A Plus Study Guide By Domain

Domain 1.0 Installation, Configuration and

Upgrading

Domain focuses on the knowledge and skills necessary to identify, install, configure and
upgrade microcomputer components (Field Replacement Units).

Interrupt Request Settings (IRQ) Settings

The various devices in your computer, such as video, sound cards the items on the motherboard, your modem, etc. and some things that are attached to your computer share system resources.  IRQs are basically signals that are sent from one part of your PC to another indicating that some special action or attention is needed from the processor (CPU).

Each computer has 15 IRQs ranging from 0 to 15 and only one device can use an IRQ at one time.  If more than one device is trying to use an IRQ, then a conflict will occur, meaning one of the devices will cease to function properly.  Listed below are the IRQs and their respective attached devices:

I/O Address Settings

Every device within a PC must have its own unique address, hence I/O settings.  The I/O address points to the location in memory that is assigned to a particular device.  This address is expressed in hexadecimal (h).  Ranges appear below:

Serial Devices and Communication

This process uses RS-232C port standard with DB9 or DB25 to transmits data sequentially over a single conductor either synchronously or asynchronously.

 

Parallel Communication Devices

Transmits data over eight conductors in parallel. Signals are either control signals or data
signals. Control signals are used to synchronize the devices (Handshaking).

 

Types of Connectors

Connectors are either Male (Pins) or Female (sockets).

Serial Ports are Male on the PC (DB9 or DB25)
Parallel Pods are Female on the PC (DB25)
Video is Male on the PC (DB9)
Mini/DIN is Female on the PC (PS/2)

Characteristics of IDE Devices

Integrated Drive Electronics are controllers for Hard Drives. CD-ROMS and any other
compliant device.

• The Controller is on the device itself.
• Early IDE devices had a limitation of 528MB, now hard drives can come as large as 80 Gigabytes
• Uses 40 Pin cables (floppy uses 34)
• The primary drive is considered the Master and any other drive attached is said to be the Slave drive.

SCSI Devices

Small Computer Systems Interface allows you to connect multiple devices to one cable. The
Card is the controller so it removes overhead from the Drive itself and the CPU.

Notes:

• The adapter is always given the ID of 0 on PS/2 machines or ID 7 for most others
• The first hard disk is ID 1 on PS/2 and ID 0 for most others
• CD-ROM devices are ID 3
• Slower devices are given slower ID's
• Internal SCSI uses 50 pin ribbon connectors
• External cables are female DB-25, Centronics 50, mini-50, or mini-68
• Both ends of the cable must be terminated

Some devices have inbuilt termination which can be set via jumpers.


BIOS

The Basic Input-Output System (BIOS):

• Contains the system settings for the computer
• Is stored on Read Only Memory (ROM) on a memory chip located on the motherboard
• The settings are removed from BIOS when you turn the computer off, but are restored from the CMOS (Complimentary metal Oxide Semi-Conductor) at boot time
• The CMOS is powered by the battery
• Flash BIOS means that the BIOS can be upgraded via a software Flash Program from the
  BIOS vendor
• Removable BIOS means that to Upgrade you have to physically remove and replace the
  BIOS chip

 

Domain 2.0 Diagnosing and Troubleshooting

This domain deals with diagnosing and resolving various FRU problems

POST Audible / Visible Error Codes

The Power On Self Test occurs every time you boot (turn on) your computer. Its purpose is to help diagnose system related problems that are found in hardware or BIOS.  In most cases, anything other than a single beep indicates a fault or problem.

Common Error Codes

 

Domain 3.0 Preventive Maintenance

This domain is concerned with preventive maintenance, safety and disposal requirements.

Cleaning

• Liquid cleaning compounds such as isopropyl alcohol can be used to clean contacts and
  read/write heads via a cleaning diskette
• Rubber knives can be used to remove hardened residue. metal knives should never be used
• Always vacuum out the case whenever you get the chance to reduce the build up of dust and also static electricity.

Power Issues

• Brownouts occur when there is not enough power to operate an electrical device
• Power Spikes are huge increases in electrical current for a split second
• Power Surge are similar to a spike but lower power

UPS

A UPS protects your PC from brownouts, spikes, surges and dirty current. This is
accomplished by several components in the UPS such as suppressers. noise filters, and
surge protectors.  Suppressers - Absorbs or blocks the spike and protects against surges.
Noise Filters - Noise caused by Electro-Magnetic Interference (EMI) is reduced


Monitors (CRT)

Monitors are high voltage components. Never wear an ESD wrist strap when handling
monitors. To discharge a monitor, connect a wire around the screwdriver and ground the wire. Use the screwdriver to pry the anode lead from the back of the CRT.


Disposal Procedures

Electro-Static Discharge

This can cause catastrophic damage where the device is inoperable or it can cause
degradation in a component which may still perform.  Hidden ESD is a static discharge that you can not feel. You only feel ESD above 30,000 volts however components can still be damaged below 30.000 volts.

To protect against ESD you should use anti-static mats, bags and an ESD wrist strap. You can
ground the wrist strap to the earth pin on a wall socket.  Make sure that you also remove all metallic jewelry.  Also bear in mind, that "Humidity below 50% leads to static".

 

Domain 4.0 Motherboard / Processors /

Memory

This domain is concerned with terminology and classifications of hardware.

CPU Chips

8088
Used an 8-bit bus and ran at 4.77Mhz

386
Could handle up to 16MB of memory.
3868X had a l6bit data bus and operated at 16.20,25, and 33MHz
386DX had a 32bit data bus and operated at 16,20,25, and 33MHz

486
Four types the SX, DX, DX2 and DX4.
The bus for all is 32bit. An 8bit on chip cache was introduced.  Also, a Math Co-Processor was
in-build but disabled on the SX.

586 (Pentium Class)
64b1t data bus, l6bit cache. Combines two 486DX chips into one using the Dual Independent
Bus Architecture resulting in true parallel processing. Heat sinks were required due to the
large amount of heat generated.

686 (Pentium II Class)
Integrated MMX technology.
Uses Slot 1 instead of a socket

Microprocessor Characteristics

Random Access memory (RAM)

Static RAM (SRAM)
SRAM doesn't have to be constantly refreshed. Uses a lot of power. Used in old IBM XI
machines and was limited to 2561< per chip.

Dynamic RAM (DRAM)
DRAM use capacitors instead of transistors and switches. Needs constant refresh.

Windows RAM (WRAM)
Specific to speed up graphical windows operations.

Extended Data Output RAM (EDO RAM)
Has a cache on the chip and is 10-15% faster Than DRAM. Requires a special motherboard.

Memory comes in 30 or 72 pin SIMMs or 168 pin DIMMS


Bus Architectures

Industry Standard Architecture (ISA)
This was introduced on AT computers.
Allowed a 1 6-bit data bus.
Used in 266 and 3865X PC's

Extended Industry Standard Architecture (EISA)
Introduced to compete against IBM's MCA.
Uses a 32-bit data bus.
Used in 386DX and 486 PCI

Peripheral Component Interconnect (PCI)
Designed to use Pentium Processors
Uses a 64-bit data bus.
Uses a bridge circuit to be processor independent.

Universal Serial Bus (USB)
A new technology for Plug and Play devices allowing up to 12Mbps and up to 127 simultaneous connections.

VESA Local Bus (VL_Bus)
Used for Video cards on top of EISA, a very long video card.

Personal Computer Memory Card International Association (PCMCIA)
Now called PC Card.
Used in Laptops.
Currently only 16-bit data bus

Domain 5.0 Printers

This domain requires knowledge of basic types of printers, concepts and how they work.

Main components of a laser printer are:

Electro photographic Print Process (EP)

The process concerned with putting the image on the page. Follows Six steps:

Troubleshooting Printers

 

Domain 6.0 Basic Networking

Coming Soon

 

 

 

 

 

Home | About Us | Legal Stuff | Contact Us | External Links | Sitemap
Copyright | 2001-2010 AUNJAR, LLC - All Rights Reserved