Week Ten

Components of a Laser Printer

• Toner Cartridge - Supplies the toner that creates the image on the page. 
• Photosensitive Drum - An aluminum cylinder coated with particles of photosensitive compounds.
• Erase Lamp - Exposes the entire service of the photosensitive drum to light, making the photosensitive coating conductive.
• Primary Corona/Charge Roller - Charged with an extremely high voltage, causing an electric field enabling voltage to pass to the drum and charge the photosensitive particles on the service. 
• Laser - The writing mechanism of the printer. Any particle on the drum struck by the laser becomes conductive and its charge is drained away in o the grounded core of the drum.
• Toner - A fine powder made up of plastic particles bonded to iron particles. Particles of toner are attracted to the areas of the photosensitive drum that have been hit b the laser.
• Transfer Corona/Transfer Roller - To transfer the image from the photosensitive drum to the paper, the paper must be given a charge that will attract the toner particles off of the drum and on to the paper. Newer printers use a transfer roller that draws the toner onto the paper.
• Fuser Assembly - Two rollers, a pressure roller and a heated roller, are used to fuse the toner to the paper. The pressure roller presses against the bottom of a page, while the heated roller presses on the top to melt the toner into the paper.
• Power Supplies - All laser printers have at least two power supplies. One provides power to the motors that move the paper, the laser, and the transfer corona/roller. The high voltage supply provides power only to the primary corona/roller.
• Turning Gears - Used to pick up the paper, turn the photosensitive roller, evenly distribute the toner, and activate the fuser assembly. In most laser printers gear systems are packed together in units called gear packs. Most laser printers have two or three gear packs. 
• System Board - On each electronic board is a processor, the printer's ROM, and the RAM used to store the image before it is printed. Many printers divide these components among two or three boards.
• Ozone Filter - Special filter to catch ozone. Needs to be vacuumed or replaced periodically.
• Sensors and Switches - Spread throughout the printer. The sensors detect issues such as paper jams or low toner levels.

Source:

Meyers, M. (2012). All-in-one CompTIA A certification exam guide: (exams 220-801 & 220-802). New York: McGraw-Hill.

Week Nine

Troubleshooting Sound

Having sound problems in Windows can be a frustrating experience. Either it is simple to fix, or seemingly impossible. Sound problems tend to fall within three groups: hardware, configuration, and application problems.

1. Hardware - Many sound problems are caused by hardware that isn't set up properly.

• The first thing to check when sound dies is the volume controls. Volume can typically be set in two areas: in software, and on the speakers.
• The second thing to check is the speakers. Make sure they are turned on and are getting power. Also check if they are plugged in to the sound card.

2. Configuration Problems - Configuration errors can occur when the sound card is physically good but a setting has not been properly configured. These errors typically occur at installation but can also appear on a working system.

• First place to check is the device manager. If the driver has a problem it will be displayed. 
• Second place to check is the Sound applet for configuration errors. 

3. Application Problems - Application problems are the hardest to fix and tend to occur when it was previously playing sounds without trouble.

• First, look for an error message. If an error code occurs, this can be researched online.
• Second - Try playing the sound file with a different application.
• Third - Try reinstalling the application.

Source:
Meyers, M. (2012). All-in-one CompTIA A certification exam guide: (exams 220-801 & 220-802). New York: McGraw-Hill.

Week Eight

Configuring Internet Explorer

On most web browsers you can set the default font size, choose whether to display graphics, and adjust many other settings. Using Internet Explorer (IE) you will find configuration tools under Internet Options in the Control Panel or under the Tools menu on Internet Explorer. When the Internet Options applet is launched there are seven tabs along the top: General, Security, Privacy, Content, Connections, Programs, and Advanced.

The General tab controls the most basic features of Internet Explorer: the home page, browsing history, and tab settings. The Security tab enables you to set how severely IE safeguards your Web browsing. Each setting can be adjusted for a particular zone: Internet, Local intranet, Trusted sites, and Restricted zones. Once you have picked a zone to control, you can set IE's security level.

The Privacy tab controls privacy matters such as cookies and pop-ups. You can choose to block everything on the highest setting, or block nothing on the lowest setting.

The Content tab controls what your browser will and will not display. It uses a Content Advisor which uses ratings that consider language, gambling, and more. You can also adjust the AutoComplete feature which fills in web addresses under this tab.

The Connections tab allows you to set up your connection to the internet, connect to a VPN, configure a proxy server, or adjust LAN settings.

The Programs tab contains settings for your default web browser, any add-ons you may use, and how other programs deal with HTML files and email messages.

The Advanced tab contains a lot of different options that you can check or uncheck with a box, including: accessibility, browsing, international, and security settings.

Source:
Meyers, M. (2012). All-in-one CompTIA A certification exam guide: (exams 220-801 & 220-802). New York: McGraw-Hill.

Week Seven

Biometric Devices

Biometric devices scan and remember unique aspects of various body parts. This can include your iris, head image, or fingerprint. This information is used as a key to prevent unauthorized users from accessing whatever the biometric device is securing. There are many different types of biometric devices, such as:

• Fingerprint USB thumb drive: has a tiny fingerprint scanner. You slide your finger over the drive to unlock the contents of the thumb drive.
• Microsoft fingerprint scanner: replaces the standard username and password authentication. When a web site asks for a username and password you simply press your finger against the fingerprint scanner. It will then confirm your identity with special software.
• Fingerprint scanners: Used to gain access to a specific area, such as a data center. Can be troublesome if a user's fingerprint is damaged or altered.
• Iris and retinal scans: considered to be more secure form of biometric authentication.

Implementation of biometric systems can be tricky and sometimes expensive. Because of this, biometrics should only be considered for extremely sensitive data.

Sources:

Biometric authentication know-how: Devices, systems and implementation. (n.d.). Retrieved April 28, 2016, from http://searchsecurity.techtarget.com/tip/Biometric-authentication-know-how-Devices-systems-and-implementation

Meyers, M. (2012). All-in-one CompTIA A certification exam guide: (exams 220-801 & 220-802). New York: McGraw-Hill.

Week Six

Command-Line Interface

The command-line interface (CLI) is like having an Instant Message conversation with your computer. The computer displays a prompt when it is ready to receive a message. Once a command is entered the computer executes the command, and when it is finished displays a new prompt and information about what it did. To access the CLI you can go to Start, Run and type cmd or command, or on newer versions of Windows type cmd or command in the search box on the Start menu. It can also be found in the Start menu under Programs, Accessories.

Common CLI Commands
dir - Shows you the contents of the directory where the prompt is focused.
cd (or chdir) - change the focus of the command prompt to a different directory.
md (or mkdir) - create a directory.
rd (rmdir) - removing a subdirecory.
ren (or rename) - rename a file.
del (or erase) - delete a file.

Sources:
Meyers, M. (2012). All-in-one CompTIA A certification exam guide: (exams 220-801 & 220-802). New York: McGraw-Hill.

Week Five

Windows Registry

The Windows Registry contains information, settings, options, and other values for programs and hardware installed on the Microsoft Windows operating system. Every version of Windows stores the Registry files, known as hives, in the System32\config folder and each user account folder. When a new program is installed a new subkey is created in the Registry. This includes the program's location, it's version, and how to start the program.

Accessing the Registry
The Registry can be accessed directly using a Registry editor. To access the Registry editor you can enter either regedit or regedt32 at a command prompt, or by using the Start, Run dialog box. Either command will bring up the same program.

Before Editing the Registry
The Windows Registry should rarely be edited, unless there is no other option. By making changes in the registry you risk breaking things in Windows. For example:

• Programs may not start
• Utilities may not work
• The computer may not boot

To prevent these problems a backup of the Registry may need to be taken before anything is modified. 

Sources:

Fisher, T. (2015, November 05). What is the Windows Registry? Retrieved April 14, 2016, from http://pcsupport.about.com/od/termsr/p/registrywindows.htm

Meyers, M. (2012). All-in-one CompTIA A certification exam guide: (exams 220-801 & 220-802). New York: McGraw-Hill.

Week Four

Device Drivers

A device driver, also known as a hardware driver, is a group of files that enable one or more hardware devices to communicate with the operating system. Device drivers are used for devices such as a printer or an external hard drive. Device drivers communicate with software. A software program explains what it wants a piece of hardware to do and the device driver takes the information and fulfills the request with the hardware. Device drivers are usually installed automatically. Sometimes it is necessary to troubleshoot device drivers, which can be done through the Device Manager on Windows. The Device Manager allows you to view installed hardware, and is sorted by category. Sometimes the Device Manager will show which devices are not working properly by displaying a yellow triangle with an exclamation point over a device's icon. From the device manager you are also able to perform maintenance by updating, disabling, rolling back, or uninstalling a driver.

Sources:

Fisher, T. (2016, March 16). What is a Device Driver? Retrieved April 07, 2016, from http://pcsupport.about.com/od/termsag/g/term_driver.htm

Hoffman, C. (2013, July 07). How to Use the Windows Device Manager for Troubleshooting. Retrieved April 07, 2016, from http://www.howtogeek.com/167094/how-to-use-the-windows-device-manager-for-troubleshooting/

What is device driver? (n.d.). Retrieved April 07, 2016, from http://www.computerhope.com/jargon/d/driver.htm