The A+ Exams Guide: (Exam 220-301), (Exam 220-302) (TestTakers Guides)

An important acronym to be familiar with is Electrostatic Discharge (ESD). ESD is a phenomenon that occurs when electricity builds up (usually in a person's body) and is passed on to the computer and its components. ESD can cause serious damage to your computer and components. You should always wear a protective ESD wrist strap, which contains a resistor, when handling the components inside the system unit. Expansion cards, such as a Network Interface Card (NIC) or video adapter card, have onboard memory and Read-Only Memory (ROM) chips that can be damaged by ESD. Always wear a protective wrist strap when installing these components. Never use a piece of wire to ground yourself if you are using an ESD wrist strap. Instead, use a grounded ESD mat to absorb and discharge electricity. In addition, you should never wear an ESD wrist strap when working on a monitor. A monitor can store high levels of voltage (about 15,000V), which can cause serious bodily harm when interacting with a resistor in an ESD strap. Warm and dry environments are a breeding ground for static electricity buildup. Place any spare electronic components, such as motherboards, hard drives, memory modules, and processors, in reusable ESD protective bags and store them in a cool and dry environment. When cleaning the inside of your computer, be sure to use a special-purpose vacuum that is designed to not create ESD.

Use the following guidelines for keeping your system clean:

• ROM media. Dip media in a diluted cleaning solution and let air dry.

• Inside of computer. Spray with a can of condensed air. Use a small brush for the system unit itself.

• Airflow. Use two internal fans to keep the air cool and circulating inside your system. This prevents too much dust from settling between components.

• Circuit boards. Clean with a contact cleaning solution.

• Electromagnetic Interference (EMI) is caused when electrical wires are placed too close to each other, or when the wires cross each other. This can cause havoc with computer signals traveling down a wire.

Another consideration in an electronic environment is fire safety. You should have a plan in case of fire, and have the proper equipment available and ready to use in case of fire. To extinguish an electrical fire, use a Type C or multipurpose-Type ABC extinguisher. In an environment with a built-in preventive sprinkler system, consider having protective plastic drop cloths available to cover your most important computer systems. If a fire detection sprinkler system is in place, and fire is detected, you could lose electronic assets to water damage.

There are four types of handheld fire extinguishers you should be familiar with. They are:

• Air Pressurized Water (APW). An APW fire extinguisher is a large, silver, handheld extinguisher that is filled with a combination of air and water. It should never be used to put out a chemical or electrical fire. This is an older type of extinguisher that is used primarily to take the heat element away from a fire.

• Dry Chemical (ABC and BC). These types of handheld extinguishers are very effective at putting out various types of fire. Dry chemical extinguishers smother a fire with a phosphorous chemical that separates the oxygen and fuel within a fire. ABC-type extinguishers can be used to put out chemical, electrical, or wood/paper burning fires. You can identify whether the extinguisher is an ABC or a BC extinguisher by the pictures and labels on the extinguisher itself. Caution: never use a BC extinguisher on a Class A fire. Class BC fires are electrical and chemical, only. Class A fires are paper/wood burning fires. Simply put, educate yourself on the type of extinguishers available at your facility. Chances are that you have ABC-type fire extinguishers in your building.

  Note

  Computer-related electrical fires should be extinguished with an extinguisher that is rated for Class C fires. For the exam question, 'Your company's main server computer is on fire!' use a Class BC or C extinguisher.

• Carbon Dioxide (CO2). This type of extinguisher uses carbon dioxide gas to remove or displace the oxygen in a burning fire. It can easily be identified by a hard black ‘horn' or spout, which is used to spray the chemical. Carbon dioxide handheld fire extinguishers are designed to put out BC-type fires.

• Halon. Halon extinguishers are filled with a gas instead of a chemical powder. This gas is more effective at putting out ABC-type fires than an ABC-type extinguisher. Besides providing better fire suppression than the previously mentioned extinguisher types, a Halon extinguisher will not ruin the electrical devices that you have just saved from fire destruction. The chemicals in an ABC-type extinguisher will ruin electrical wires, computers, or anything else you use them on. Although Halon works well at putting out fires, Halon extinguishers are banned in many places. It has been scientifically proven that Halon gas depletes the ozone layer, and Halon is considered very dangerous to humans. A good substitute for Halon is FM-200. FM-200 is a widely accepted, chemical-based fire suppressor that extinguishes fire by cooling or removing the heat from the flames.

Material Safety Data Sheet (MSDS)

A Material Safety Data Sheet (MSDS) is a document created and posted for workers, emergency personnel, and officials, which specifies a set of guidelines regarding the proper handling, transporting, storage, and disposal of a hazardous substance or chemical. Most MSDSs also contain information regarding first-aid treatment, should exposure to danger occur. They are usually prominently displayed for easy reference in areas where a danger exists. In an emergency, such as exposure to a toxic chemical, the proper actions can be taken to treat the situation based on the information posted on the MSDS. The failure of a company or organization to create and post MSDSs in required (hazardous) areas might result in serious consequences to a business, such as a fine or loss of their business license.