TOPIC A
Tools of the Trade
In the last lesson, you learned the basics of operating systems. Knowing what tools are required for certain activities is another important part of an A+ technician’s knowledge base. In this topic, you will identify common hardware and software tools used by professional per- sonal computer technicians.
Having the right tool will save you time, trouble, and expense, but you won’t usually know what you need until you get to the site. A good collection of software and hardware tools (kept ready to use) will make your life much easier. In this topic, you’ll learn what tools you should assemble in toolkits for specific types of jobs.
Multimeters Definition:
A multimeter is an electronic instrument used to measure voltage, current, and resistance. It usually has two wires, one red and one black, that are plugged into two sockets on the meter. The socket you use might depend on what you want to measure. Digital meters have a screen that displays the numeric value of what you are measuring. Analog meters have a thin needle that swings in an arc and indicates the value of what you are measuring.
A loopback plug is a special connector used for diagnosing transmission problems that redi-
rects electrical signals back to the transmitting system. It plugs into a port and crosses over the
transmit line to the receive line. Loopback plugs are commonly used to test Ethernet NICs.
A software diagnostic tool or utility is a computer repair program that can analyze hardware
and software components and test them for problems. Some software diagnostic tools can
repair software problems and optimize settings. Most operating systems include several soft-
ware diagnostic tools, and computer stores generally have an aisle dedicated to utility software
developed by other software manufacturers.
Firmware is software stored in memory chips that retains data whether or not power to the
computer is on. It is most often written on an electronically reprogrammable chip so it can be
updated with a special program to fix any errors that might be discovered after a computer is
purchased, or to support updated hardware components.
A Basic Input/Output System (BIOS) is a set of instructions that is stored in Read Only
Memory and that is used to start the most basic services of a computer system. Every com-
puter has a system BIOS, which sets the computer’s configuration and environment when the
system is powered on. It is located on the system board. Computers can have more than one
BIOS to control other system functions.
Some of the common methods to access system setup are displayed in the following table.
CMOS RAM
Definition:
Complementary Metal Oxide Semiconductor RAM (CMOS RAM) is special memory that has its own battery to help it keep track of its data even when the power is turned off. CMOS RAM stores information about the computer setup that the system BIOS refers to each time the com- puter starts. Because you can write new information to CMOS RAM, you can store information about system changes, such as new disk drives that you add to your system. The computer will look for the drive each time it is turned on.
Prior to the use of CMOS, system settings were configured with jumpers and switches. CMOS
was introduced with the AT system boards. Newer computers have CMOSs that allow for more
configuration options than the switches and jumpers—or even earlier CMOSs—did, primarily
because they use an extended CMOS memory area called the Extended System Configuration
Data (ESCD) to hold information about specific hardware devices. Any time you change a
hardware component, you should check the CMOS settings to see if they also need to be
changed for the system BIOS to recognize the new hardware. Also, you can configure CMOS
without needing to open the chassis. The extent to which you can use CMOS to configure a
computer depends heavily on the manufacturer of the particular CMOS; however, in most
cases, you should be able to configure at least the following—and possibly much more—from
the keyboard by using the CMOS Setup program.
The POST process contains several steps to ensure that the system meets the necessary
requirements to operate properly.
Here are just a few examples of applicable software diagnostic tests.
Static electricity is a build-up of a stationary electrical charge on an object. It is called static
because the charge cannot escape the charged body, but it remains still.
If 120 V from a household electrical outlet can kill you, why does a static spark of 20,000 V
just startle you? Because, while the voltage might be high, the current is very low; very few
total electrons are transferred in a static spark. All the energy of all the electrons in a spark
added together cannot hurt you, even though it may surprise you. Each electron in a static dis-
charge has extremely high energy, but the human body is just too big for the very small
number of electrons involved in the spark to cause widespread damage. A few cells in your
fingertip may be damaged, but they easily grow back.
Electrostatic discharge (ESD) occurs when a circuit is created that allows electrons to rush
from a statically charged body to another with an unequal charge. The electricity is released
with a spark. The charge follows the path of least resistance, so it can occur between an elec-
trical circuit ground, such as a doorknob or a computer chassis, and a charged body, such as a
human hand. ESD can damage sensitive computer equipment.
Tools of the Trade
In the last lesson, you learned the basics of operating systems. Knowing what tools are required for certain activities is another important part of an A+ technician’s knowledge base. In this topic, you will identify common hardware and software tools used by professional per- sonal computer technicians.
Having the right tool will save you time, trouble, and expense, but you won’t usually know what you need until you get to the site. A good collection of software and hardware tools (kept ready to use) will make your life much easier. In this topic, you’ll learn what tools you should assemble in toolkits for specific types of jobs.
Multimeters Definition:
A multimeter is an electronic instrument used to measure voltage, current, and resistance. It usually has two wires, one red and one black, that are plugged into two sockets on the meter. The socket you use might depend on what you want to measure. Digital meters have a screen that displays the numeric value of what you are measuring. Analog meters have a thin needle that swings in an arc and indicates the value of what you are measuring.
Loopback Plugs
Definition:
Definition:
Software Diagnostic Tools
Definition:
Firmware
Definition:
Definition:
The System BIOS
Definition:
Definition:
The System BIOS and System Startup
On startup, the BIOS tests the system and prepares the computer for operation by querying its configuration settings. It searches for other BIOSs on any adapter cards and configures access to those routines. It then loads the operating system and passes control to it. The BIOS accepts requests from the drivers as well as the application programs.
Accessing the System BIOS
Each BIOS manufacturer has its own method to enable users to access system setup menus and configure BIOS settings. A system setup prompt usually appears while the system is boot- ing; for many manufacturers, it is only displayed during a cold boot. The key or key combination you need to press varies between different BIOS manufacturers. You often need to be very quick to catch it and press the appropriate key or keys. Also, sometimes while the monitor is warming up, the message can pass, so turn the monitor on first if you need to access the BIOS.
On startup, the BIOS tests the system and prepares the computer for operation by querying its configuration settings. It searches for other BIOSs on any adapter cards and configures access to those routines. It then loads the operating system and passes control to it. The BIOS accepts requests from the drivers as well as the application programs.
Accessing the System BIOS
Each BIOS manufacturer has its own method to enable users to access system setup menus and configure BIOS settings. A system setup prompt usually appears while the system is boot- ing; for many manufacturers, it is only displayed during a cold boot. The key or key combination you need to press varies between different BIOS manufacturers. You often need to be very quick to catch it and press the appropriate key or keys. Also, sometimes while the monitor is warming up, the message can pass, so turn the monitor on first if you need to access the BIOS.
CMOS RAM
Definition:
Complementary Metal Oxide Semiconductor RAM (CMOS RAM) is special memory that has its own battery to help it keep track of its data even when the power is turned off. CMOS RAM stores information about the computer setup that the system BIOS refers to each time the com- puter starts. Because you can write new information to CMOS RAM, you can store information about system changes, such as new disk drives that you add to your system. The computer will look for the drive each time it is turned on.
CMOS Settings
The Power-On Self Test (POST)
The Power-On Self Test (POST) is a built-in diagnostic program that is run every time a per- sonal computer starts up. The POST checks your hardware to ensure that everything is present and functioning properly, before the system BIOS begins the operating system boot process.
The Power-On Self Test (POST) is a built-in diagnostic program that is run every time a per- sonal computer starts up. The POST checks your hardware to ensure that everything is present and functioning properly, before the system BIOS begins the operating system boot process.
Hard Drive Self Tests
Most hard disk drive manufacturers provide a diagnostic tool that enables the drive to test itself when a personal computer is started up. Some of these hard drive self-tests are built into the firmware for the hard disk drive, while others are separate utilities that are available for download from the drive manufacturer’s website. Make sure that you download the specific test utility for your hard disk drive.
Software Diagnostics Tests
Software diagnostics tests are available from many different manufacturers, and they vary widely in their capabilities, but they can all assist you in detecting, repairing, and preventing hardware and software problems. The Windows operating systems also come with their own sets of diagnostic tools that may help you to detect problems.
Examples of Software Diagnostic Tests
Most hard disk drive manufacturers provide a diagnostic tool that enables the drive to test itself when a personal computer is started up. Some of these hard drive self-tests are built into the firmware for the hard disk drive, while others are separate utilities that are available for download from the drive manufacturer’s website. Make sure that you download the specific test utility for your hard disk drive.
Software Diagnostics Tests
Software diagnostics tests are available from many different manufacturers, and they vary widely in their capabilities, but they can all assist you in detecting, repairing, and preventing hardware and software problems. The Windows operating systems also come with their own sets of diagnostic tools that may help you to detect problems.
Examples of Software Diagnostic Tests
TOPIC B
Electrical Safety
In the last topic, you identified hardware tools used by personal computer technicians. Some of these tools are used to promote electrical safety. In this topic, you will identify the best prac- tices for personal computer technicians to follow to promote electrical safety.
The most prevalent physical hazards that computer technicians face are electrical hazards. Although it is necessary to run a computer, electricity can damage computer equipment, and in some cases, pose a danger to humans. Observing best practices with regard to electrical safety will protect both computer equipment and human lives.
Static Electricity Definition:
In the last topic, you identified hardware tools used by personal computer technicians. Some of these tools are used to promote electrical safety. In this topic, you will identify the best prac- tices for personal computer technicians to follow to promote electrical safety.
The most prevalent physical hazards that computer technicians face are electrical hazards. Although it is necessary to run a computer, electricity can damage computer equipment, and in some cases, pose a danger to humans. Observing best practices with regard to electrical safety will protect both computer equipment and human lives.
Static Electricity Definition:
Sources of Static Electricity
Static electricity is often caused by friction; rubbing one object against another causes a trans- fer of electrons between the two. Using friction to create a static charge is called triboelectric generation. The amount of static that can be built up in this manner depends on various fac- tors, including the types of materials, their surface area and texture, and the ambient humidity. If you have ever rubbed a balloon on your head and stuck it to the wall, you have used triboelectric generation.
Static Electricity and Voltage
Because air has very high resistance, static electric discharge usually requires contact with the statically charged object. For a static discharge to arc through the air, it requires a very high voltage, and no other path to the ground with lower resistance. You can feel a static discharge starting at around 3,000 V. The drier the air, the greater the resistance, which is why static shocks on dry winter days can fall within the range of 10,000 to 20,000 volts. Keeping a room humidified is one way to reduce the risk of static electricity.
Static electricity is often caused by friction; rubbing one object against another causes a trans- fer of electrons between the two. Using friction to create a static charge is called triboelectric generation. The amount of static that can be built up in this manner depends on various fac- tors, including the types of materials, their surface area and texture, and the ambient humidity. If you have ever rubbed a balloon on your head and stuck it to the wall, you have used triboelectric generation.
Static Electricity and Voltage
Because air has very high resistance, static electric discharge usually requires contact with the statically charged object. For a static discharge to arc through the air, it requires a very high voltage, and no other path to the ground with lower resistance. You can feel a static discharge starting at around 3,000 V. The drier the air, the greater the resistance, which is why static shocks on dry winter days can fall within the range of 10,000 to 20,000 volts. Keeping a room humidified is one way to reduce the risk of static electricity.
Electrostatic Discharge (ESD)
Definition:
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