Free download computer hardware troubleshooting book

These high-end computers cost more than the basic desktop computer. Another expensive, powerful desktop computer is the workstation, which is geared for work that requires intense calculations and graphics capabilities.

An architect uses a workstation to design buildings and homes. A graphic artist uses a workstation to create computer-animated special effects for full-length motion pictures and video games. Similarly, a mobile device is a computing device small enough to hold in your hand.

The most popular type of mobile computer is the Notebook computer. The following sections discuss the notebook computer and widely used mobile devices. Notebook Computers Laptop A notebook computer, also called a laptop computer, is a portable, personal computer often designed to fit on your lap. Notebook computers are thin and lightweight, yet they can be as powerful as the average desktop computer. A netbook, which is a type of notebook computer, is smaller, lighter than and often not as powerful as a traditional notebook computer.

Most netbooks cost less than traditional notebook computers, usually only a few hundred dollars. An ultra-thin is another type of notebook computer that is lightweight and usually less than one-inch thick.

Some notebook computers have touch screens, allowing you to interact with the device by touching the screen, usually with the tip of a finger. On a typical notebook computer, the keyboard is on top of the system unit, and the monitor attaches to the system unit with hinges. These computers weigh on average from 2. Most notebook computers can operate on batteries or a power supply or both.

A digital pen looks like a small ink pen but uses pressure instead of ink. Users write or draw on a Tablet PC by pressing a finger or digital pen on the screen, and issue instructions by tapping on the screen. One design of Tablet PC, called a convertible tablet, has an attached keyboard. Another design, which does not include a keyboard, is called a slate tablet and provides other means for typing. Some Tablet PCs also support voice input so that users can speak into the computer.

Tablet PCs are useful especially for taking notes in lectures, at meetings, conferences, and other forums where the standard notebook computer is not practical. Instead, these devices store programs and data permanently on special memory inside the system unit or on small storage media such as memory cards. You often can connect a mobile device to a personal computer to exchange information between the computer and the mobile device. Some mobile devices are Internet-enabled, meaning they can connect to the Internet wirelessly.

With an Internet-enabled device, users can chat, send e- mail and instant messages, and access the Web. Because of their reduced size, the screens on mobile devices are small, but usually are in colour. Popular types of mobile devices are smartphones and PDAs, e-book readers, handheld computers, portable media players, and digital cameras. Smart Phones and PDAs Offering the convenience of one-handed operation, a smart phone is an Internet enabled phone that usually also provides personal information management functions such as a calendar, an appointment book, an address book, a calculator, and a notepad.

In addition to basic phone capabilities, a smart phone allows you to send and receive e-mail messages and access the Web usually for an additional fee. Some smart phones communicate wirelessly with other devices or computers. Many also function as a portable media player and include built-in digital cameras so that you can share photos or videos with others as soon as you capture the image. Many smart phones also offer a variety of application software such as word processing, spreadsheet, and games, and the capability of conducting live video conferences.

Others have a built-in mini keyboard on the front of the phone or a keyboard that slides in and out from behind the phone. Some have touch screens, where you press objects on the screen to make selections and enter text through an on-screen keyboard. Others include a stylus, which is similar to a digital pen but smaller and has less functionality. Types of messages users send with smart phones include text messages, instant messages, picture messages, and video messages. A phone that can send picture messages often is called a camera phone.

A phone that can send video messages often is called a video phone. A PDA personal digital assistant , which often looks like a smart phone, provides personal information management functions such as a calendar, an appointment book, an address book, a calculator, and a notepad.

A PDA differs from a smart phone in that it usually does not provide phone capabilities and may not be Internet-enabled, support voice input, have a built-in camera, or function as a portable media player. As smart phones and PDAs continue a trend of convergence, it is becoming increasingly difficult to differentiate between the two devices.

This has led some manufacturers to refer to PDAs and smart phones simply as handhelds. E-Book Readers An e-book reader short for electronic book reader , or e-reader, is a handheld device that is used primarily for reading e-books.

In addition to books, users typically can purchase and read other forms of digital media such as newspapers and magazines. Most e-book readers have a touch screen and are Internet-enabled. These devices usually are smaller than tablet computers but larger than smart phones. Many handheld computers communicate wirelessly with other devices or computers and also include a digital pen or stylus for input.

Some handheld computers have miniature or specialized keyboards. Many handheld computers are industry-specific and serve the needs of mobile employees, such as meter readers and parcel delivery people, whose jobs require them to move from place to place.

Game Consoles A game console is a mobile computing device designed for single-player or multi-player video games. Weighing on average between two and nine pounds, the compact size of game consoles makes them easy to use at home, in the car, in a hotel, or any location that has an electrical outlet. A handheld game console is small enough to fit in one hand, making it more portable than the standard game console. With the handheld game console, the controls screen, and speakers are built into the device.

Because of their reduced size, the screens are small — three to four inches. Some models use cartridges to store games; others use a memory card or a miniature optical disc. Many handheld game consoles can communicate wirelessly with other similar consoles for multiplayer gaming. Servers can support from two to several thousand connected computers at the same time. In many cases, one server accesses data, information, and programs on another server.

In other cases, people use personal computers or terminals to access data, information, and programs on a server. A terminal is a device with a monitor, keyboard, and memory. Mainframes store tremendous amounts of data, instructions, and information. Most major corporations use mainframes for business activities. With mainframes, enterprises are able to bill millions of customers, prepare payroll for thousands of employees, and manage thousands of items in inventory.

One study reported that mainframes process more than 83 percent of transactions around the world. Mainframes also can act as servers in a network environment.

Servers and other mainframes can access data and information from a mainframe. People also can access programs on the mainframe using terminals or personal computers. The fastest supercomputers are capable of processing more than one quadrillion instructions in a single second.

With weights that exceed tons, these computers can store more than 20, times the data and information of an average desktop computer. Applications requiring complex, sophisticated mathematical calculations use supercomputers.

Large-scale simulations and applications in medicine, aerospace, automotive design, online banking, weather forecasting, nuclear energy research, and petroleum exploration use a supercomputer. Embedded computers are everywhere — at home, in your car, and at work. The following list identifies a variety of everyday products that contain embedded computers. Because embedded computers are components in larger products, they usually are small and have limited hardware.

These computers perform various functions, depending on the requirements of the product in which they reside. Embedded computers in printers, for example, monitor the amount of paper in the tray; check the ink or toner level, signal if a paper jam has occurred, and so on.

Any part that we can see or touch is the hard ware. Display Unit, printer etc. So, what else is required? It requires a set of instructions that tells the computer what is to be done with the input data.

In computer terminology, this set of instructions is called a program and one or more programs are termed as software. Software used for computers may be of different types. The computer understands only machine language i. The software which does this translation is known as the system software.

Examples of system software are compilers and interpreters. Some are linked by expansion cards in expansion slots on the motherboard or connected directly on the ports via a cable attached on them. It has additional keys to handle special functions required by a computer.

Alphanumeric keys Comprises of alphabets A-Z , numbers and other characters. Special keys They perform specific functions. The Shift key when pressed with another key; alters the meaning of any alphanumeric key for e.

Ctrl, Alt and Del pressed together restarts the system. The Esc key is generally used to return to the previous menu or quit a program. The Cursor is a symbol displayed on the screen at the position where text or graphics will be inserted or deleted. The Cursor movement keys move the cursor on the screen. The Num-Lock is used to activate the numeric keys on the Numeric keypad. The Print Screen is used to print whatever is displayed on the screen.

Enter or Return is used to communicate the end of an instruction or data being keyed in through the keyboard. Caps lock is used for keying upper case alphabets. Backspace is used to erase the character to the left of the cursor position. The Function keys are used to perform a set of operations using a single keystroke. The function keys can be defined as special purpose keys. In most of the software, pressing the F1 key will take you to the help feature.

Other than these keys, 3 status indicators are present on the keyboard. There are two type of keyboard. Standard keyboard and Enhanced keyboard. A mouse may have one, two or three buttons. The function each button depends on the program.

Clicking the mouse results in selecting an option. Positioning a cursor with the mouse is easier for non-typists than pressing various key combinations. With an appropriate software, a mouse can also be used to draw pictures. The Computer mouse is of three types and two classifications. SCANNER There are a number of situations when some information picture or text is available on paper and is needed on the computer disk for further manipulation. A scanner is used for this purpose.

A scanner scans an image and transforms it into graphics. These can be edited, manipulated and combined, and then printed. Scanners are used to reproduce photographs on the computer screen. These can be employed in training programs and in desktop publishing.

Types of scanner a Flat-bed scanner or desktop scanner b Optic scanner, looks like a camera c Hand held scanner PRINTER In order to get a copy of the output for later reference, you would require a printer. Printers are capable of printing at a very high speed. Two commonly used printers are the dot-matrix printer and the laser printer. Printers are classified on the basis of a number of parameters like, the mechanism used for printing, speed of printing, quality of output, direction of printing, and the kind of interface they have with the computer.

Printers can be broadly classified as impact and non-impact printers. Let us understand this in detail. Impact Printers Impact printers work like typewriters. The characters are printed by striking the paper i. Impact printers can again be classified as Character printers and Line printers.

Character Printers Character printers print one character at a time. Examples of character printers are. In a DMP, tiny hammers or pins strike the ribbon to produce the desired characters.

The print head consists of 9x7 arrays of pins. Characters to be printed are sent one at a time to the printer. The characters printed are a series of dots. Dot- matrix printers are inexpensive but noisy. They can print both text and graphics. They can print in any language without additional hardware change.

They can also be made to print in colour by changing ribbons. These printers are used everywhere to produce internal reports and memos needed by organizations. Daisy Wheel Printer In a daisy wheel printer, each petal has a character embossed on it. A motor spins the wheel along with it. When the desired character spins to the correct position, a print hammer strikes it to produce a character.

Line printers Line printers print one line at a time. Hence, line printers are generally faster than character printers. Printing speed varies from lines to lines per minute. Some of the line printers are drum printers and chain printers. These can continuously print for a few hours.

Drum printers A drum printer consists of a cylindrical drum. The characters to be printed are embossed on it. A set of print hammers one for each character in a line, are mounted in front of the drum. A character is printed by striking the appropriate hammer against the embossed character on the surface.

The drum completes one revolution to print one line. The movement of the drum and the striking of the hammer must synchronize. Otherwise, the printing will not be uniform. As printer drums are costly they cannot be changed often. Chain Printer A chain printer has a steel band on which the characters are embossed. The band is rotated at a high speed. As the band rotates, a hammer is activated when the desired character comes in front of it.

For every character there will be a hammer. Here also, the hammer movement and the chain movement must be synchronized. The main advantage of the chain printer is that its chain can be easily changed. Thus, different fonts and scripts can be used with the same printer. Some examples of the non-impact are laser printer, thermal printer, and inkjet printer. Laser Printer Laser printers print one page at a time. Laser printers use a light beam to form images on the paper using a toner ink as the medium.

Laser printers are quiet workers. They produce very high quality output both text and graphics. They are typically used publishing. Other Non-impact printers The other types of non-impact printers are thermal printers which use heat to print characters on paper and inkjet printers which use jets of ink to print characters on paper. These printers are not in use as much as the laser printers. It can be used to create presentation-charts, graphics, tables and high quality technical drawings.

There are two types of plotters: Drum and Flat Bed plotter. Drum Plotter The paper is placed over the drum that rotates back and forth. A carriage holding one or more pens is mounted horizontally across the drum. The carriage with the pens moves horizontally over the paper. Each pen could be filled with different colours. This plotter has the ability to produce colour pictures. Flat Bed Plotter In flat bed plotter, the paper does not move.

The carriage holding the pens should provide all motions. Inkjet plotters can also produce large drawings with different colours. The system unit consists of primary storage, arithmetic-logic unit, and the control unit. The CPU interprets instructions to the computer, performs the logical and arithmetic processing operations, and causes the input and output operations to occur. It acts like the central nervous system for all the components though; it does not process any data. These separate areas are not fixed.

The size of each area varies from application to application. ON state is represented by 1 and OFF state is represented by 0. A collection of 8 bits is known as a byte. One Kilobyte represents bytes and one Megabyte represents Kilobytes. Ram Random Access Memory RAM is the area that is used for holding the programs and their data while the computer is working with them.

RAM means the memory can be read from and written to randomly. These sets of programs perform the most basic control and supervisory operations for the computer. But the storage devices are not as fast as the CPU. Most of the time the CPU has to slow down because of these devices. A small section of the high speed RAM is used to keep frequently needed information.

So, one need some storage device to store data and other information. It should be cheap and should not lose the content when power is switched off. This storage is called as the secondary storage. All secondary storage devices act both as input and output devices. Magnetic storage media fulfils these requirements and most common storage devices are disks and tapes.

Floppy Disk It is the most common storage media and it helps transferring the data from one computer to another. Data is stored in these sectors. Each piece of data that is stored, has a track number, a sector number and side number as an address. So data can be accessed randomly from anywhere on the disk.

Hence, it is also called as Random Access storage. The most significant difference between a floppy disk and a hard disk is that the hard-disk is completely sealed and is protected from dust and airborne particles. The name hard disk comes from the rigid platter that is inside the drive. This is, often called by different names like fixed disk or Winchester disk. The hard disk comes in different shapes.

Most hard disks nowadays store something close to MB. Magnetic Tapes Apart from using disks for external storage purposes, magnetic tapes are also used for storing large amount data. The magnetic tape could be a large reel or a small cassette. The tape is essentially a plastic ribbon coated with some material that can be magnetized. The data is recorded on these magnetic spots.

The data on the tape can however be read or written sequentially only. Hence, it is called as sequential access storage. The computer bus consists of two parts, the address bus and a data bus. The data bus transfers actual data, whereas the address bus transfers information about where the data should go. VDUs can work in two different modes viz. Text mode and graphic mode. In text mode, the screen is divided into a matrix of rows and columns; each cell of the matrix is used for one character.

A typical screen has 80 character positions per line and 25 lines across the screen. In graphic mode, the screen is treated as an array of tiny dots called pixels. The characters and pictures that appear on the screen are shown by making a drawing of these pixels. The number of dots on the screen is called as resolution.

A short summary of this paper. Examples of Hardware are following: Input devices: keyboard, mouse etc. Output divices: printer, monitor, speaker etc. The computer case Power Supply. It supplies DC overhea ng of the various electronic of the computer v o l t a g e s f o r i n t e r n a l c o m p u t e r components components and has a fan to keep the computer cool. Hard Disk, Flash Disk etc. Port: Is a connector on the motherboard or on a separate adapter that allows a device to connect to a computer; these may include keyboard, mouse, serial, parallel, network, sound, or video ports.

D-Shell Connector Serial Port. TRS p, ring and sleeve ports Also known as ports for mini-jacks or audio jacks. D-Shell Connector. Game Port. Serial Port. A Program is a sequence of instruc ons wri]en to solve a par cular problem. Opera ng System, Compilers, Interpreter, Assemblers etc. Allow a computer to perform tasks that are not part of the opera ng system, but are s ll prac cal and useful. Both of them must work together to make a computer produce a useful output.

Software cannot be utilized without supporting hardware. Hardware without set of programs to operate upon cannot be utilized and is useless. To get a particular job done on the computer, relevant software should be loaded into the hardware. A device driver is a program that controls a par cular type of device that is a]ached to your computer.

When you buy an opera ng system, many device drivers are built into the product. Hardware is a one-time expense. Different software applications can be loaded on a hardware to run different jobs. A software acts as an interface between the user and the hardware. If Hardware is the 'heart' of a computer system, then Software is its 'soul'.

Both are complimentary to each other. Or the screen blank? These faults are probably also due to hardware problems. This is a code that can be used to dis nguish some hardware problems.

These can be due to hardware or soTware problems. Take careful note of all informa on given in the error code. These error codes are probably due to soTware problems. If so, these are likely culprits. This could be a cause of soTware problems. The Device Manager will list all of the hardware devices installed on a PC. Any device with a problem will have a warning symbol next to it, and double clicking on that device would give d e t a i l s a n d s u g g e s t e d remedies for the problem.

Some possible. This op on will check the applica ons may fail outright if the Hard disk for errors. Some mes this is desirable, some mes not. Either way, this prac ce may slow your computer down to various degrees, and with the program running all the me, may slow down the performance of your computer. Note: Please use cau on when uninstalling socware. These cyber-threats can cause huge dilemmas to your computer. Note: Modern computers have safeguards that shut down the system if a component is overhea ng.

The performance will be slow. This problem is most likely if the computer is rather old and has had a newer and more memory demanding opera ng system installed. It will reduce the performance of the computer. Check to be sure if the computer is plugged in to an AC outlet properly.

It ensures that all of the system's hardware is working properly before trying to load the opera ng system. If the computer does not pass POST, it will not boot. Tip: Make sure the computer turns on. If nothing happens no lights, no sound, no fans, etc.