx Workstation (3.4.2.1)

One type of specialized computer is a workstation used to run computer-aided design (CAD) or computer-aided manufacturing (CAM) software.

A CAD or CAM (CAx) workstation is used to design products and control the manufacturing process. CAx workstations are used to create blueprints and to design homes, cars, airplanes, computers, and many of the parts in the products that you use every day. A computer used to run CAx software must support the needs of the software and the I/O devices that the user needs to design and manufacture products. CAx software is often complex and requires robust hardware.

What do you already know about configuring CAx workstations?

What Do You Already Know? - Configure an Audio Video Editing Workstation (3.4.2.2)

An audio editing workstation is used to record music, create music CDs, and create CD labels. A high-end video editing workstation can be used to create television commercials, prime-time programming, movies for the theater, or home movies.

Specialized hardware and software are combined to build a computer to perform audio and video editing. Audio software on an audio editing workstation is used to record audio, manipulate how the audio sounds through mixing and special effects, and finalize recordings for publication. Video software is used to cut, copy, combine, and change video clips. Special effects are also added to video using video software.

What do you already know about configuring audio and video editing workstations?

What Do You Already Know? - Configure a Virtualization Workstation (3.4.2.3)

You might need to build a computer for a customer who uses virtualization technologies. Simultaneously running two or more operating systems on one computer is called virtualization. Often, an operating system is installed, and virtualization software is used to install and manage additional installations of other operating systems. Different operating systems from multiple software companies may be used.

Another type of virtualization, called Virtual Desktop Infrastructure (VDI), allows users to log in to a server to access virtual computers. Input from the mouse and keyboard is sent to the server to manipulate the virtual computer. Output such as sound and video is sent back to the speakers and the display of the client accessing the virtual computer.

Low-powered thin clients use a server that is much more powerful to perform difficult calculations. Laptops, smartphones, and tablets can also access VDI to use virtual computers. These are some other uses of virtual computing:

• Testing software or software upgrades in an environment that does not hurt the current operating system environment

• Using more than one type of operating system on one computer, such as Linux or macOS

• Browsing the Internet without harmful software hurting the main installation

• Running old applications that are not compatible with modern operating systems

Virtual computing requires more powerful hardware configurations because each installation needs its own resources. One or two virtual environments can be run on a modern computer with modest hardware, but a complete VDI installation may require fast, expensive hardware to support multiple users in many different environments.

What do you already know about configuring a virtualization workstation?

What Do You Already Know? - Configure a Gaming PC (3.4.2.4)

Many people enjoy playing computer games. Each year, games become more advanced and require more powerful hardware, new hardware types, and additional resources to ensure a smooth and enjoyable gaming experience.

What do you already know about configuring a gaming PC?

Thick and Thin Clients (3.4.2.6)

Computers are sometimes referred to as thick and thin clients:

• Thick clients: Sometimes called fat clients, these are the standard computers that we have discussed in this chapter. The computers have their own operating system, a multitude of applications, and local storage. They are standalone systems and do not require a network connection to operate. All the processing is performed locally on the computer.

• Thin clients: These are typically low-end network computers that rely on remote servers to perform all data processing. Thin clients require a network connection to a server and usually access resources using a web browser. However, the client can be a computer running thin client software or a small, dedicated terminal consisting of a monitor, keyboard, and mouse. Typically the clients do not have any internal storage and have very few local resources.

Table 3-7 identifies differences between thick and thin clients.

Along with thick and thin clients, there are computers that are built for specific purposes. A computer technician is responsible for evaluating, selecting appropriate components, and upgrading or custom-building specialized computers to meet the needs of customers.

This section identifies and discusses some of these specialized computers.

NAS (3.4.2.7)

Network-attached storage (NAS) devices, such as the one shown in Figure 3-47, are servers that are connected to a network to provide file-level data storage to clients. This specialized computer is sometimes single-purposed, running a stripped-down operating system to perform only the function of file serving. Sometimes the device can offer additional functionality, such as media streaming, network services, automated backup functions, website hosting, and many other services.

A NAS may offer high-speed networking through the use of a gigabit network interface card (NIC). This interface allows many simultaneous connections to the network at very high speed. Some NAS devices have more than one gigabit NIC to allow many more connections.

Recommended practice dictates using a special hard drive when deploying a NAS device. These drives are specially built to endure the always-on environment of a NAS system. It is very common to find multiple drives within a NAS not only to provide additional storage but also to provide either increased speed or redundancy through the use of RAID.

Safe Disposal Methods (3.5.1.1)

After upgrading a computer or replacing a broken device, what do you do with the leftover parts? If the parts are still good, they can be donated or sold. Parts that no longer work must be disposed of, but they must be disposed of responsibly.

The proper disposal or recycling of hazardous computer components is a global issue. Make sure to follow regulations that govern how to dispose of specific items. Organizations that violate these regulations can be fined or may face expensive legal battles. Regulations for the disposal of the items listed in the following sections vary from state to state and from country to country. Check with your local environmental regulatory agency.

Safety Data Sheets (3.5.1.2)

Hazardous materials are sometimes called toxic waste. These materials can contain high concentrations of heavy metals such as cadmium, lead, or mercury. The regulations for the disposal of hazardous materials vary by state or country. Contact the local recycling or waste removal authorities in your community for information about disposal procedures and services.

A safety data sheet (SDS), formerly known as a material safety and data sheet (MSDS), is a fact sheet that summarizes information about material identification, including hazardous ingredients that can affect personal health, fire hazards, and first-aid requirements. An SDS contains chemical reactivity and incompatibility information. It also includes protective measures for the safe handling and storage of materials and spill, leak, and disposal procedures. To determine whether a material is classified as hazardous, consult the manufacturer’s SDS, which in the U.S. is required by OSHA when the material is transferred to a new owner.

The SDS explains how to dispose of potentially hazardous materials in the safest manner. Always check local regulations concerning acceptable disposal methods before disposing of any electronic equipment.

In the European Union, the regulation Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) came into effect June 1, 2007, replacing various directives and regulations with a single system.