Computer Repairing and Maintain Page 1 Hardware :- All physical part of computer is known as computer hardware which can be see or touch . Example :- Keyboard, Mouse, monitor, hard disk, etc. System Case(System Box) :- System Case is the central unit of any computer system inside the system box you can find CPU, mother board, FDD, HDD, FDDC, HDDC, SMPS, daughter board, etc. UNIT 1 Introduction To Computer
Computer Repairing and Maintain Page 2 Structure of PC Hardware PC-Hardware :- A PC – hardware is organized into two types they are :- i) 2 box structure ii) 3 box structure i) 2 box structure :- A Pc with 2 box structure was used in early 1980’s. Here , the output unit CRT monitor is physically assembled within the system box and keyboard as the second box given as two box appearance to a personal computer all necessary hardware of PC housed only in these two boxes. 3 box structure :- i) Flip open :-
Computer Repairing and Maintain Page 3 In flip open type cabinet the Top cover of system box can be lifted up and completely opened. Where as in pull open type system box top cover comes in the front but only after unscrewing the arrangement. New form factor of system box: PC – Hardware Block Diagram
Computer Repairing and Maintain Page 4 Back Panel Connection :- i) AC Power Supply ii) Air windows iii) Keyboard Connector iv) Mouse Connector v) USB connector (Universal Serial Bus Connector) vi) RJ45 Connector ( Register Jack 45 connector) vii) AGP connector ( Accelerated Graphic Port AGP is used for monitor connector. RJ45 is used for wifi connector. Front Panel Connector :- i) Power indicator ii) Reset Button iii) HDD LED iv) FDD LED v) Turbo Button ( It is used to on/off the computer) vi) USB System Bus :- The system bus is also called PC bus. They are :- i) Address Bus ii) Data Bus iii) Control Bus System Bus :-
Computer Repairing and Maintain Page 5 The system bus is also called PC Bus which is available on add on card in front of (Input / Output) slots (62 pins Input/output slot). This system bus comprises the address bus (carried address signal A0 – A15 ) data bus (carried data signal D0 – D7) and control bus (carried signal such as MEMR (Memory Read), MEMW (Memory Write), interrupt etc. Thus, the communication between Peripherals and different hardware section on the motherboard is established via systwm bus. These PC uses PC bus (I/O) bus PC AT 286 ISA or AT bus (Industry Standard Architecture). 386 ------------ESTA (Extended Industry Standard Architecture) 486------------VESA (Video Electronics Standard Association) PCI Local Bus :- At first , Bus had a limitation of 8 to 32 bit path and 33 MHZ maximum speed.To over come these limitation bus specification called PCI (Peripheral Component Interconnect )with the Pentium processor PCI is standard local bus . It support of Pentium processor. It’s advantages are :- I) It’s has more capacity of transferring data. II) It’s processing speed is high.
Computer Repairing and Maintain Page 6 III) It increases the performance of system. AGP (Accelerated Graphics Port ) :- It is a high speed bus for the boards AGP slot on the mother board is usually darker in color and used only for display card . A mother board have only one AGP slot when the AGP first came in the market it’s speed was 1x , now latest P4 system offer 8x AGP slots. AGP make faster communication between the graphics controller and computer. This also help to reduce the traffic on the PCI bus. Function of BIOS :- 1. BIOS interact with operating system. 2. It ensures the basic operability of each component by using the list of all the hardware in in the system. 3. It identifies and configures new hardware like hard drives, Floppy drives .Find a valid operating system and transfer the control of the system to that operating system after the boot function have completed. Motherboard Form Factor :- The form factor determines the layout and shape of a motherboard. It describes how the individual component of motherboard are placed on the motherboard. The different features and size for the motherboard of the company. Some common motherboard form factor are listed below:- I. At form factor II. ATX form factor III. Micro ATX form factor IV. LPX form factor V. Baby AT form factor VI. Mini ATX form factor VII. Flex ATX form factor VIII. NlX form factor 1. At form factor :-
Computer Repairing and Maintain Page 7 It is most widely used form factor. AT was invented in 1984 by IBM its size is 12” long and wide. The at power provides 192 watts. The major problem of this form factor is its width due to. Which some part of board overlaps with the drive bays ( connecting devices ). 2. ATX form factor :- This form factor was created by intel in 1995. It was introduce with many changes in computer case and motherboard design ATX motherboard become popular due to their advantages. It have integrated (input/output) port connector that are mounted on the motherboard and improved power supply connector and design that makes the upgrading of the motherboard easier. 3. Micro ATX form factor :- It is another smaller version of intel’s ATX. The maximum size of the board is 9.6” square. It use a smaller power supply and fewer number of expansion slots. As its size is reduced. 4. Mini ATX form factor :- The mini ATX motherboard is slightly smaller than the ATX motherboard remaining same as ATX. 5. Flex ATX form factor :- Intel introduced the micro ATX motherboard With the reduced size is known as flex ATX form factor. Its size is 9” long and 7.5” wide. It support only socket processor technology and same mounting holes as micro ATX. 6. LPX form factor :- It was introduced in the LPX design normally featured the main (input/output) port mounted on back of motherboard and a riser card in center of the motherboard. It has sound and video cards integrated located at the center. PCB :- Printed Circuit Board. 7. NLX form factor :- Intel introduced NLX design in 1997. The NLX format is smaller, typically 8” wide and 13” wide so well suited for low profile desktop case. All expansive slots, power cables and peripherals connectors are located on the mounted riser card, allowing simple removal of main motherboard which is mounted on the surface of the chassis. S.N Name Figure
Computer Repairing and Maintain Page 8 1. AT Form Factor 2. ATX Form Factor 3. Micro ATX Form Factor
Computer Repairing and Maintain Page 9 4. LPX Form Factor 5. Baby AT Form Factor 6. Mini ATX Form Factor 7. Flex ATX Form Factor
Computer Repairing and Maintain Page 10 8. NLX Form Factor SMPS ( Switch Mode Power Supply) :- A power supply unit housed in system box of PC supplies the necessary DC power to the different part like motherboard FDD, HDD etc. The primary power that is AC 230 V is supplied to the SMPS directly from the wall plug. The SMPS unit is smaller in size, light, weight and more efficient power supply. It will not waste the power but it switch only the required power to the output. This switch supply is basically a voltage controlled switch. Most of SMPS supply unit regulate their output using a method called pulse width modulation. The capacity of the power supply is measured in watts as the load to the power presented each and every unit and peripherals that is plugged into it. The output voltage of SMPS is + _ 12 V. AT power connector :- AT power connector have two 6 power connectors named P8 and P9 which are connected to the motherboard with black wire facing each other. The various form factor of the power supply such as PC XT, AT, baby AT and
Computer Repairing and Maintain Page 11 LPX use a part of 6 wire connector to connect the power supplyto the motherboard. ATX power connector :- ATX power connector is a 20 pins connector which are used by ATX form factor and NLX form factor. Fig:ATX Power Connector Standard peripherals power connector :- It is also known as 4 pin Molex power cable. The 4 pin wire connector are available in large as well as small size connector. Fig :- Standard peripherals power connector Processor :-
Computer Repairing and Maintain Page 12 Microprocessor is the multipurpose, programmable clock driven, register based electronic device that reads binary instruction from a storage device called memory accept binary data is input process data according to those instruction and provide results as output. The major manufactures are inter, Motorola, Cyrix, Advanced Micro Device (ADM). Dual voltage processor requires two different voltage are external and internal. The the external (input/output) voltage is 3.3 v and the internal voltage is usually 2.8 v and 3.2 v. Processor cooling :- The heat produced by the functioning of the system can harm the internal component of the computer system. To prevent the component from being damaged the cooling system are used to reduced the heat. Fig :- Processor Cooling Fans :- The system power supply and the system case contains a fan in it that helps conduit air flow in or out from the system
Computer Repairing and Maintain Page 13 case. This helps in cooling the component located inside the system case and prevents them from being damaged. Fig :- fans Heat sinks :- A heat sinks is an object that absorbs and dissipate heat from another object using thermal a heat sinks absorbs heat from the processor and the air flowing over this heat sink cools the processor. Fig :- Heat Sinks Processor socket :- The socket such as socket 3, socket 8, socket 370, socket 775 and socket 939 support microprocessor with different voltage The processor has interfaced with the system motherboard through a socket. The role of socket is provide electrical connecting between the processor and motherboard. . Socket 3 :- Supports microprocessor that has 327 pins. In this socket, the arrangements of pins are in four rows. This sockets supplies 3.3 v to 5 v to microprocessor. This socket support 80486D series microprocessor along with the AMD586, cyrix 5 and Pentium I. Fig:Socket 3 Socket 8 :- Supports microprocessor that has 387 pins in this socket the pins are arranged in five rows it supplies 3.1 v to 3.8 v to microprocessor. This sockets supports the Pentium pro microprocessor and it rectangular in shape. Fig :- Socket 8 Socket 370 :- Support the microprocessor that has 370 pins. The socket 370 has the voltage range of 1.05 v to 2.1 v. It supports the intel Celeron and Pentium III microprocessor. Socket 775 :- It contains 775 pins. This sockets all the latest processor such as Intel p4 extreme edition processor Intel Pentium with hyper. Threading technology.
Computer Repairing and Maintain Page 14 Socket 939 :- Supports bits computing and 939 pins. Its supports AMD Athlon 64 Fx and AMD petron processor it has an operating voltage of 0.8 to 1.55 volts. Computer memory System Memory size capacity S.NO. Name Size Capacity 1. CD-ROM 4.75” 650 MB to 1 GB 2. DVD 4.75” 4 GB to 17 GB 3. Blue-Ray 4.75” 25 GB 4. Floppy disk 3.5” 1.44 MB
Computer Repairing and Maintain Page 15 5. Hard disk 3.75” 10 GB to several GB CD-ROM :- CD-ROM stand for Compact Disk-Read Only Memory. It is a type of opticaldisk capable of storing data upto 700 MB. It contains pre- recorded data that can be read only (i.e can not be modified). A laser beam is used to write and read data from CD-ROM. Fig :-CD-ROM CD-R/W :- CD-R/W stands for Compact Disk-Read/Write. It is a new type of CD-Disk that maples the user to read and write data many times with CD-R/W drive and disk. Fig :-CD-RW DVD :- DVD is stand for Digital Versatile Disk. DVD ROM is high density medium capable of storing a full length movie on a single disk. It use special data compression technology and extremely small tacks for storing data. Fig :- DVD Video Cards :- A computer and monitor without any video display card attached to it. It is no use for you . A display adapter or video card is must necessary for transferring data from the CPU to the monitor. Fig :- Video Card Video Mode :- It refers pixel (picture element) to the characteristics of a computer display in particular the maximum number of colors maximum image resolution
Computer Repairing and Maintain Page 16 (in pixels horizontally by pixels vertically). There are several displayed modes that can be found in PC today. Types Resolution in pixel Supporting colors CGA(Color Graphic Adapter) 320*200 4 colors EGA(Enhanced Graphic Adapter) 640*350 16,64 colors VGA(Video Graphic Array) 320*200 256 colors SVGA(Super Video Graphic Array) 800*600 16 colors SVGA(Super Video Graphic Array) 1024*764 256 colors XGA(Extended Graphic Adapter) 1024*768 256 colors Monitor :- A computer monitor is an output device that display the computers user interface and information requested by the user. Types of monitor :- There are different types of monitors available in the market. They are classified on the basics +of the technology such as CRT and LCD that used to display both image and text. I. CRT ( Cathode Ray Tube ) II. LCD ( Liquid Crystal Display ) 1. CRT :- CRT monitor was invented by karl Ferdinand Braun. This monitor is heavy, thick and has picture tube. It is a economic monitor , that is used in most of the system in the CRT monitor, a beam of electrons, strikes of electrons with phosphorus produce light. CRT monitor are generally available in flat and curved shape. Fig :- CRT Monitor 2. LCD :- It is one of the most widely used flat panel monitor. The LCD is popular as display device as compare to CRT because of its power consumption
Computer Repairing and Maintain Page 17 thinness and high resolution. But to this, it is widely used in digital television, laptops, computers and digital cameras. LCD take up less desk space and they are lighter as compare to the CRT monitor. Now a days LCD monitor use thin film transistor ( TFT ) technology to display image on monitor screen. Fig :- LCD monitor Size of monitor :- The size of monitor refers to the length of the monitor in inches. Monitor are generally available in different sizes ranging from 14 inches to 22 inches. The size of monitor is measured diagonally. Refresh Rate :- The monitor of times in one second that the image on a monitor is redrawn is called its refresh rate it is measure in (Hz) Hertz. Resolution :- The sharpness of the image on a display depends on the resolution and the size of monitor. Color depth :- The number of distinct colors that can be represented by a piece of hardware or software it is also refered to as bit per pixel (b). Keyboard :- It is a input device used to enter data in a computer. It contains various keys such as alphanumeric keys, enter key, etc. Types of keyboard :- The following are different types of keyboards by which a user can perform various tasks such as typing a document, use key strike, shortcuts, access memory so on. 101-key enhanced keyboard 104-key windows keyboard Ergonomic keyboard Multimedia keyboard Cordless keyboard (wireless keyboard). Keyboard connector :- The keyboard connector is device that is used to connect keyboard and computer. 5-pin din connector 6-pin Ps/2 connector 4-pin USB connector USB = Universal Serial Bus “ Grouping of key on keyboard” 1. Numeric key :- 0 to 9 2. Cursor movement keys :- 3. Function keys :- F1 to F12
Computer Repairing and Maintain Page 18 4. Special purpose keys :- Caps lock, Num lock, Scroll lock, Alt, Enter, Tab, Esc, Ctrl, Space, Home, End, Insert, Page Down, Delete, Page up etc. 5. Alphabet keys :- A to Z Fig :- Key board Numeric keys :- Number are provided on the top of Alphabet area and on the right corner of the keyboard. The number keypad on the extreme right of the keyboard and can be used to enter number when the “num lock” indicator is on ( 0 to 9). Format of Disk :- A new hard disk can be used for various operating system provided they are appropriately formatted formatting is the process of preparing the blank hard disk for particular operating system. Formatting a hard disk puts special magnetic marks of track and sectors on the hard disk surface, these are magnetic information written on the disk media one cannot see it on the disk surface. Partition :- Partitioning is a new concept introduced by IBM when they launched the 10 MB hard disk was considered very big storage area and they decided to use it. For two different operating systems, DOS and ENIX by driving the drive into two logical parts or volumes to install two operating systems that is DOS and XENIX. The MAX number partition by DOS is 24. The first partition name is C and last partition is given Z so, form C to Z only 24 letter are used for partition name. Where as A and B is reserved for floppy drive. Disk partition(Active Partition) :- Basic disk can be divided into primary and extended partitions. They can be divided into a maximum of four partition you can either have four partition or these primary partitions and one extended partitions. Extended partition :-
Computer Repairing and Maintain Page 19 Only one extended partition can be created on a hard disk. The extended partition is created from free space on the disk. Extended partition are divided into segments called logical drive. Interface ( Connector ) :- ATA:- i. It stands for Advanced Technology Attachment. ii. It gives 40 pin connector. iii. Length of cable is 18 inch. iv. Used to connect motherboard to hard disk, Optical drive(CD-ROM). v. Data Transfer rate 100 MBPs to MBPs.Fig :- ATA SATA :- i. It stands for Serial Advanced Technology Attachment. ii. It uses two pair of wires. iii. It uses 12 inch to 1 meter. iv. It is used to connect motherboard to hard disk/Optical drive. v. Data Transfer rate is 150 to 300 MBPs.Fig :- SATA PATA :- i. It stands for parallel Advanced Technology Attachament. ii. It gives 40 pin connector. iii. Length of cable is 18 inch. iv. Used to connect motherboard to hard disk, Optical drive(CD-ROM). v. Data Transfer rate 100 MBPs to MBPs. Fig :- PATA Construction and operation of Hard Disk :-
Computer Repairing and Maintain Page 20 Fig :- Construction And operation of hard disk The Hard disk platter are accessed for read and write operation using the Read/Write heads mounted on the top and bottom . Surface of each platter obviously the read/write head do not just float in space. They must be held in an exact position relative to the surface they are reading and further more, they must are movedfrom track to track to allow access to the entire surface of the disk. The heads are mounted onto a structure that facilities this process. Disk Geometry :- The hard disk stores data as magnetic information on its surface if the data is stored continuously one next to another then at the time of retrival one will have to scan the entire hard disk to find the required data to arrange the data properly on the disk It divided into different section called head side, track, sectors etc. The written data on disk’s track and sector are saved in an index like place called directory and FAT (File Allocation Table). When the data is required the computer looks at the entire directory and FAT.
Computer Repairing and Maintain Page 21 Fig :- Disk geometry Tracks :- Each side of the hard disk drives platter surface is divided into concentric circle called track. These track are not visible on the disk surface instead these are magnetic information written during formatting of the hard disk. It stored upto 5000 Byte. Sector :- Different capacity of hard disk drive divided into the track and track divided into number of sectors. Where 512 Bytes of data stored per sector. Cylinder :- A track usually refers to one parts of the cylinder i.e track is one side of the platter whereas a cylinder is combination of all the tracks. Preventive Maintenance :- It is systematic inspection, detection, correction and maintenance of incipient failures. Preventive maintenance (PM) has goal to improving the life of system’s device and component by cleaning, repairs and replacement. Cooling and Ventilation :- A cool system runs more reliable and durable than one that runs at hot environment. Computer needs air-conditioning system to maintain the temperature between 210 to 240 Celsius. Computer virus :- It is a type of computer program which is written by the programmer with the intent of destroying damaging the data & program residing in the computer system. For Example :- I Love You, Acid rain etc To earn Money Take file of other It is a destructive program Types of virus UNIT 2 System Care Guide
Computer Repairing and Maintain Page 22 Stealth” File” whale virus Micro” Anti-viral software :- It is designed to detect and remove viruses from computer system to ensure a virus free environment. Example :- Quick heal, K7, Nordon, Panda etc. Virus Detection (Symptoms of virus) :- I. Program take a long time to load. II. The floppy or hard disk is suddenly accessed without a logical reason. III. Increased use of disk space and growth in file size. IV. Renaming all files with different names. V. Corrupting the system’s data. Virus protection ( safe computing ):- The spread of computer virus infection can be stopped through the practice of safe computing some of the steps are given below :- i. Do not install pirated software. ii. Do not interchange the internal disks of computer. iii. Do not use the free distributed software. iv. Scan the disk frequently and take out the virus infected files. v. Use a good anti-virus program to scan disks. Difference between virus and anti-virus Virus Antivirus 1. It is a destructive program written by the programmer with the intent of damaging the files residing in the computer system. 1. It is a type of software designed to detect and remove virus from the computer. 2. It decrease the performance of system. 2. It maintain the performance of system. 3. Due to virus hard disk and floppy disk suddenly accessed without any logical reason. 3. Due to antivirus only the disk and floppy disk accessed that we want. 4. It corrupt the system data. 4. It doesn’t allow to corrupt the system data. 5. It shows growth in file size and increase use of disk space. 5. It shows the actual files size and doesn’t use disk space unnecessary.
Computer Repairing and Maintain Page 23 Virus infection mechanism and prevention;- A virus usually passed through infected files of disk and Internet . some viruses only transfer if you boot your computer with an infected disk other can infect your system when you copy a file from an infected disk or download of file from the Internet or access data or program on network If you install genuine software and rarely exchange disk with anyone else it may reduce the risk of virus infection in the computer system . Background on viruses:- A virus can spread from one computer to another (in executable code) when its host is taken to the target computer for instance because a user sent it over a network or internet or carried it on a removable medium such as floppy disk , CD , DVD , USB drive . Virus can increase their chance of spreading to other computer by infecting files in network file system that is accessed by another computer . some viruses and other malware have symptoms noticeable to the computer user. Backup:- Backups are a way of securing your information thry are another copy of all your important computer data or files kept in another location. These files are kept on hard disk ,CD, and tapes. Our programs are lost by incipient failures ,power fluctuation ,viruses Why we use backup in computer system ? We use backup in computer system to save our information residing in the computer system which may be lost by incipient failures, power fluctuation, spread of viruses in computer. Backup method, devices and media :- There are many different methods that you can use to backup the data on your hard disk. The primary difference between these medium that is used to store the backup, different media have different characteristics such as capacity, speed and university etc. You may choose any one of methods, devices and media as per requirement and budget. The quickest way to backup files is to plug on external hard disk or thumb drive into your computer and copy the files to it. Boot disk :- The disk where all bootable files are stored (startup) is known as bootable or boot disk. 6. Example :- JC wheel, Boot sector virus, etc. 6. Example :- K7, Quick heal, Norton, etc
Computer Repairing and Maintain Page 24 What to Back up ? All important software those are very useful in future that must takes backup to save from potential disasters and damage. How to Backup ? The quickest way to backup files is to plug an external hard drive or thumb drive into your computer and copy the files to it or use another backup software you can also use CDs, DVDs, tape drive etc. Backup scheduling and media rotation system :- In order to provides maximum safety for your, it is important to plan out a backup schedule that will allow you the most flexibility disasters that means in almost every case, the use of multiple backup media and a backup schedule that help when each set of media should be use. The amount of media needed that depends on how safe you wanted to be, and what rotation period you are looking to maintain for your data. This setting that provide different level of protection by using single tape, a group of zip drives or whatever as per requirement and budget. Advantages of Backup It provides more safety to our data than normal backup. It also provides more flexibility and reliability in recovering from potential disaster. Disadvantages of backup It is expensive. It is difficult to manage. Expert manpower can use this backup. It required more storage device.
Computer Repairing and Maintain Page 25 General troubleshooting techniques:-There are many basic troubleshooting techniques you can use to fix issues like this . In this lesson, we will show you simple things to try when troubleshooting as well as how to solve common problems. You may encounter (particulars types of experiences). Step to take first when troubleshooting:- There are many different tricks and techniques that we outline (general explanation or description) in the troubleshooting guide but the oncethe few that we always recommended to tried first before proceeding into a full troubleshooting effort . The reason is simple they can often solve the problem you are having before send time. The use of diagnostic tool can save your great deal of time while in our experience. These tools do not usually identify what the cause of a system problem is , they often provide hints or at least valuable information about what is in the system and how it is working . Diagnostic, troubleshooting and repair tools:-Troubleshootinga problem with a pc can be very difficult and frustrating . Fortunately there are places to turn for assistance and tools that can make the job much easier to identify specific problems within the pc or just give you more information about the system . UNIT 3 GENERAL TROUBLESHOOTING AND TECHNIQUES
Computer Repairing and Maintain Page 26 Diagnostic software tools:- Microsoft scan disk Post (power on self-test) .mem, .exe (this simple utility, built into DOS, WINDOWS 95) diagnostic hardware tools:- Screw driver Electrical tape Soldering irons Wire ships etc. Pliers. Multimeter. S.N Name Pictures 1. Screw Driver 2. Electrical Tape 3. Soldering Irons
Computer Repairing and Maintain Page 27 4. Wire Ships 5. Pliers 6. Multimeter Trouble shooting boot problem:- This section of the troubleshooting expert is dedicated to troubleshooting problems getting the PC to boot up (startup) to the point where the operating system is loaded. Basically, if you get to the point where the PC display “starting MS-DOS” or windows or similar the hardware is booting or not. To solve this problem:- 1. Go to system BIOS setting and shoe bootable file’s are loaded. 2. Boot from floppy, pen, hard disk. 3. Check power cable of storage media. 4. check data cable.
Computer Repairing and Maintain Page 28 Troubleshooting boot time error message:- The BIOS performs a (post) when it starts up the system to check out the PC and make sure that everything is working properly. Assuming that the BIOS is able to boot the system far enough to gain access to the video sub system. It will display information about the PC as it boot it will also display error message to the user. (message or beep sound) Some of boot time error message are:- Disk drive failure Insert bootable media Insert bootable disk Long or short beep code depends on manufacture company. Problem i. computer does not start. ii. bootable file is missing. iii. operating system take long time to boot system. iv. long beep sound at same interval of time. v. Data cable failure. Solution i. Check the power supply. ii. Insert bootable media. iii. Go to BIOS to show bootable media. iv. Check RAM slot and clean. v. Check the data cable Solution for data cable i. Check the power supply. ii. Check data cable. iii. Device driver install. iv. Download and install. Troubleshooting system slow down:- There are number of different situations that can be responsible for the system performance changing. Some of the steps to solve this problem. Scan disk Try to defragmenting the disk. Scan with antiviral software. Clean icon or folder from screen. Delete file or folder which is not useful.
Computer Repairing and Maintain Page 29 CD-ROM not recognized /Hard Disk/Scanner/Printer/Keyboard/Mouse: 1. Ensure that the power is connected properly 2. Ensure that the data cable is connected properly. 3. Check the status of the device manager( is working properly) 4. Make sure that the driver’s installed properly. Image Quality problem: 1. Choose resolution setting 2. Re-install video card driver. 3. Choose new Quality picture tube. 4. Choose Good quality picture tube. 5. Check the power supply of monitor. Failure or Improper Operation of Monitor: 1. Verified that the monitor is connected to the power source. 2. Check that the monitor is connected yo the pc’s or video card and ensure that the power is proper. 3. Check the brightness and contrast controls have not been turned all the way up which result in dark screen. 4. Reboot the PC listen for beep sounds and watch for error messages (may be problem in video card or other). 5. Replace the monitor with a new monitor if the display appears then it means that the previous monitor was faulty. Performance or video mode issues: This section covers performance issues related to the video card as well as problem changing the video mode(resolution or color depth) SOLVE THE PROBLEM: 1. Use new standard cable. 2. Try to use UP-TO_DATE driver that can be found on the company’s website. 3. Select required resolution depth and color by right click on desktop . 4. Choose screen resolution. 5. Select resolution. 6. Click on advance setting. 7. Click on list all mode. 8. Choose appropriate bit of color. 9. Click on “OK” apply.
Computer Repairing and Maintain Page 30 Image quality problem(video controller issue): 1. Use a new standard cable and DVI (Digital Video Interface)technology that enhance the quality of video graphics cards. 2. Make sure that you are using the correct driver for your video cards. 3. Try to use its own driver which is provided by its company. 4. Otherwise try to UP-TO-DATE drivers that can be found on the company’s website. Memory Not Recognized: The system memory not be recognized by the system ,either by BIOS or operating system. TO SOLVE THE PROBLEM: 1. Change the slot of memory. 2. Clean the slot of memory. 3. Remove the carbon fronm RAM and slot. 4. Replace the memory. OUT OF MEMORY PROBLEMS: The problems where the system is saying it is out of memory where no.addiional memory can be allocated for use by progams and operating system. TO SOLVE THE PROBLEM: 1. Upgrade the memory . 2. Install modern operating System which provide virtual memory. 3. Delete unwanted files or folder from Harddisk . Video card failure or improper operation: 1. To be sure of the exact video chip set and version level of card is compatible. 2. Check that the display has power and connected properly. 3. Boot the systemat save mode. 4. Re-install driver of cards. 5. Check monitors fuse. 6. Remove video card and again plug into the slot. Assembly of physical device issues: This procedure describes some overall system checks that I recommend you perform after completing significant assembly procedures such as a new PC Build or a motherboard upgrade.
Computer Repairing and Maintain Page 31 1. Re-check some of the more important aspects of assembly,to reduce the unsuccessful start of the system . 2. Power inspection. 3. Make sure that the CPU fan and addition case fans have their power connected are attached. 4. Cable inspection of Hard disk,CD-ROM,floppy,mouse,keyboard. 5. MOTHERBOARD INSPECTION: a) Re-check motherboard jump setting. b) Make sure the memory is inserted into the slot. c) Make sure the processor is inserted properly. d) Ensure that the heat sink is secured properly. 6.PHYSICAL INTERFACE INSPECTION: a) Ensure that all the drive are properly physically connected in their bays. b) Make sure there are no loose wires. c) Make sure that nothing from outside fall into the case by accident. LED,CASE,BUTTONS,KEYLOCK: This section discuss problms related to the LEDs and buttons on front of the case. These connection are depends on manufacture and printed on PCB(Peripheral Component Interconnect). Pin No. 1 LED+ 2 No connection 3 LED4 Key lock 5 Ground keylock