1Hardware. Maintenance ,Trouble Shooting & Networking.ppt

Computer Hardware , Basic Maintenance and Networking

Motherboards Motherboards (also called mainboards) are actually a carryover from architecture used for years in mainframe computers. Various circuit cards performing various functions all plug into many similar sockets on a common circuit board. Each circuit card performs a unique function in the computer and gets its power from the socket.

The Abit KT-7A supports Advanced Micro Devices (AMD) processors and has the KT-133A chipset. The card slots on the Abit KT-7A, from bottom to top in the image below, shows that ISA has one slot, PCI has six slots and AGP has one slot. A special fan cools the chipset. MSI 694D Pro AR Dual Flip Chip Socket 370 motherboard

A partial view of the TechRam S3ProM motherboard shows slots: From bottom to top, ISA has one slot, PCI has two slots, audio modem riser (AMR) has one slot, and AGP has one slot. Abit KT-7A AMD Processor Motherboard

Microprocessors A microprocessor -- also known as a CPU or central processing unit -- is a complete computation engine that is fabricated on a single chip. The first microprocessor was the Intel 4004, introduced in 1971. The 4004 was not very powerful -- all it could do was add and subtract, and it could only do that 4 bits at a time. But it was amazing that everything was on one chip. Prior to the 4004, engineers built computers either from collections of chips or from discrete components (transistors wired one at a time). The 4004 powered one of the first portable electronic calculators.

Microprocessor Progression: Intel

Information about this table: The date is the year that the processor was first introduced. Many processors are re-introduced at higher clock speeds for many years after the original release date. Transistors is the number of transistors on the chip. You can see that the number of equivalent transistors on a single chip has risen steadily over the years. Microns is the width, in microns, of the smallest wire on the chip. For comparison, a human hair is 100 microns thick. As the feature size on the chip goes down, the number of transistors rises. Clock speed is the maximum rate that the chip can be clocked at. Clock speed will make more sense in the next section.

Information about this table: Data Width is the width of the ALU. An 8-bit ALU can add/subtract/multiply/etc. two 8-bit numbers, while a 32-bit ALU can manipulate 32-bit numbers. An 8-bit ALU would have to execute four instructions to add two 32-bit numbers, while a 32-bit ALU can do it in one instruction. MIPS stands for "millions of instructions per second" and is a rough measure of the performance of a CPU.

Computer Memory memory is technically any form of electronic storage, it is used most often to identify fast, temporary forms of storage. If your computer's CPU had to constantly access the hard drive to retrieve every piece of data it needs, it would operate very slowly. When the information is kept in memory, the CPU can access it much more quickly. Most forms of memory are intended to store data temporarily.

Types of Electronic MemoryRAMROM Flash memory Memory Sticks Video memoryBIOS

RAM memory modules From the top: SIMM, DIMM and SODIMM

Memory Basics The CPU accesses memory according to a distinct hierarchy. Whether it comes from permanent storage (the hard drive) or input (the keyboard), most data goes in random access memory (RAM) first. The CPU then stores pieces of data it will need to access, often in a cache, and maintains certain special instructions in the register.

ROM Read-only memory (ROM), also known as firmware, is an integrated circuit programmed with specific data when it is manufactured. ROM chips are used not only in computers, but in most other electronic items as well.

RAM Random access memory (RAM) is the best known form of computer memory. RAM is considered "random access" because you can access any memory cell directly if you know the row and column that intersect at that cell. The opposite of RAM is serial access memory (SAM). SAM stores data as a series of memory cells that can only be accessed sequentially.

Cable Key IDE devices use a ribbon cable to connect to each other. Ribbon cables have all of the wires laid flat next to each other instead of bunched or wrapped together in a bundle. IDE ribbon cables have either 40 or 80 wires. There is a connector at each end of the cable and another one about two-thirds of the distance from the motherboard connector.

USB Ports Just about any computer that you buy today comes with one or more Universal Serial Bus connectors on the back. These USB connectors let you attach everything from mice to printers to your computer quickly and easily. The operating system supports USB as well, so the installation of the device drivers is quick and easy, too.

Sample List of USB Devices

Printers Scanners MiceJoysticksDigital camerasWebcamsModemsSpeakers Telephones Network connections

The rectangular socket is a typical USB socket on the back of a PC

The USB standard uses "A" and "B" connectors to avoid confusion: "A" connectors head "upstream" toward the computer. "B" connectors head "downstream" and connect to individual devices.

Serial Ports Considered to be one of the most basic external connections to a computer, the serial port has been an integral part of most computers.Serial ports provide a standard connector and protocol to let you attach devices, such as modems, to your computer.

The Serial Connection

Parallel Ports Parallel ports were originally developed by IBM as a way to connect a printer to your PC. When IBM was in the process of designing the PC, the company wanted the computer to work with printers offered by Centronics, a top printer manufacturer at the time. A typical parallel port on the back of your computer

Parallel ports can be used to connect a host of popular computer peripherals: PrintersScannersCD burners External hard drives Iomega Zip removable drivesNetwork adapters

Peripheral Component Interconnect (PCI) PCI cards use 47 pins A typical PCI card

AGP Accelerated Graphics Port AGP and AGP graphics cards are now the standard for processing graphics on computers. Like all hardware, the technology and specifications are constantly improving.

Hard Disks Hard disks were invented in the 1950s. They started as large disks up to 20 inches in diameter holding just a few megabytes. They were originally called "fixed disks").

PC Power Supplies In a personal computer (PC), the power supply is the metal box usually found in a corner of the case. The power supply is visible from the back of many systems because it contains the power-cord receptacle and the cooling fan.

Power Supply Wattage

Computer Keyboards The part of the computer that we come into most contact with is probably the piece that we think about the least. But the keyboard is an amazing piece of technology. An Apple Extended keyboard

Types of Keyboards 101-key Enhanced keyboard 104-key Windows keyboard 82-key Apple standard keyboard 108-key Apple Extended keyboard

Data Interface Most mice in use today use the standard PS/2 type connector. These pins have the following functions 1.Unused 2.+5 volts (to power the chip and LEDs) 3.Unused 4.Clock 5.Ground 6.Data A typical PS/2 connector: Assume that pin 1 is located just to the left of the black alignment pin, and the others are numbered clockwise from there.

BIOS

BIOS One of the most common uses of Flash memory is for the basic input/output system of your computer, commonly known as the BIOS (pronounced "bye-ose"). On virtually every computer available, the BIOS makes sure all the other chips, hard drives, ports and CPU function together. The BIOS is special software that interfaces the major hardware components of your computer with the operating system. It is usually stored on a Flash memory chip on the motherboard, but sometimes the chip is another type of ROM.

What BIOS Does When you turn on your computer, the BIOS does several things. This is its usual sequence: 1.Check the CMOS Setup for custom settings 2.Load the interrupt handlers and device drivers 3.Initialize registers and power management 4.Perform the power-on self-test (POST) 5.Display system settings 6.Determine which devices are bootable 7.Initiate the bootstrap sequence

Configuring BIOSTo enter the CMOS Setup, you must press a certain key or combination of keys during the initial startup sequence. Most systems use "Esc," "Del," "F1," "F2," "Ctrl-Esc" or "Ctrl-Alt-Esc" to enter setup. Once you have entered setup, you will see a set of text screens with a number of options.

Common options include: System Time/Date - Set the system time and date Boot Sequence - The order that BIOS will try to load the operating system Plug and Play - A standard for auto-detecting connected devices; should be set to "Yes" if your computer and operating system both support it CMOS Setup

Preventive Maintenance

Preventive MaintenanceCleaning of Computer, Keyboard and PrinterCleaning of Pointing DeviceTaking care of ComputerTo take care of your CDs

Cleaning of Computer, Keyboard and PrinterTurn off the computer and unplug the power cordIsolate your body to any negative area/s.Use soft cloth moistened with water an gently wipe the exterior of the computer, keyboard and printer.

Cleaning of Pointing DeviceOpen the circular cover underneath the mouseTake out the rubber ball and wipe it with a soft, damp clothPut the ball and close the cover

Taking care of ComputerDo not expose the computer to direct sunlightDo not subject the computer to magnetic fieldsDo not expose the computer to dust and dirtNever place the system on uneven surfaces

To take care of your CDsKeep your disc in its case when not in use to avoid scratches or other damage.When cleaning disc, use a clean, dust free cloth and wipe in a straight line from the center to the edge.Clean your CD drive periodically.

Troubleshooting

TroubleshootingNo DisplayNo PowerBoot-up ProblemKeyboard ProblemMouse ProblemFloppy Disk Drive ProblemPrinting Problem

No Display Check cable connections Try restarting the computer Test the computer with other monitor

No Power Check AC output voltage Check power cable connections Check the computer power supply

Boot-up Problem Check CMOS configuration Remove any disk inserted in the floppy/cd drive

Keyboard ProblemCheck connectionsTest with other keyboardRe-start the system

Mouse ProblemReset connectionReplace with other mouseTry restarting

Floppy/CD Disk Drive ProblemCheck CMOS configurationTry using another set of disks/CDsClean drive with Disk Cleaner

Printing ProblemsCheck printer powerCheck cable connectionsCheck ink cartridgeReplace printer cableCheck the printer driver, may need to be installed

Operating Systems The operating system defines our computing experience. It's the first software we see when we turn on the computer, and the last software we see when the computer is turned off. It's the software that enables all the programs we use.

At the simplest level, an operating system does two things: It manages the hardware and software resources of the computer system. These resources include such things as the processor, memory, disk space, etc. It provides a stable, consistent way for applications to deal with the hardware without having to know all the details of the hardware.

The operating system's tasks, in the most general sense, fall into six categories: Processor management Memory management Device management Storage management Application interface User interface

** Elaborate purpose of transitors to illustrate increase in power/capacity** Most forms of memory are intended to store data temporarily. *COSIDER DELETION*Emphazie: 1) Stripe 2) Key*Primarily: audio, video, lan, modem*Check if presnt**Note POST