Chapter 17. Safety and Environmental Issues

This chapter covers the CompTIA A+ 220-701 objective 6.1.

When dealing with computers, power, networking, and anything else in IT, remember to put safety on the top of your priority list. Computer equipment is not a toy and should be treated with care. Another issue to consider is how you dispose of your technology, since this will affect the environment. Most companies have procedures in place that specify what to do with computers, monitors, batteries, and other technology equipment after it has outlived its usefulness to the company. This chapter discusses some of the more common practices when it comes to environmental issues, and it identifies what to watch out for when working on computers. Finally, it demonstrates how to keep yourself and the computer protected and safe.

“Do I Know This Already?” Quiz

The “Do I Know This Already?” quiz allows you to assess whether you should read this entire chapter or simply jump to the “Exam Preparation Tasks” section for review. If you are in doubt, read the entire chapter. Table 17-1 outlines the major headings in this chapter and the corresponding “Do I Know This Already?” quiz questions. You can find the answers in Appendix A, “Answers to the ‘Do I Know This Already?’ Quizzes and Troubleshooting Scenarios.”

Table 17-1 “Do I Know This Already?” Foundation Topics Section-to-Question Mapping

1. One of your clients is in need of a replacement laptop battery. What should you do with the failed battery?

a. Throw it in the trash can

b. Make sure it has been discharged completely and then throw it away

c. Keep it just in case it is still good

d. Send the battery to a recycling center

2. The company you work for has purchased all new computers. Your boss wants you to get rid of all the older equipment. Which of the following are the best alternatives to throwing away the older equipment? (Choose all that apply.)

a. Donate it to a charity

b. Give it to an electronics trade school

c. Bring it to a recycling center

d. Bring it to a municipal incinerator

3. Which of the following are uses for the material safety data sheet (MSDS)? Choose all that apply.

a. Determine safe storage practice

b. Determine treatment if a product is accidentally swallowed or contacts the skin

c. Determine safe disposal methods

d. Determine how to deal with spills, fire, and other hazards

e. Determine safe storage and safe disposal methods only

4. You are working in the shop with a co-worker. You notice that he has just spilled a substance on the floor. What should you tell your co-worker to do at this point?

a. Mop up the chemical

b. Use a wet vac to vacuum up the material

c. Check the MSDS for instructions

d. Leave it on the floor until it evaporates

5. You are working on a client’s computer. You are about to install a new video card in the computer. When you reach to open the case you get a small shock. What is this known as?

a. MSU

b. GUI

c. ESD

d. ESDT

6. You have just completed a computer upgrade on a client’s computer. What should you do with the components that you have taken out of the system?

a. Place them in the antistatic bags that came with the new hardware

b. Put them in the boxes that the new hardware came in

c. Throw them in the trash because you don’t need them anymore

d. Sell them to a computer store

7. Which of the following is the most effective way to prevent ESD from happening to you when working on a computer?

a. Make sure you are free of static before starting to work

b. Wear rubber-soled shoes

c. Be sure to work with both hands inside the computer

d. Use an antistatic work mat equipped with a wrist strap

8. Which of the following can be considered hazards in you computer area? (Choose all that apply.)

a. High voltage sources

b. Printers

c. Cable locations

d. Atmospheric hazards

e. All of these options are correct

9. You are the lead technician for your company. You walk in the office one morning and notice a co-worker is servicing a computer with the power cable still plugged in. What should you tell your co-worker to do?

a. Tell her to be careful

b. Tell her to use an antistatic wrist band

c. Tell her that she shouldn’t have the power plugged in while working on the computer.

d. Tell her nothing, because it is her choice to do this

10. You are walking into the work area and notice that a technician is lifting a heavy server by himself. What should you say to your co-worker? Choose all that apply.

a. Tell him to wear a back brace

b. Let him do it alone

c. Use the team lift method

d. Watch him to make sure he doesn’t drop the server

11. You are working for a company as a support technician. You walk into a work area and see a co-worker lying on the floor. She is not responsive. What should you do first as quickly as possible?

a. Bring her to the hospital

b. Call 911

c. Contact the manager

d. Ask other co-workers if the person takes special medications

12. You are the lead technician for your company. You have hired a new technician to help you. Which of the following should the new person be aware of in case of injuries, chemical spills, or fires? (Choose all that apply.)

a. Know who to contact in case of emergency

b. Show him the break room

c. Have him review and follow procedures

d. Let him know where the MSDS information is

Foundation Topics

Recycling and Disposal Issues

Nothing lasts forever in the computer business. Whether it is a worn out real-time clock battery, an obsolete monitor, or an empty toner cartridge, there’s a right way to get rid of it or to recycle it. Generally, the more “durable” a computer-related item is, the more likely it is that it should be recycled when it reaches the end of its useful life, instead of simply being discarded.

Disposing of Batteries

Batteries no longer contain significant amounts of mercury, a highly toxic chemical that can cause memory loss, vision impairment, and other health issues in high exposures, but today’s batteries still contain chemicals that should not go into landfills.

Depending on the type of battery that you have replaced, you might find more than one option for disposal of the old ones:

• Some stores have drop-off bins for watch and calculator batteries; the popular 3.0V lithium CR-2032 or equivalent battery used on motherboards to maintain the CMOS and RTC settings could be disposed of this way.

• Hardware stores and home centers often feature drop-off bins for Ni-Cd, NiMH, or Li-ion rechargeable batteries, such as those found in computer, PDA, or cell phone power supplies or power tools.

• To recycle alkaline or other types of dry or wet-cell batteries, including batteries used in UPS battery backup systems, as well as rechargeable, watch, and calculator batteries, contact companies that specialize in safe battery disposal or recycling. To locate companies, check your local telephone directory or perform a web search using search terms such as “battery recycling.”

Recycling Toner and Printer Cartridges

As you learned in Chapter 11, “Printers,” many manufacturers of laser toner and inkjet printer cartridges want you to recycle the empty cartridges; these companies provide postage-paid envelopes or mailing labels to help you return the empty product.

Otherwise, contact local rebuilders of laser toner or inkjet cartridges. Some of these companies might pay you a small fee per empty toner cartridge for popular printer models or might offer other inducements.

Disposing of Chemical Solvents and Cans

When you’ve used the contents of a cleaning product container, check the label for container-disposal instructions. Depending on the product, you might

• Be able to recycle the plastic container in household recycling; this is most often true for citrus-based and other mild cleaners

• Be required to follow toxic material disposal procedures; check with your local EPA office for a “Tox-Away Day” and store your empty containers for safe disposal at that time

If you need additional information about disposing of a particular type of container, check the product’s material safety data sheet (MSDS). See the section “Using an MSDS (Material Safety Data Sheet),” later in this chapter for details.

Disposing of Obsolete Monitors and Computer Hardware

If you send your obsolete PC, printer, or monitor to a landfill, it will have plenty of company. Millions of old units go there every year; it’s legal, but it’s also a waste of equipment that could teach somebody something or still be useful to someone. Here are some better ways to deal with obsolete computers and peripherals:

• If possible, try to dispose of your working, cast-off computer equipment by giving it to a school or charity. These organizations might be able to wring an additional year or two of useful life out of the equipment and are usually grateful for the opportunity.

• To dispose of non-working equipment, see if an electronics trade school is willing to take the equipment for classroom use. Some electronic and computer service facilities will allow you to drop off defective monitors with payment of a small disposal fee.

• Use “computer” and “recycling” in a major search engine such as Google.com to find options for constructive disposal of both working and non-working equipment.

Using an MSDS (Material Safety Data Sheet)

What happens if a toddler decides to taste the ink in a printer cartridge? The Material Safety Data Sheet (MSDS) knows. Many consumable products such as cleaners and printer cartridges have an MSDS. In more and more cases today, this information is available from the manufacturer’s website on the Internet.

The MSDS can be used to

• Determine safe storage practice

• Determine treatment if the product is accidentally swallowed or contacts the skin

• Determine safe disposal methods

• Determine how to deal with spills, fire, and other hazards

The MSDS is divided into sections 1 through 16. For example, to determine first-aid measures in case of ingestion or inhalation, you would view section 4; to view fire-fighting information, go to section 5 (see Figure 17-1).

Figure 17-1 A portion of an MSDS for a typical HP laser printer toner cartridge, viewed with Adobe Acrobat.

For easy reading, many manufacturers use the Adobe Acrobat (.pdf) format; documents in this format can be read by anyone with the free Adobe Reader program, obtainable from www.adobe.com.

Electrostatic Discharge (ESD)

Anyone who works with electronics, especially disassembled components, needs to be very concerned about ESD. ESD is the static electricity discharge that happens when two differently charged objects (such as your body and a computer component) come in contact with each other. ESD is an invisible killer of memory modules, interface cards, hard disks, and other computer components, because ESD buildup and discharge happens long before you actually notice it.

You might dread shaking hands with a new acquaintance in the winter because you’ll get a shock, but ESD discharges far below the 3,000V level that you can actually feel can still destroy chips. As little as 30V of ESD is enough to destroy the current generation of low-powered chips, and you can build up as much as 20,000V of ESD from walking across a carpeted room in the winter if you shuffle along.

ESD damage is “invisible” for another reason: It leaves in its wake equipment that has no visible damage but simply won’t work reliably.

ESD damage is a major cause of intermittent failures, which are the bane of computer technicians everywhere. An intermittent failure is the classic “it wasn’t working when I called you” kind of problem that “goes away” when you examine the system but recurs from time to time later.

Preventing ESD

You can prevent ESD by taking proper precautions when you do the following:

• Install or remove components

• Store and transport components

• Use computers

One way to prevent ESD is to equalize the electric potential of your body and the components on which you’re working.

Unequal electrical potential between you and the device on which you’re working is the major cause of ESD. When your body has a higher electric potential than the device or component with which you’re working, an ESD from your body to the device or component equalizes the potential—but at the cost of damage or destruction to the component.

Power Diagnostics, ESD and Safety

The following items enable you to perform electrical testing on power entering the system (AC) and power levels inside the system (DC), prevent ESD damage to components, and prevent electrical shock caused by worn insulation on power cables. Figure 17-2 shows most of these products.

Figure 17-2 ESD, electrical and safety products used by computer technicians.

• AC/DC multimeter with Ohm and Continuity options— Tests power inside the system and at wall outlets

• Grounded AC circuit tester— Fast testing for wall outlets; many offices and homes are incorrectly wired, and the tester will help you determine whether this is the problem

• Antistatic mat and wrist strap— Prevents ESD, which can damage parts and systems

• Electrical tape— Temporarily repairs worn spots in the insulation of AC and DC power cables until replacements can be obtained

• Battery tester— Helps determine the condition of batteries used in motherboards and other components

Protection Devices

You can best equalize the electrical potential of a computer or component that is being serviced by placing the computer or component on an antistatic work mat equipped with a wrist strap; attach your wrist strap to the mat. This will help place you and the component at the same level of electrical potential, and thus eliminate the “need” for ESD to occur to equalize the potential.

For additional safety, use the alligator clip on the antistatic mat to attach to the component or computer you are working on. Attach the clip to unpainted metal on the chassis, such as the frame. This provides superior equalization for the mat, you, and the hardware on the mat.

Table mats connected to a grounded power supply are useful tools for preventing ESD on working computers, especially if users are reminded to touch the mat or grounded keyboard strip first. Antistatic cleaning spray and antistatic carpet spray should be used in any carpeted office to reduce static, especially in the winter when dry heat causes buildup.

A typical commercial wrist strap and a grounded work mat are shown in Figure 17-3. Both the wrist strap and the work mat include alligator clips that are attached to the system chassis to equalize electrical potential between the wearer and the computer. Wrist straps use hook and loop or other types of adjustable closures; it’s important to wear the wrist strap comfortably snug so that the metal plate underneath the resistor touches the skin to provide proper conductivity.

Figure 17-3 A typical ESD kit includes a grounded work mat and wrist strap. Both have 1-megohm resistors to protect the user from electric shock and alligator clips to connect the mat and wrist strap to unpainted metal parts on or inside the system.

Correct Storage for Equipment

Correct equipment storage should have two goals:

• Eliminating the possibility of ESD

• Protecting equipment from impact damage

To protect equipment from ESD, store equipment in the Faraday cage antistatic bags originally supplied with the equipment; retain bags for installed equipment for reuse. Faraday cage antistatic bags feature a thin metallic layer on the outside of the bag, which is conductive and prevents ESD from penetrating to the components inside. Thus, metalized metallic bags should never be used for temporary mats for components; if you lay a component on the outside of the bag, you’re laying it onto a conductive surface. Colored antistatic bubble wraps also work well for parts storage and can also be used as a temporary mat, too. If you use bubble wrap, make sure it is antistatic (see Figure 17-4).

Figure 17-4 A grounded work mat, suitable for use on either a work area or under an office computer in a high-static area, and antistatic Faraday bags.

All work mats and wrist straps should have a 1-megohm resistor, as shown in Figures 17-3 and 17-4, to stop high voltage that comes through the ground line from injuring the user.

Store components in appropriate boxes to avoid physical damage. If the original boxes have been discarded, use cardboard boxes that have enough room for the component, the Faraday cage bag around the component, and antistatic padding.

Additional ESD Precautions

A grounded wrist strap can help prevent ESD, but you should also follow these additional precautions:

• If you must handle expansion cards and other devices with chips without suitable antistatic protection, never touch the chips! Most current products use a CMOS (Complementary Metal-Oxide Semiconductor) design, which has practically no resistance to ESD; as little as 30V of ESD can damage CMOS-based devices.

• Hold expansion cards by the brackets, never by the gold edge connectors, chips, or circuitry.

• Wear natural fibers, such as cotton and leather-soled shoes, instead of synthetics, to avoid ESD buildup.

• Use an antistatic spray (commercial or antistatic fabric softener/water mixture) to treat carpeting to reduce ESD.

• Use antistatic cleaning wipes on keyboards, monitors, and computer cases to reduce static buildup. Turn off the power, and if you use a liquid cleaner, always spray the cloth, never the device!

Hazards

Computer equipment and supplies can pose a number of potential hazards for the technician (and, in some cases, for computer users):

• High voltage sources, such as computers, and peripherals, such as printers and monitors

• Mechanical devices, such as printer mechanisms

• Power or data cables running across floors or other locations where users could trip and fall

• Liquids, such as those used for cleaning or refilling inkjet cartridges

• Situational hazards, such as unsafe temporary equipment or cabling locations

• Atmospheric hazards, such as those created by the use of toxic cleaners or the discharge of computer-room-rated fire suppression chemicals

• Moving heavy equipment, such as laser printers, servers, large UPS systems, or print/scan/copy devices

High Voltage Hazards

The number-one hazard created by computer equipment is high voltage that can be present while devices are turned on and plugged in and even when some devices are unplugged and turned off. The major sources of potentially dangerous voltage include

• Printers

• Power supplies

• Monitors

• Systems in suspend or sleep modes

Printers also pose laser and mechanical hazards to technicians. All these risks are covered in the following section.

Printers

Unlike computers, printers normally do not run on safe, low-voltage DC (direct current). Although laser printers typically do use DC current, it is at a high voltage. Most impact and inkjet printers also use high-voltage AC (alternating current).

Any printer should be turned off and unplugged before being serviced. In the event of ink or toner spills, water or other liquids should not be used to clean up the mess unless the printer is turned off and disconnected, due to the risk of a potentially fatal electric shock.

The Power Supply

The exterior of practically every power supply is marked something like this:

CAUTION! Hazardous area! Severe shock hazards are present inside this case. Never remove the case under any circumstances.

See Figure 17-5 for a typical example.

Figure 17-5 Hazard warnings and safety certifications on the label for a typical power supply.

CRT Monitors

As with the power supply, the outside of the monitor is safe. However, if you remove the cover of a CRT monitor for servicing or adjustments, you expose the danger. The high voltage anode (a metal prong covered with a red insulator, found on the wide top of the CRT) holds dangerously high voltage for days after the power is turned off.

Disassembled monitors also pose the following hazards:

• X-rays coming from the unshielded neck of the CRT when the monitor is on

• Dropping the monitor and breaking the CRT

Replace the shielding around the neck of the CRT before using the monitor, and use padding and carefully balance CRTs and monitors during storage and transport to avoid damage. See “Discharging CRTs” later in this chapter for additional information.

Systems in Suspend Mode

Systems based on the ATX, BTX, or NLX standards typically go into a deep suspend mode rather than a true “off” condition when shut down by Microsoft Windows. Some ATX and BTX systems have power supplies with a separate on/off switch on the back of the unit, but some do not. For these reasons, you should disconnect the power cord from the system.

As with other devices, the power can be on unless you disconnect it at the source.

Precautions Against Electric Shock

This section discusses the precautions you should take to avoid the hazards covered in previous sections.

To work with electricity safely, follow these simple precautions:

• Remove jewelry, including rings, bracelets, and necklaces. Metal jewelry provides an excellent path for current.

• Use rubber gloves for extra insulation—rubber gloves prevent your hands from touching metal parts; however, they do not provide sufficient insulation to enable you to work on a live system.

• Work with one hand out of the system if possible, to avoid electricity passing through your chest if your arms complete a circuit.

• Keep your hands and the rest of your body dry; your body’s natural shock resistance drops to virtually nil when your skin is damp.

Regardless of the level of service you will provide to a component, devices such as printers, computers, monitors, and so on should be disconnected from power as well as turned off before service. This will help prevent shock hazards as well as mechanical hazards.

Do not leave the computer plugged in while you work inside it. At one time, an acceptable practice was to leave the computer plugged in but shut down and keep one hand on the power supply as a ground. This is no longer appropriate because ATX, BTX, and other modern computers aren’t really “off”; they’re in a suspend mode and power is still running through memory, expansion cards, and so on.

Discharging CRTs

Do not service CRT-based monitors as a first choice today; most companies are rapidly replacing their remaining CRTs with LCD displays to save power and desk space. You should not service any monitor unless you are a certified technician. However, if you must open a CRT-based monitor for service, discharge the high voltage anode following this procedure:

Step 1. Turn off and unplug the monitor.

Step 2. Remove the housing carefully.

Step 3. Attach a large alligator clip and wire from a long, flat-bladed, insulated screwdriver to the metal frame surrounding the monitor.

Step 4. Slide the flat blade of the screwdriver under the insulator until the tip touches the metal anode clip (see Figure 17-6).

Figure 17-6 Discharging the high voltage anode on a typical CRT. Note the ground wire clipped between the metal monitor frame and the screwdriver.

Step 5. Be prepared for noise—anything from crackling to a loud pop—as the anode discharges its stored electricity. Keep the screwdriver in place for several seconds to fully discharge the anode.

Step 6. Slide the screwdriver out without twisting it; you could damage the CRT.

This process must be repeated after each time the monitor is powered up until the housing is replaced.

Mechanical Hazards

Although computers and their peripherals are primarily electronic and electrical devices, they can pose various mechanical hazards to users, including

• Impact and inkjet printers can pinch or crush fingers in their gears and paper feeders if the cover is removed while the printer is in operation.

• CD and DVD trays can pinch fingers or damage cables when retracting.

• Pins in serial, parallel, VGA, and DVI cable connectors can cause puncture wounds.

• Sharp edges on metal computer cases, card brackets, and drive rails can cause minor cuts.

To avoid mechanical hazards like these, take the following precautions:

• Turn off printers before attempting to remove paper or label jams.

• Follow the manufacturer’s recommended procedure for changing ink cartridges to prevent the printer from attempting to print, move the printhead, or advance paper during the process.

• Make sure fingers, cables, and other potential obstructions are out of the way before closing CD and DVD trays.

• Don’t touch the pins in cable connectors to avoid potential harm to yourself or ESD risks to connected equipment.

• Handle chassis components such as computer cases, card brackets, and drive rails with care. Avoid sliding your hands along the edges of these and similar sheet-metal parts to avoid cuts and scrapes.

• Have antibiotic ointment and appropriate bandages, including finger and knuckle bandages, handy in case of injury to hands or fingers.

Tripping Hazards

Watch out for loose cables! Whether it’s a temporary setup while you are repairing a balky PC or printer or a “permanent” office setup, power or data cables running across floors or other locations where users could trip and fall are accidents waiting to happen. When someone trips or falls because of power or data cables, both the individual and the connected equipment can be harmed.

Avoid trip/fall hazards by controlling cable sprawl. Use the following tools and techniques to manage cables:

• Cable ties are an inexpensive way to keep overlength cables out of the way. They use Velcro or similar hook-and-loop material to provide self-adhesive properties, and come in a variety of colors you can use for color-coding or to assure that the cable tie is the same color as or a contrasting color to the cable. Cable ties are available at electronics and computer stores, as well as fabric and hobby stores.

• To manage bundles of cables running to a particular PC or other equipment, consider cable wraps or cable trappers.

• For temporary cable runs across floors, such as in a repair situation, a trade show, or a training class, use gaffers’ tape or duct tape to tape the cables to the floor. These types of tape leave little or no residue when used for short periods of time and can be used to hold down network, power, video, or other types of cables.

• For long-term cable installations, use cable management systems to keep cables out of the way. These can be as simple as a floor cable concealer, which protects cables on the floor from damage, or as elaborate as cable trays, which carry cables over a suspended ceiling, or cable raceways, which conceal cable runs along wallboards or crown molding. The Cable Organizers website, www.cableorganizer.com, is a good place to start your search for permanent cable organizing solutions.

Liquid Hazards

Liquids, such as those used for cleaning computer equipment or refilling inkjet cartridges, pose a variety of hazards, including

• Electric shock hazard when used to clean ink or toner spills in a printer

• Carpet or clothing stains when refilling inkjet cartridges

To avoid electric shock hazards caused by liquid cleaner, make sure the printer or other component is turned off and unplugged before using a liquid cleaner. To clean up spilled toner, use a toner-rated vacuum cleaner.

To avoid carpet or clothing stains when refilling inkjet printer cartridges, be sure to follow the vendor’s instructions carefully.

Situational Hazards

When you are setting up computer equipment on a temporary basis, such as for a repair or configuration before permanent installation, it might be tempting to take shortcuts that you would not consider for a permanent installation. Watch out for the following:

• Don’t overload a worktable or bench with equipment. If the legs collapse or the tabletop gives way, both you and the equipment could be harmed. Check the rating for the furniture before piling it up with heavy printers, UPS systems, all-in-one units, 19-inch or larger CRT monitors, and similar heavyweights.

• Avoid using chairs, tables, or other surfaces as replacements for stepstools or ladders. You can fall and hurt yourself—and break equipment in the process.

• Don’t use empty boxes as temporary stands for equipment. If you must use boxes until the furniture arrives, use boxes that still contain equipment—and don’t put heavy components atop lightweight boxes.

• Watch out for trip/fall hazards from power and data cables, surge suppressors, and the like. See “Tripping Hazards,” earlier in this chapter, for methods to avoid tripping hazards during short-term computer setups.

Situational hazards can also pose potential threats during permanent computer or peripheral installation:

• Don’t overload tempered-glass desktops or other furniture. These items usually have clearly-marked load limits. Exceed them, and watch the monitors or printers crack the glass as they fall.

• Tag power and data cables to make it easy to tell which cables go with what equipment.

Atmospheric Hazards

The major atmospheric hazard for computer users is the use of Halon in the fire-extinguisher systems of computer rooms. Halon is toxic to humans (it can cause cardiac problems), although it is safe for computer equipment. If you work in a computer room or other area that uses Halon-based fire extinguishers or sprinkler systems, make sure you do not breathe in Halon fumes. Exit the area immediately in case of fire.

DuPont FE-36 is a safe alternative to Halon, providing comparable fire suppressant control for Class A, B, and C fires, while being far less toxic. To learn more about FE-36, see the DuPont FE-36 information page at http://www2.dupont.com/FE/en_US/products/fe36.html.

Heavy Equipment Hazards

Laser printers, workgroup-grade all-in-one units, high-capacity UPS battery backup systems, and servers are potential hazards because of their weight and bulk. Take the following precautions to avoid injury and damage

• Move equipment in its original cartons and packaging whenever possible.

• Use wheeled freight dollies or carts to move equipment.

• Use “team lift” methods to move heavy and bulky items.

• Wear a back brace.

Environmental and Accident Incident Handling

Even with the best of precautions, environmental issues and accidents involving computers and related technologies can and do happen. Use the following procedures to handle problems safely and professionally

• Know who to contact in case of injuries to personnel, damage to equipment, fires, or chemical spills.

• Know how to reach an outside phone line to call 911 in case of serious emergency.

• Review and follow procedures for cleaning up chemical spills, retrieving damaged computer equipment, or other problems.

• Have MSDS information available for computer-related supplies and chemicals.

• Write up the incident in a professional manner, noting time, place, personnel involved, and other important information.

• Work with other personnel to solve problems resulting from the incident.

• Learn from the incident to help avoid future problems.

Exam Preparation Tasks

Review All the Key Topics

Review the most important topics in the chapter, noted with the key topics icon in the outer margin of the page. Table 17-2 lists a reference of these key topics and the page numbers on which each is found.

Table 17-2 Key Topics for Chapter 17

Definitions of Key Terms

Define the following key terms from this chapter, and check your answers in the glossary.

ESD,

MSDS,

AC,

DC,

Suspend mode,

Faraday cage antistatic bags

Troubleshooting Scenario

You are a technician for your company. You walk into work one morning and turn on the lights. You notice that one of your co-workers worked late the night before and left many electrical cables stretched across the floor. What should you do in this scenario?

Refer to Appendix A, “Answers to the ‘Do I Know This Already?’ Quizzes and Troubleshooting Scenarios,” for the answer.