Chapter 3
EXAM OBJECTIVES
Gathering the tools of the trade
Understanding ESD and EMI
Personal safety and high-voltage equipment
Disposing of components
Understanding ergonomics
Before addressing how to install computer components such as memory, processors, or a hard drive, you want to make sure that you understand the risks that are involved every time you take the cover off the computer. On the A+ Exams, CompTIA will be sure to test your knowledge on how to safely handle a computer’s electronic innards and how to safely and legally dispose of broken or obsolete parts.
In this chapter, I discuss ESD (electrostatic discharge) and EMI (electromagnetic interference), as well as what high-voltage equipment is and why you should stay away from these components. I also show you how to dispose of computer components, and then introduce you to ergonomics.
When plumbers or electricians come to your house to do some work, they bring a toolbox containing what they need to fix most problems that might arise while on the job. As an A+ Certified Professional, you need to do the same thing: Keep a PC repair toolkit of all the tools — software and hardware — that you need to do your job.
The following sections discuss the hardware and software tools that you need to perform your job well.
Of the myriad pieces of hardware you need to repair computers, the most popular is the humble screwdriver. You can purchase a PC repair toolkit (shown in Figure 3-1) at your local computer store, but you should be able to get away with a multihead screwdriver for most jobs.
The following is a list of tools that you might need from time to time to fix most of your computer repair problems:
Screwdrivers: Most toolkits come with a variety of screwdrivers that have a variety of tip shapes and sizes — flat-head screwdrivers with a flat tip, Phillips screwdrivers with a +-shaped tip, and TORX screwdrivers with a star-shaped tip. I usually use a multihead screwdriver instead of choosing from a mass of different screwdrivers.
Be sure that you don’t use a magnetic screwdriver on the computer because you could erase your data!
Most technicians think of hardware tools when they think of tools of the trade, but software tools are important, too. I give you in-depth information about the software tools you need in your PC repair toolkit in Book 6, Chapter 4, but I want to introduce them here so you get a more complete listing of the tools you will use in the field:
In this section, I discuss the dangers of servicing a system without taking precautions as to not damage the computer or hurt yourself. Be sure to take this section very seriously!
When you walk around on carpet, scuffing your feet, you build up a static charge. You walk over to your best friend, touch his or her hand, and zap! — an explosive shock! You feel that static shock because you have a higher static charge than your friend. When two objects with dissimilar charges touch, the excess electrons are transferred to the object with the lesser charge. This is when you feel the shock.
The scary part about all of this is that in order for you to feel the shock, you must have a charge of approximately 3,000 volts (V), but only about 200V are needed to kill a computer chip — and just 30V can do long-term damage to a chip.
Transference of static charge to another object — electrostatic discharge (ESD) — is responsible for damaging or killing computer components, such as computer chips. It is your job as an A+ Certified Professional to make sure that you eliminate ESD by following ESD best practices.
When handling computer equipment, it is critical that you know how to handle computer components to prevent the destruction of the equipment with ESD. You can reduce ESD, but because ESD occurs naturally, you can never completely get rid of the static buildup you carry with you. To reduce your chances of damaging a system when servicing a computer, follow these best practices:
ESD straps: One of the most popular solutions for preventing damage to computer components is to wear a grounding strap (shown in Figure 3-3), which is also known as an ESD wrist strap. The grounding strap goes around your wrist and contains a resistor that absorbs any static electricity. The wrist strap then clamps to the metal chassis — the casing — of the computer. This gives you constant grounding while servicing the computer, eliminating any static buildup.
If you don’t have a grounding strap to connect to the chassis of the computer, be sure to constantly eliminate any static electricity that has built up on yourself by touching the chassis before touching any computer part. Keep in mind that you should always disconnect the power from the computer before working on it.
A number of people confuse ESD with electromagnetic interference (EMI), which involves computer equipment receiving electrical interference from an outside source, such as another electrical device or a piece of machinery.
Although ESD often causes permanent damage (if you fry a computer chip, it is damaged permanently), EMI is, for the most part, temporary. For example, if you notice that your monitor display is distorted because you are getting interference from an outside source, moving the monitor away from the external source should get the monitor back to normal.
That being said, EMI exposure for a long period of time can cause permanent damage to computer components.
Before continuing into the world of computer repair, it is important for you to follow some basic safety rules. In the following sections, you find out about some basic rules to follow when servicing computers, but you also discover high-voltage equipment you should stay away from unless you are properly trained to service those components.
You should always follow a number of guidelines when servicing the computer. These guidelines ensure your safety by preventing the chances of you getting electrocuted. Keep the following in mind when you crack the cover of a computer open:
High-voltage equipment can cause serious injury if you touch it — it might even kill you. You will not typically service these two major computer components unless you have special training or certification beyond the A+ Certification Exams:
High-voltage equipment usually bears a warning label that indicates that you shouldn’t open the component — and, that if you do, you could be severely hurt. Bottom line: You’re playing with fire (all right, electricity) if you open these components. Have them serviced by a certified electrician or someone with special training.
The power supply unit (PSU) is responsible for taking alternating current (AC) from the wall outlet and converting it to a direct current (DC) that is usable by computer components.
The power supply usually takes 120V of alternating current from the wall outlet and supplies the power to computer components by converting the 120 volts AC into 3.3V, 5V, or 12V of DC.
The power supply contains a charge even after it is unplugged, so servicing a broken power supply is not recommended. If your power supply is broken, just replace it.
If you end up in a situation where you are asked to service an old CRT monitor, please beware! The part of the monitor that you need to be aware of is the cathode ray tube itself. Creating the images on a CRT monitor takes a lot of power — typically 50,000V, which is enough to cause yourself serious harm, if not kill yourself. Remember that this charge is held even when the monitor is unplugged from the wall: As a general rule, do not open the monitor unless you are a qualified professional (and remember that passing the A+ Exams doesn’t qualify you to work with CRTs).
Slip the end of the shorting probe under the rubber grommet (looks like a little rubber flap).
Make sure that you don’t touch any other metal parts. You should hear loud popping noises as the high-voltage equipment is discharged.
After you have dealt with the safety concerns dealing with yourself, you can then turn your focus to protecting the computer components! The following are some guidelines to know for the A+ Certification Exams regarding protecting computer components:
When you replace an old part from a computer, you have a responsibility to dispose of the old part properly. You are not permitted to dump certain computer components in a landfill because they are hazardous to the environment. For example, the chemicals in a battery could leak into the water supply and contaminate the drinking water. In this section, you find out how to dispose of certain computer components that can be dangerous to the environment.
Federal and local laws regulate the disposal of hazardous materials; if you break these laws, you could be fined. If you’re unsure how to dispose of a certain component, contact your state or province environment regulator office to find out how to appropriately dispose of it. You should also watch for organizations such as schools, universities, and sometimes businesses hosting a recycling drive that allows you the opportunity to get rid of old computer equipment.
You can also contact the U.S. Environmental Protection Agency (EPA) for proper procedures and guidelines on how to safely dispose of computer components. These guidelines are also published on the EPA web page at www.epa.gov/epawaste/conserve/materials/ecycling/index.htm
.
Because batteries contain metals that are environmentally harmful (such as nickel and cadmium), federal, state, and local laws prevent people from dumping their batteries in trash cans and throwing them to the curb destined for a landfill. The federal government passed the Battery Act in 1996 to ensure that the public properly disposes of rechargeable batteries and batteries that contain mercury. You can find information about the Battery Act by checking out www.epa.gov/wastes/conserve/materials/ecycling
.
Each state has different regulations and rules that deal with the disposal of batteries, and you should be sure that you follow these rules when disposing of old batteries. Contact your state’s environmental regulatory office for more information on disposal of batteries and other computer components.
Because CRTs contain harmful components, they cannot be dumped in landfills. You can donate old monitors that are still in working condition to public schools, churches, and charities. With any donation, you may get a tax benefit! If the monitor doesn’t work or is so badly damaged that it can’t be given away, you can contact recycling companies that will take it off your hands and use it for spare parts.
A number of vendors offer a small discount if you turn in old toner kits or cartridges when you buy new ones. Even if they don’t give a small discount, at least they’ll take the old toner off your hands. These vendors typically send the old toner kit or cartridge back to the manufacturer to be recycled.
If the vendor you purchase from doesn’t take the used toner kits and cartridges, you should contact the manufacturer and find out how you can dispose of them. If you don’t want to contact the manufacturer, you can always check with your state’s environmental regulatory office.
A Material Safety Data Sheet (MSDS) contains information about hazardous chemicals present in different materials. The MSDS contains the composition of these materials and includes their ingredients so that you will know what makes up a particular material.
The MSDS also contains information on the proper handling of materials and the lethal doses for each material. You can obtain information on MSDS by visiting www.osha.gov
and running a search for “MSDS” and your material.
Computers do a lot of great things. They crunch thousands of numbers and process data at phenomenal rates; they perform tedious, repetitive actions without complaining; and they allow a thousand-page book like this one to be written, edited, and proofread without using a single sheet of paper. Unfortunately, working on a computer can cause health problems. Ergonomics is the study, or science, of designing equipment that reduces discomfort for the user and reduces or prevents repetitive strain injury (RSI).
RSI is an injury to the muscles and tendons in the neck, shoulders, arms, wrists, and/or fingers caused by the poor posture and frequent repetitive movements that accompany long hours in front of a computer. Some common examples of RSI are carpal tunnel syndrome, tenosynovitis, and tendonitis. Here are some recommendations you can follow to help reduce discomfort and RSI:
This chapter highlights a number of safety issues surrounding the servicing and using of computer systems. The following is a quick review of some of the key points to remember from this chapter:
1. Which of the following is considered high-voltage equipment? (Select all that apply.)
(A) Printers
(B) CRTs
(C) Power supply units
(D) Hard drives
2. Computer components can be destroyed with as little as
(A) 3,000 volts
(B) 200 volts
(C) 500 volts
(D) 900 volts
3. Your manager has asked you to take some of the memory out of a system located on the fourth floor and to put it in Jill’s computer, which is located on the tenth floor. Which of the following should you use to store the memory module while transporting it to Jill’s workstation?
(A) ESD strap
(B) ESD mat
(C) Safety googles
(D) Antistatic bag
4. Your organization has a number of hazardous materials on site. Your safety manager wants to ensure that the company knows how to handle and dispose of these materials. What should you use?
(A) ESD strap
(B) MSDS
(C) ESD mat
(D) Safety googles
5. EPA stands for
(A) Environmental Protection Association
(B) Environmental Protection Agency
(C) Environmental Preservation Agency
(D) Environmental Preservation Association
6. RSI stands for
(A) Restive strain injury
(B) Repetitive self-injury
(C) Restrictive system injury
(D) Repetitive strain injury
7. The static shock one commonly feels is typically about how many volts?
(A) 3,000
(B) 200
(C) 10
(D) 5
8. You can prevent damage from ESD by
(A) Keeping the air dry
(B) Using a multimeter
(C) Using a grounding wrist strap
(D) Using a TORX screwdriver