Computer Hardware Basics Basic Electronics, PC Maintenance, Upgrade and Repair

Computer Hardware BasicsComputer Hardware Basics

Basic Electronics, PC Maintenance, Basic Electronics, PC Maintenance, Upgrade and RepairUpgrade and Repair

Computer TypesComputer Types

Personal computers Personal computers typically come in one of typically come in one of three styles . . . .three styles . . . .The “desktop.” The The “desktop.” The original computer, not original computer, not nearly as popular as it nearly as popular as it used to be . . . .used to be . . . .The “tower.” The choice The “tower.” The choice of most consumers . . . .of most consumers . . . .And the laptop. Portable, And the laptop. Portable, convenient, and very convenient, and very difficult to work on.difficult to work on.

Hardware - Hardware -

The power supply converts the The power supply converts the 120VAC from the wall outlet to 120VAC from the wall outlet to DC voltage levels used by the DC voltage levels used by the various computer components.various computer components.

These voltages are typically These voltages are typically 3.3V, 5V and 12V DC.3.3V, 5V and 12V DC.

These voltages are used by These voltages are used by the motherboard, disk drives, the motherboard, disk drives, expansion cards, etc.expansion cards, etc.

Power Supply Power Supply


A rectangular piece of circuit A rectangular piece of circuit board covered with many board covered with many conductors. Called a conductors. Called a “computer bus.” This bus “computer bus.” This bus provides . . . .provides . . . .

Electrical energy paths to the Electrical energy paths to the computer components and computer components and expansion slots,expansion slots,

A way to distribute the digital A way to distribute the digital signals carrying data, control signals carrying data, control instructions,instructions,

And small amounts of And small amounts of electrical power to the many electrical power to the many different components mounted different components mounted on the board.on the board.

Motherboard Motherboard


Also called the internal drive or Also called the internal drive or hard disk.hard disk.

The location where all computer The location where all computer programs and data are stored.programs and data are stored.

Made up of several disks (often Made up of several disks (often called platters) stacked inside a called platters) stacked inside a sealed box.sealed box.

Data and programs are stored Data and programs are stored on the hard drive as on the hard drive as magnetic magnetic impulsesimpulses..

It is connected to the power It is connected to the power supply by a wire harness made supply by a wire harness made up of several different colored up of several different colored wireswires

Hard DriveHard Drive


Data is transmitted to and from Data is transmitted to and from the hard drive through a flat the hard drive through a flat parallel ribbon cable connected parallel ribbon cable connected between the drive and the between the drive and the motherboard.motherboard.

Newer systems of today are Newer systems of today are using smaller serial cables to using smaller serial cables to perform this function.perform this function.

Hard DriveHard Drive


Acronym for “Central Acronym for “Central Processing Unit.” It is the Processing Unit.” It is the microprocessor and the brain microprocessor and the brain of the computer.of the computer.

Contains millions of Contains millions of microscopic electronic microscopic electronic components called components called transistorstransistors..

The transistors are electrically The transistors are electrically connected in such a way that connected in such a way that they can interact with they can interact with computer programs and computer programs and process data.process data.

CPU CPU


The CPU controls the data in the The CPU controls the data in the computer.computer.

Commands are issued to the CPU Commands are issued to the CPU via software and it translates the via software and it translates the commands into actions.commands into actions.

The CPU does not think or The CPU does not think or possess human intelligence. It possess human intelligence. It simply carries out the program simply carries out the program codes written in the software codes written in the software program.program.

CPU CPU


Acronym for “Random Access Acronym for “Random Access Memory.”Memory.”

It is the location where computer It is the location where computer programs are loaded from the programs are loaded from the hard drive.hard drive.

Is classified as Is classified as volatilevolatile memory, memory, which means that the data and which means that the data and programs loaded in it are lost programs loaded in it are lost when computer power is turned when computer power is turned off.off.

Usually mounted in several Usually mounted in several parallel slots on the parallel slots on the motherboard.motherboard.

RAM RAM


RAM is a place where data is RAM is a place where data is temporarily stored. It is emptied temporarily stored. It is emptied when the computer turns off.when the computer turns off.

When the PC is turned back on, When the PC is turned back on, new information is loaded into new information is loaded into the RAM.the RAM.

RAM RAM


BIOS is acronym for “Basic BIOS is acronym for “Basic Input/Output System.Input/Output System.

Stored in a special kind of Stored in a special kind of memory chip called an EEPROM, memory chip called an EEPROM, formerly just a PROM.formerly just a PROM.

Consists of software programs Consists of software programs that support the compatibility that support the compatibility between the CPU and devices like between the CPU and devices like the hard drive, CD-ROM drive and the hard drive, CD-ROM drive and the monitor.the monitor.

BIOS can be updated by “flashing” BIOS can be updated by “flashing” the EEPROM with the updated the EEPROM with the updated BIOS program.BIOS program.

BIOS and CMOSBIOS and CMOS

BIOS and CMOSBIOS and CMOSHardware - Hardware - CMOS is an acronym for CMOS is an acronym for “complimentary metal oxide “complimentary metal oxide semiconductor”, which describes semiconductor”, which describes the electronic technology to the electronic technology to construct the chip (integrated construct the chip (integrated circuit).circuit).BIOS setup information is stored BIOS setup information is stored in the CMOS chip. Information in the CMOS chip. Information such as the date and time, as well such as the date and time, as well as information about the as information about the computer’s hardware.computer’s hardware.A battery on the motherboard is A battery on the motherboard is used to hold the information in used to hold the information in CMOS even after the computer is CMOS even after the computer is turned off.turned off.


Expansion cards are often Expansion cards are often called called interface cardsinterface cards or or host host adaptersadapters..

They allow the computer to be They allow the computer to be custom-designed to meet the custom-designed to meet the needs of different consumers.needs of different consumers.

It may allow upgrade from a It may allow upgrade from a less capable motherboard less capable motherboard integrated circuitry.integrated circuitry.

The expansion cards fit into The expansion cards fit into slots on the motherboard. slots on the motherboard. Typical types of slots are Typical types of slots are ISA, ISA, EISA,EISA, and and PCI PCI..

Expansion Cards Expansion Cards

Audio Card

NetworkCard

VideoCard


Cooling fans provide a constant Cooling fans provide a constant stream of air across the computer stream of air across the computer components.components.

The typical CPU comes with a fan The typical CPU comes with a fan mounted directly on top of it to mounted directly on top of it to assist in the cooling process.assist in the cooling process.

Heat KILLS! Electronic Heat KILLS! Electronic components are damaged or components are damaged or destroyed by excessive heat.destroyed by excessive heat.

Cooling FansCooling Fans


Cables connect all of the Cables connect all of the computer systems together.computer systems together.

There are many different types There are many different types of cables inside a PC.of cables inside a PC.

Flat ribbon cables are used to Flat ribbon cables are used to connect the motherboard to the connect the motherboard to the hard drive, CD-ROM drive and hard drive, CD-ROM drive and floppy drive.floppy drive.

Flat ribbon cables consist of Flat ribbon cables consist of many parallel conductors many parallel conductors covered in insulation.covered in insulation.

Today’s hard disk drives use Today’s hard disk drives use SATA cables instead of parallel SATA cables instead of parallel ribbon cables.ribbon cables.

CablesCables


Higher levels of electrical Higher levels of electrical power can’t run through power can’t run through ribbon cable. Therefore, ribbon cable. Therefore, separate wiring harnesses separate wiring harnesses from the power supply are from the power supply are used.used.

There are also a lot of There are also a lot of external cables used to external cables used to connect various connect various peripheral devices.peripheral devices.

CablesCables


Floppy Drives – a floppy drive Floppy Drives – a floppy drive reads and writes to a 1.44MB reads and writes to a 1.44MB magnetic floppy disk. It stores magnetic floppy disk. It stores small amounts of data.small amounts of data.

CD-ROM Drive – (Compact Disk CD-ROM Drive – (Compact Disk Read Only Memory Drive) A drive Read Only Memory Drive) A drive that can read large amounts of that can read large amounts of data from a CD-ROM using a data from a CD-ROM using a laser beam of light. laser beam of light.

DVD Drive – (Digital Versatile DVD Drive – (Digital Versatile Disk Drive) A drive that reads data Disk Drive) A drive that reads data from a DVD using a laser beam of from a DVD using a laser beam of light. DVD offers the highest light. DVD offers the highest storage capacity of all laser-based storage capacity of all laser-based CD’s thus far.CD’s thus far.

Other DevicesOther Devices

Electrostatic DischargeElectrostatic Discharge

Abbreviated “ESD”, is best defined in the world of Abbreviated “ESD”, is best defined in the world of computer maintenance as the transfer of static computer maintenance as the transfer of static electrical energy from one object to another.electrical energy from one object to another.Usually created by friction.Usually created by friction.

When two dissimilar materials are rubbed together, an When two dissimilar materials are rubbed together, an electric charge is produced.electric charge is produced.

Integrated circuits (IC’s) in a computer are very small, Integrated circuits (IC’s) in a computer are very small, and made of material that is very susceptible to ESD.and made of material that is very susceptible to ESD.

The electrostatic discharge will damage (destroy) the The electrostatic discharge will damage (destroy) the IC.IC.

Electrostatic DischargeElectrostatic Discharge

To avoid ESD, technicians wear a ground strap when handling static To avoid ESD, technicians wear a ground strap when handling static sensitive devices.sensitive devices.

The anti-static wrist strap bleeds off any static charge buildup on a The anti-static wrist strap bleeds off any static charge buildup on a technician’s body and sends it to ground..technician’s body and sends it to ground..

Also, when working with static sensitive material outside of the PC Also, when working with static sensitive material outside of the PC case, a static “mat” should be used. It works similarly to the wrist case, a static “mat” should be used. It works similarly to the wrist strap.strap.

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Computer Hardware Basics Basic Electronics, PC Maintenance, Upgrade and Repair