220-1201 Hardware Study Guide for the CompTIA A+ Core Series Exam

Power Supply

Power supplies convert AC power to DC power, which is what computer components run on. There are different types of power supplies to fit different types of computers. Each power supply has specific features related to capacity and connectors. You must be able to select the proper power supply type and features needed in any given scenario.

Input 110–120 V AC vs. 220–240 V AC

The input to a power supply is provided by the power company. This is the power available at a wall outlet. In North America and some other parts of the world, 110 to 120 volts AC (alternating current) is supplied. Other countries supply 220 to 240 volts AC. So, most power supplies are designed to accept either of these inputs. Some have a switch to set for the correct input. Others accept either input without having to set a switch.

Output 3.3 V vs. 5 V vs. 12 V

Power supply voltage is measured as either positive or negative, which indicates if the potential power difference is either higher (positive) or lower (negative) than the reference point, usually the ground. In computing infrastructures, negative voltages are commonly used to replicate signals from devices with both positive and negative components, such as switches and amplifiers.

Most power supplies provide +5 V and +12 V. Others may also provide -12 V, -5 V, and +3.3 V. You may see more than one connector for a specific output. For example, you may see two +12 V outputs, each with its own connector. Each output is called a rail, so in this example, there would be two +12 V rails. When choosing a power supply, always identify the appropriate supply prior to installation.

20+4 Pin Motherboard Connector

Most power supplies provide DC output power on a standard 24-pin connector, also called the ATX power connector, which plugs into the motherboard. The connector is keyed so that it can only plug in one way, ensuring that the proper voltages are supplied to the right pins. Specific pins are designated to supply +5 V, +12 V, -12 V, and +3.3 V.

Redundant Power Supply

A redundant power supply is a secondary power supply that provides power to a device in case of power failure. Redundant power supplies are commonly internal power supplies installed within a specific device or rack mounted power supplies that are installed in the rack housing the devices the power supply supports.

Modular Power Supply

A modular power supply is a power supply that is not permanently attached to the device. This provides the potential for additional power connections to the device. A modular power supply, unlike a redundant power supply, allows for the quick connection and removal of devices to the power supply. Modular power supplies are not installed within the device, nor are they rack mounted, facilitating ease of access, installation, and removal.

Wattage Rating

Wattage rating, or power rating, is the total capacity of the power supply. This must be high enough to meet the total power demands of all components in the computer. The number and types of devices or components in any given computer determine what wattage rating is needed for the power supply. They also determine what types of connectors are needed to ensure that you can connect the power supply to each device. The type of case the computer is within also needs to be considered to ensure that the power supply physically fits properly.

To determine the wattage requirement of the power supply, add all of the wattage ratings of the individual components. Your power supply’s wattage must at least meet (but preferably exceed) that total value. The connectors needed are determined by the connector types used on the devices to be powered. For example, if you have an older ATX motherboard, it will have a 20-pin power connection, while newer models contain the 24-pin Molex power connection.

Energy Efficiency

PC power supplies are assigned an energy efficiency rating that is used to measure how well the power supply converts AC wall power to the DC power used by the computer. Most power supplies use the 80 PLUS standard, which has the following certifiable designations: Standard, Bronze, Silver, Gold, Platinum, Titanium, and Ruby. There are currently seven different categories of certifiable power supplies, each with different efficiency level requirements. To be certified, however, all power supplies must have at minimum 80% efficiency at rated load.

Multifunction Devices

You must be able to identify, deploy, and configure multifunction devices and printers with the appropriate settings. The questions about these concepts will be scenario-based.

Unboxing and Location

When installing a multifunction device or printer, read the manufacturer’s instructions first. The next step is to evaluate the needs of the user, the demands that will be placed on the device, and the most appropriate location for maximized efficiency. When unboxing the device, be sure the box is set on a stable flat surface. Avoid banging or dropping the device. Lift the device out in the proper orientation to avoid tipping the device, which is particularly important with printers that use toner cartridges.

Appropriate Drivers

Most devices will come with easy installation media. Windows devices will automatically recognize a device upon connection and powerup. Install the appropriate driver for the OS and the device. Install any updates for the appropriate drivers.

PostScript vs. Printer Control Language (PCL)

PostScript and PCL are two printer communication languages. PostScript is an older technology and is device-independent, which allows for print jobs to result in the same output regardless of the printer used. PCL is a newer and more common printing language that is device-dependent. This means that the printer itself is responsible for some of the printing data, which may result in slightly different outputs depending on the printer used.

Firmware

The firmware of a multifunction device is the software embedded within the device that provides functionality. Multifunction devices, such as printers, have low-level firmware, such as the BIOS/UEFI, which is used for initialization and basic functions, and high-level firmware, which is used for more specific functionality such as printing and scanning.

Device Connectivity

A printer’s interface is the hardware and software that a printer uses to connect with devices or a network. The hardware interface used by a printer is commonly called the port. A printer can only be used with the correct interface.

Universal Serial Bus (USB)

The USB connection is the most common wired connection method for printers. A USB port will allow for the connection of a physical USB cable to the appropriate device.

Ethernet

Printers that are designed to work on a network will have an RJ45 Ethernet connector. They connect to the network with an Ethernet cable, just as a computer would. They are easily shared since they are connected directly to the network.

Wireless

Wireless connections to printers may be made via Bluetooth, 802.11, or a direct ad hoc connection.

Public/Shared Devices

Devices can be shared by multiple users over wired or wireless connections. Users can connect directly to a printer or through a print server or cloud printing service. SOHO devices can be made available and shared with anyone on a network. This is true for devices that are connected directly to the network or connected to a computer. If a printer is connected to a computer, then the operating system must be configured to make the printer available to users on the network.

Printer sharing is the process of providing access to a printer to other computers and devices on a network.

Print Server

A print server sits on the network and handles printing requests from users. It can spool (temporarily store) requests for printers that are busy, allow prioritization of print jobs, and delete jobs after they’ve been sent. Print servers may be separate devices or integrated into the printer.

Configuration Settings

Configuration settings are the settings within a printer that can be optimized to best suit the needs of the users. Configuration settings can be accessible to all users or restricted to authorized users only.

Duplex

Enabling duplex mode allows the printer to print on both sides of the paper.

Orientation

There are two options for orientation: portrait or landscape. In portrait mode, the top of the page is the shorter dimension. This is how pages are typically printed. In landscape mode, the top of the page is the longer dimension. Spreadsheets and slides are often printed in landscape mode.

Tray Settings

The tray settings control how the printer manages the individual paper trays in the device.

Quality

Print quality settings control resolution and color. Resolution is expressed in dots per inch (dpi), with higher resolutions providing better quality printouts. Color settings control how vivid the color output is.

Security

Giving access to users over the network raises concerns over data privacy. Steps must be taken to ensure that users cannot read other users’ print jobs.

User Authentication

Users can be required to authenticate to print servers. They typically authenticate at one of two security levels: user or administrator. Users are limited to printing and managing their own print jobs. This prevents other users from seeing or interfering with other users’ print jobs. Administrators can manage all print jobs.

Badging

Badging is the process of requiring a user to swipe or tap a physical access control card with an associated electronic reader prior to access. The badge reader communicates with the electronic component in the card to verify identity. Badging is a function that can be used for the security of a printer by only allowing access after badging.

Audit Logs

Audit logs keep a record of all print jobs along with the originating location of the print jobs for later auditing.

Secured Prints

Secured prints are printouts that require authentication at the physical printer before a print job commences. This ensures that the intended recipient of the print is present to reduce the likelihood of another unauthorized user grabbing or seeing a sensitive print.

Network Scan Services

Network scan services are hardware and software functions designed to input or scan documents. Scans taken on a printer or scanning device can be set to record the scanned information in a specified manner.

Email

Scan to email occurs when a printer/scanner is instructed to send the scanned image or document to a specific email address or group of addresses, typically in a PDF file.

Secure Message Block (SMB)

Scan to folder is the process of sending a scanned document or image to a specified folder. The protocol used by the printer/scanner to send data to a network folder is SMB.

Cloud Services

Scan to cloud occurs when a printer/scanner is instructed to send a scanned image or document to a specified cloud location or service. It is supported by popular cloud services, such as Google Drive, OneDrive, and Dropbox.

Automatic Document Feeder (ADF)/Flatbed Scanner

There are two primary types of scanners. An ADF is a scanning device that allows for multiple pages to be scanned automatically through the use of a feeder, eliminating the need to manually change the document being scanned. A flatbed scanner is a scanning device that requires manual placement of a document to be scanned onto a flat scanning surface with a closable lid.