Personal Computer Components
If two drives are attached to one controller in a computer, one drive should be set as Master and the other as Slave.
If you are unable to open the CD-ROM drive tray by pushing the Eject button on the front panel, open it by inserting a pin into the eject hole on the CD-ROM drive.
Secure Digital (SD) card is a non-volatile memory card format used in portable devices such as mobile phones, digital cameras, and handheld computers.
CD-ROM, SD card, USB Pen drive, floppy disk, etc., are removable storage media.
The serial port comes with two types of connectors, 9-pin and 25-pin. It sends data one bit at a time, over a single wire.
A standard IDE/EIDE drive cable has 40 wires.
Direct Memory Access (DMA) optimizes the I/O transfer speed in a computer.
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Extended Industry Standard Architecture (EISA) is a 32-bit PC expansion bus designed as a superset of the 16-bit ISA bus.
The computer does not show the correct date and time, every time the system is started. This is because of the failure of the CMOS battery.
The Dual inline memory module (DIMM) has 168 pins.
The Industry Standard Architecture (ISA) bus has an 8-bit and a 16-bit bus that supports both 8-bit and 16-bit cards.
The Master/Slave designations can be assigned by setting a jumper on the hard disk drive.
An I/O address is a communication port between a device and the CPU.
A hard disk controller uses the I/O address range 1F0-1F8.
Micro Channel Architecture (MCA) uses a 32-bit data bus, which is designed by IBM.
A modem converts digital signals into analog signals and vice versa.
IRQ 15 is usually used by a Secondary hard disk controller.
Pentium processors with 321-pins use Socket 7.
I/O address is a communication port between a device and the CPU. It is a hexadecimal number that the CPU uses to identify a device.
Rambus Inline Memory Module (RIMM) and Dual In-line Memory Module (DIMM) both come in 184 pins.
Zero Insertion Force (ZIF) socket holds the microprocessor on the motherboard. It has a lever that opens and closes for holding the microprocessor.
SIMMs are available in two types, 30-pin and 72-pin. SIMM is a memory module with memory chips on one side of the circuit board.
Intel Celeron processors use Slot 1 and Socket 370.
80486 and Pentium processors come in a PGA package. Pin Grid Array (PGA) is a type of integrated circuit chip that consists of pins connected in a square flat package.
SCSI ID 8 provides lowest priority while SCSI ID 7 provides highest priority to a device. The ID priority order on a SCSI bus is as follows: 7, 6, 5, 4, 3, 2, 1, 0, 15, 14, 13, 12, 11, 10, 9, 8.
The 168-pin Dual Inline Memory Module (DIMM) uses 64-bit wide data bus.
A Fast-Wide SCSI-2 bus supports 15 devices excluding the SCSI adapter.
If you have two SCSI devices, internal and external, you should place one terminator at the end of each drive. The SCSI controller will be placed in between the SCSI devices.
Black color wires will be set adjacent to each other while connecting AT power supply to the motherboard.
An AGP slot is designed to provide a direct connection between the video card circuitry and the PC’s memory.
While installing two hard disk drives on a computer, any one of the following two combinations can be used:
- Install the drives, one each on the primary and secondary IDE controllers and designate both as Master.
- Install both drives on the primary IDE controller and designate one as Master and the other as Slave.
Cyrix MII, AMD K6, and Pentium MMX processors use Socket 7.
When a computer’s CMOS battery is replaced, the system clock of the computer is reset. Therefore, your next step after replacing the CMOS battery will be to set the date and time on the computer.
The Itanium processor uses 1.6 volts.
The SCSI Ultra2 Wide I/O port has a bandwidth of 80 MBps.
Riser card is a circuit board that is used to extend slots for expansion cards and provides the ability to connect additional expansion cards to the computer.
Most of Pentium 4 processors use Socket 478.
Xeon processors use Socket 603. It is a Pin Grid Array (PGA) Zero Insertion Force (ZIF) socket.
Pentium II and Xeon processors can be installed on Slot 2. Slot 2 is similar to Slot 1.
The Level 1 (L1) cache is implemented on microprocessors.
A USB host supplies power to the USB bus at 5 volts.
FireWire 800 is a version of the FireWire standard that is also known as IEEE 1394b specification. The FireWire 800 version supports a maximum cable length of up to 4.5 meters.
FireWire 800 devices use 9-pin connectors at both ends of the cable.
The BIOS on a computer should be updated in the following conditions:
- The BIOS does not support new devices.
- Users need to use new hardware features or options that are supported by motherboard, but not supported by the computer BIOS.
- The BIOS can also be updated if a user has a device problem, and it is confirmed that the problem is due to BIOS.
The Pentium 4 processor can be installed on Socket 423 and Socket 478. Both the sockets are old ZIF type sockets and look the same.
The Pentium Pro processor can be installed on Socket 8.
The Pentium D processor can be installed on Socket 478 or LGA 775. LGA 775 is also known as Socket T.
The DIMM is used for DDR SDRAM in desktops.
The memory modules that support 32-bit wide memory bus are as follows:
- 72-pin SIMM
- 72-pin SODIMM
An IEEE 1394 port can connect up to 63 devices. This port is also known as FireWire.
The purple color is used for a PS/2 keyboard connector on new motherboards.
AGP and PCIe are the best slots for a video card.
ATX is a type of motherboard that supports soft power on switch.
A floppy drive power connector has four wires. The red wire carries 5VDC and the yellow wire carries 12VDC. The other two black wires are ground wires.
The CD/DVD drives use 12 and 5 Volts power supply. The hard disk drive also uses the same output voltage.
In the AT power supply connector on a motherboard, Pin 1 is used for Power Good signal.
The memory internal to a processor is called cache memory. It is also known as level 1 cache.
Streaming SIMD Extensions (SSE) was introduced with Pentium III processors. Single Instruction Multiple Data (SIMD) Extensions significantly enhance the performance of 3D graphics.
Level 1 cache memory is integrated with the microprocessor.
The data bus width of an Itanium processor is 64-bit.
The following processors have 64-bit data bus width:
- AMD K6
- Pentium 4
- AMD Athlon
The Pentium 4 processor uses 1.7 volts.
The Level 1 cache is a type of RAM that is included in a CPU. All the commands for the CPU go through the cache. It stores a backlog of the commands so that, if a wait state is encountered, the CPU can continue to process data by using the commands from the cache. It improves computer performance by eliminating the need to wait for data to be fetched from DRAM. The Level 1 cache is also known as internal cache.
Overclocking is the process of running a computer component, such as CPU, at a higher clock rate than specified by the component manufacturer. By increasing clock frequencies of the components, the performance of computers can be improved at very little cost. Users who overclock computer components generally try to enhance the performance of processors, video cards, RAM, and motherboard chipsets. The overclocked components produce excessive heat.
CPU throttling is a process of cutting down the CPU processing time for an application, which is malfunctioning. For example, if a Terminal Server user opens an application that uses 100% of the CPU time, the whole server becomes unresponsive, and other logged in users on the Terminal Server experience a slow performance, then CPU throttling is needed for freeing up CPU time and making the server performance better. In this situation, CPU throttling prevents applications using more than a certain percentage of CPU time in a certain time frame. It provides users a better Server Based Computing experience.
The Intel(r) Pentium(r) processor Extreme Edition and AMD Athlon(tm) 64 X2 are dual core technology processors manufactured by Intel and AMD, respectively.
The following are the types of Random Access Memory:
Parity error indicates a problem with data stored in the memory.
The monitor screen displays dots because of faulty video RAM.
Static Random Access Memory (SRAM) is used for a computer’s cache memory and as part of the random access memory digital-to-analog converter on a video card.
Parity error indicates a problem with data stored in the Random Access Memory (RAM).
An Error Correcting Code (ECC) memory module detects and corrects single-bit errors in memory. It helps a computer to continue working without interruption and data corruption. Although ECC can detect both single-bit and double-bit errors, it can only correct single-bit errors.
Static RAM (SRAM) is a type of memory chip made of a special circuit known as flip-flop. It is significantly faster than DRAM. Unlike DRAM memory chip circuits, it does not have to be refreshed because it uses the flip-flop circuit to store each bit. SRAM memory chips are generally used for caching.
Small Outline Dual Inline Memory Module (SO-DIMM) is a type of memory module that comes in 72 pins and 144 pins.
Video Graphic Array (VGA) monitors have a default resolution of 640×480-pixels.
A laptop uses Liquid Crystal Display (LCD) technology for its display system.
Two types of LCDs are available that are as follows:
- Active matrix
- Passive matrix
The VGA monitor uses a 15-pin 3 row connector to connect to a video adapter.
XT and AT motherboards use 5-pin DIN connectors for keyboards.
Refresh rate measures the time a cathode-ray tube (CRT) electron beam takes to paint a screen from top to bottom.
The following connectors are used for keyboards:
- Five-pin DIN connector
- Six-pin mini-DIN connector
- USB connector
The DVI-D is a type of DVI connector. This connector is used only for digital signal connections. DVI-D connectors come in dual and single links. The dual link connector contains 24 pins, whereas the single link connector comes with 18 pins.
The DVI-I is a type of DVI connector. This connector is used for both digital and analog signal connections. DVI-I connectors come in dual and single links. To carry analog signal, it contains 4 more pins than the DVI-D connector.
The SVGA video technology supports the resolution of 800 x 600.
HDMI stands for High-Definition Multimedia Interface. It is a standard, uncompressed, and all-digital audio/video interface. HDMI is capable of delivering the highest quality digital video and multi-channel digital audio on a single cable. It provides an interface between any audio/video sources, such as a DVD player or a computer and a digital television (DTV) or video monitor.
Small Computer System Interface (SCSI) adapters can fit on PCI, EISA, and VESA slots.
USB provides the Plug and Play capability of Windows to external hardware devices. USB supports hot plugging, which means that a USB device can be installed or removed while the computer is running.
RJ-11 connector is used by an analog modem to connect to a phone line.
Speed, expansion, and easy configuration of hardware devices is the prime benefits of using USB.
The 2x, 4x, and 8x AGP cards each have a bus speed of 66 MHz.
AGP 1x has a maximum data transfer rate of 266 MB/sec.
A parallel printer cable has a DB-25 connector on one end and a Centronics connector on the other end of cable.
A Universal Asynchronous Receiver/Transmitter (UART) chip is a part of the computer’s serial interface, which controls serial port communication.
Universal Serial Bus (USB) can connect up to 127 peripheral devices to a single USB port and it supports hot plugging.
A PS/2 Mini-DIN connector has 6-pins, while only four are used.
In an event of processor fan failure, the heat generated by the processor will cause computer hang up and processor damage.
The fans inside the CPU box throw the hot air out of the CPU box and therefore help in keeping the CPU temperature low. Fans are also used to improve air circulation in the CPU box.
The 6-pin Mini-DIN connector is also known as PS/2 port.
Firewire 800 is the fastest data transfer interface for printing a document on a printer.
In order to prevent laptops from overheating, a user should take the following precautions:
- A laptop should not be operated on a soft surface like bed. It might block the ventilators. This will prevent the hot air from going out of the laptop. A laptop should always be operated on a hard surface.
- Laptops should not be operated in the sun for long periods of time.
A DE15 male connector is used on a monitor cable.
After installing the sound card, restart the computer. You find that another device on the computer has stopped working. This is the symptom of IRQ conflict.
A computer fails to boot from a bootable floppy disk because of any one of the following reasons:
- If the head of a floppy disk drive is dirty, it cannot read the boot files from the floppy disk. This will prevent the computer from booting through the floppy disk. The floppy disk drive should be cleaned using a floppy disk drive head cleaner to resolve the issue.
- If boot sequence in the BIOS is incorrect or is not set to boot from floppy disk first, the computer will not read the operating system file through the floppy disk drive. This will prevent the computer from booting through the floppy disk.
The Dr. Watson utility is used as a program error debugger that gathers information about a computer when an error or user-mode fault occurs with a program.
Disk Defragmenter is a system tool used to consolidate the fragmented files stored on the hard disk of a computer. It helps to improve the read performance of a hard disk drive.
COM1 and COM3 both use IRQ4.
A dirty mouse roller often creates problems in the movement of the mouse pointer.
In order to minimize issues with hard disk drives, users should take the following actions:
- Run the SCANDISK and the drive defragmentation software utilities periodically.
- Do not expose the internal housing of hard disk to open air. In open air, the internal parts and media can come in contact of dust, which might damage them.
- Do not move a hard disk when it is spinning, as this can damage its media.
Device Manager can be used to view and change the properties of devices in a windows computer
When you start the computer, it gives single beep if it has successfully completed the Power On Self Test (POST).
A BIOS upgrade is required if you want to install a high capacity hard disk drive on an older machine, which is not supported by an older BIOS.
You can start the CMOS setup program by pressing the Del key or Ctrl Alt Esc at the time of system startup during Power On Self Test (POST).
Error codes beginning with 2xx indicate problems related to memory.
You can reset the BIOS password using any one of the following two methods:
If your computer is not connected to the UPS, power failure may cause damage to peripheral components. You can avoid such problems by using UPS and surge protector.
You can find the BIOS version ID in the BIOS setup program.
Error codes starting with 6xx indicate problems related to floppy disk drive.
Error codes beginning with 3xx (300 to 399) indicate keyboard errors.
Error codes beginning with 2xx indicate problems related to memory.
In the IBM BIOS, two short beeps indicate a POST error.
In the IBM BIOS, one long beep and three short beeps indicate a video adapter error.
IBM ThinkPad laptops give 1 long and 4 short beeps to indicate low battery voltage.
2xx error codes are used for memory or RAM related errors.
The ROM BIOS is a type of chip, which is plugged in on the system’s motherboard and performs the Power On Self Test.
The video adapter has its own Basic Input Output system (BIOS), processor, and memory.
Isopropyl alcohol is recommended for cleaning PCBs, such as motherboards.
In order to clean electronic connectors and add-on cards of computers, Isopropyl alcohol is used. This removes oxidation from the connectors and pin contacts of PCBs.
The Nickel-cadmium (NiCd) battery has the shortest life that of those Lead-acid and Silver-zinc batteries. This battery has a nominal voltage of 1.2 volts.
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Laptops and Portable Devices
Type III Personal Computer Memory Card International Association (PCMCIA) card supports hard disk drives.
To improve the quality of connections and achieve better communication between infrared devices, you will have to take the following actions:
- Keep the devices in line of sight.
- Move the devices closer together.
- Remove any obstruction between the devices.
Type I Personal Computer Memory Card International Association (PCMCIA) cards are 3.3mm thick. They are most commonly used for memory cards.
A docking station is a specialized case into which an entire laptop can be inserted. This allows a laptop to connect to desktop I/O devices such as full-sized keyboards, CRT monitors, etc. Docking stations are highly proprietary items that are designed for use with specific computer models.
Expansion bus is a collection of wires and protocols used for the expansion of a computer. It connects expansion cards such as network interface card, video card, etc., to system bus. Expansion cards connect to the expansion bus through the expansion slot.
WUXGA stands for Widescreen Ultra extended Graphics Array.
The SXGA display standard has a resolution of 1400 x 1050 pixels. It is an enhancement SXGA display standard.
Type II Personal Computer Memory Card International Association (PCMCIA) card is mostly used for modem and network interface cards.
The SO-DIMM memory package is used for DDR memory for laptops.
The XGA video technology supports a maximum resolution of 1024 x 768.
SXGA stands for Super extended Graphics Array. It is a display standard that refers to video adapters. This standard is an enhancement of the standard XGA resolution developed by IBM. It is capable of displaying the resolution of 1280 x 1024 pixels.
UXGA stands for Ultra extended Graphics Array. It is a display standard that refers to video adapters. This display standard is capable of displaying the resolution of 1600 x 1200 pixels.
The WUXGA video technology supports the maximum resolution of 1920 x 1200. Where 1920 refers to horizontal pixels, and 1200 refers to vertical pixels.
The infrared devices do not encrypt data transmission.
Following are the differences between desktop and laptop processors:
A laptop microprocessor generates less heat than a desktop microprocessor.
A laptop microprocessor consumes less power than a desktop microprocessor.
In order to connect peripheral devices such as printer and mouse to a laptop, bluetooth is the best wireless technology.
An SPS device provides protection against under voltage. When a power drop occurs, it engages battery power and takes over from power outlets. SPS does not provide protection against power surges.
USB and IEEE 1394 ports support hot swapping.
The hot swap technology is used to install a new device, or remove and replace a failed device, without shutting down the operating system or powering off the system.
The Advanced Configuration and Power Interface (ACPI) is a power-management specification developed by Intel, Microsoft, and Toshiba. It enables an operating system to control the amount of power supplied to each device attached to a computer by turning off peripheral devices when they are not in use. It defines power management on a wide range of mobile, desktop, and server computers and peripherals.
The Hibernate mode and Standby mode are features related to power management.
Standby mode has a shorter wake-up period than Hibernate mode. Unlike Hibernate mode, in Standby mode, the contents of the computer’s main memory are not saved to the hard disk, and the operating system need not read contents from the hard disk each time the computer is restarted. Therefore, Standby mode takes lesser amount of time to wake-up as compared to Hibernate mode. Moreover, a computer in Standby mode does not consume any hard disk space.
Hibernate mode saves maximum battery power while maintaining the current state of a computing session.
The S1 mode is the most power hungry sleep mode. In this mode, the CPU stops executing instructions and the processor cash is flushed, but power is still supplied to the CPU and memory. All other unused devices are powered down.
The S4 sleep mode is also known as Hibernation or hibernate mode in Windows operating systems.
The C0 processor state does not save power. It is an operational state.
In the G3 state of a computer, a complete power loss occurs such as power cord unplugged from a computer. A computer can be disassembled in this state.
Li-Ion or Lithium Ion battery is the lightest but most expensive battery used in laptops.
A computer makes continuous short beeps while booting if a key on the keyboard is stuck.
If the keyboard is not working even after replacing it with a new one, it is possible that the keyboard controller on the motherboard is faulty.
A defective monitor or a bent pin on the monitor connector can be a cause of displaying only pink or green color shades on the screen.
A USB port supports up to 127 devices.
When IBM BIOS generates one long and three short beeps, it indicates that the EGA/VGA display adapter has an error.
Power surge is a sudden increase in electric line voltage. A surge can harm a computer and other electronic devices.
The most likely cause of interference in mouse pointer movement could be a dirty mouse roller or track ball. Dirty mouse rollers are responsible for erratic mouse pointer movement.
The Display Power Management Signaling (DPMS) standard is used to control monitors and video cards.
A brownout is the situation of voltage drop in power supply. The overloading of a primary power source can cause brownouts.
Power for the most laptop’s LCD screen backlight bulb is supplied by an inverter.
If the power cable runs along with the computer network cable, radiation from the power cable, known as electromagnetic interference (EMI), may be inducted into the computer network cable affecting the signals that pass through it.
In order to clean a laptop screen, you will have to use a slightly wet and soft cloth and a cleaner that is specially designed for LCD screens.
Operating Systems
Virtual memory is method that is used to store temporary RAM data in the hard disk.
The HKEY_USERS hive contains information about all users who have logged on to the system.
The HKEY_LOCAL_MACHINE registry hive contains information about the local computer system, including hardware and operating system data, such as bus type, system memory, device drivers, and startup control parameters.
The /s switch of the XCOPY command is used to copy directories and subdirectories, except empty directories.
The /o switch of the XCOPY command copies file ownerships and NTFS permissions on files while copying them.
The /e switch is used with the XCOPY command to copy directories and subdirectories, including empty directories.
The /c switch of the XCOPY command continues to copy files even if errors occur.
The /k switch of the XCOPY command copies attributes while copying files. By default, this command resets the Read-only attribute.
The Mac OS X operating system operates on the UNIX kernel platform.
The HKEY_CLASSES_ROOT registry hive stores information about the file extensions mapped to their corresponding applications.
The HKEY_CURENT_USER registry hive stores the user profile for the user who is currently logged on to the computer. The user profile includes environment variables, personal program groups, desktop settings, network connections, printers, and application preferences.
In order to modify virtual memory settings on his Windows 2000 computer, administrators will have to take the following steps:
Go to Start menu > Settings > Control Panel.
Double click the System applet and select the Advanced tab. Click the Performance options, and click the Change button in Virtual memory area.
The Hardware Compatibility List (HCL) contains the listing of all the hardware that operating systems vendors have tested with their operating systems. Through HCL, an administrator can be sure that a computer and its components are compatible with the operating system before the operating system is installed.
Automated System Recovery (ASR) is a feature of Windows Server 2003. It is used to perform a restore of the system state data and services in the event of a major system failure. An ASR restore includes the configuration information for devices. ASR backs up the system data and local system partition. It does not back up folders and files.
Event Viewer is an administrative utility that displays the event log of a computer. The following logs can be viewed using the Event Viewer tool in Windows 2000/XP computers:
- System log
- Security log
- Application log
The System Configuration Utility (MSCONFIG.EXE) is available on Windows 98 and Windows XP operating systems.
The following tabs are available in the Task Manager window in Windows XP operating system:
- Applications
- Processes
- Performance
- Networking
- Users
The following tabs are available in the Task Manager window in Windows 2000 operating system:
- Applications
- Processes
- Performance
Following are the files required to boot Windows NT 4.0:
- NTLDR: This is the Windows NT boot loader program. This is the first file to get executed during a boot process.
- BOOT.INI: This file describes the location of the boot partitions specified by using Advanced RISC Computing (ARC) naming conventions.
- NTDETECT.COM: This file is used for hardware detection.
- BOOTSECT.DOS: This file is used to dual-boot a computer. It takes control from NTLDR if a user chooses a non-Windows NT operating system from the boot loader menu.
- NTBOOTDD.SYS: This file is required only if the scsi() syntax is used in the BOOT.INI file. It is not present in the root folder if the multi() syntax is used.
NTDETECT.COM: is a startup file of the Windows NT/2000 operating system. It is located in the root of the startup disk and is used to gather information about currently installed hardware on the computer.
In Windows operating systems, the Systray.exe is a tool that holds icons for programs running in the background.
The WINMSD utility is also known as System Information utility.
The message “NO ROM BASIC, SYSTEM HALTED” appears on a computer when you do not select an active partition on the hard disk drive. You have to select an active partition in addition to partitioning and formatting your hard disk.
When a backup taken in an NTFS partition is restored in a FAT32 partition, the following file properties are retained:
- Long file names
- File attributes
- Encryption, permission, and compression are lost, as the FAT32 file system does not support these features.
The RD command is used to delete or remove a directory.
An extended partition is a container for logical partitions. These logical partitions are formatted and assigned drive letters. An extended partition neither be formatted, nor can it be assigned a drive letter. It can be sub-divided into logical drives.
The CD.. command is used to change to the parent directory.
The /q switch of the DIR command displays the owner of a file.
The /s switch of the DIR command displays files in a specified directory and all its subdirectories.
The DIR /on command lists files in alphabetical order by their names.
The FORMAT command is used to format disks. The FORMAT a: /q command performs a quick format on a floppy disk. This command completely removes data on the disk that is formatted.
Windows Explorer is a graphical tool used to navigate through directory structures.
The Disk Management tool is used to create partitions and format new disks.
A floppy disk drive can be connected to a 34-pins connector on an I/O card.
The most likely cause of the Invalid System Disk error message on a computer is that a non-bootable floppy disk is inserted in drive A:.
The master boot record location on the hard drive is Cylinder 0, Head 0, and Sector 1.
Windows 2000 operating system supports the following files systems for the hard disk drive:
The Windows 2000 Readiness Analyzer (CHKUPGRD.EXE) is a tool that can be used to generate the upgrade compatibility report. This report confirms whether or not the devices and drivers on an existing operating system are compatible with Windows 2000.
Before performing the upgrade from Windows 98 SE to Windows 2000 Professional, you should take the following steps:
Verify that each component of the computer is in the hardware compatibility list (HCL).
Verify that the client computer meets the minimum requirements for Windows 2000 Professional.
The hard disk, video adapter, and sound card are the devices that move large blocks of data and therefore, require access to a DMA channel.
IRQ6 is used by the floppy disk controller.
Recovery Console is a command-line console that enables administrators to repair a computer in the event a user cannot start the computer by using the safe-mode boot option. Unlike safe mode, Recovery Console does not have a graphical user interface and is completely command-line driven. Recovery Console helps in recovering from boot-related problems, such as when a Windows 2000 computer does not start. It allows limited access to the NTFS, FAT, FAT16, and FAT32 volumes without starting the graphical interface. From Recovery Console, administrators can start and stop services, read and write data on a local drive, repair the master boot record (MBR), format drives, and perform other administrative tasks. Recovery Console also prevents unauthorized access to volumes by requiring the user to enter the system administrator password.
The FIXMBR command is a tool of Recovery Console in Windows 2000. It is used to repair the master boot code of the boot partition.
The FIXBOOT command is a tool of Recovery Console in Windows 2000/XP. This command is used to repair a corrupt boot sector by writing a new boot sector on the system partition.
In order to get advanced startup options during startup of a Windows 2000 computer, the F8 key should be pressed.
Automated System Recovery (ASR) is an advanced option of the Backup tool. It restores the last system backup taken through the ASR backup utility.
The ATTRIB command uses the switch to set attributes on files.
The ATTRIB command uses the – switch to clear the attributes of a file.
In order to set the hidden attribute on the file, you will have to run the following command on the command prompt: ATTRIB h DATA.TXT
MSCONFIG is a utility that automates the routine troubleshooting steps that service technicians take when they diagnose Windows configuration issues. It is used to troubleshoot issues that arise during startup, to discover and resolve issues with running services, or to eliminate errors regarding the boot path configured on multiple computers.
Printers and Scanners
ECP, EPP, and SPP are types of parallel ports.
When you install a SCSI adapter on your system to control, both, external and internal devices, the terminating resistor must be disabled on the adapter. Also, terminate both the last internal and last external devices.
To take advantage of bi-directional printing, you must have an IEEE 1284 specification compliant printer cable, a bi-directional printer, and a correctly configured port.
IEEE 1394 is a high-speed serial bus that provides enhanced PC connectivity for a wide range of devices.
The jumper settings on the network interface card are used to configure I/O address.
Joystick connector is a 15-pin two row female connector used to connect a Joystick to a computer.
The maximum cable length to connect a device to an IEEE 1394a port is 4.5 meters.
In a laser printer, the laser beam hits the surface of the photosensitive drum to draw the image, which is to be printed on the page.
Line and dot matrix printers can print multipart forms at a time.
The IEEE 1284 port transfers data at high speed to printers only.
The corona wire is a component that charges the EP drum of a laser printer.
Printers use languages such as PCL, PostScript, and Windows Graphical Device Interface (GDI ).
Garbage printing occurs due to a wrongly configured printer driver. To resolve such issue, you will have to run the Add Printer Driver Wizard to install the correct printer driver on your computer.
Fuser is a part of a laser printer that has high temperature. Users should avoid touching it.
The vertical black line on the printed paper is due to the toner cartridge being nearly empty. To resolve the issue, you will have to shake the toner cartridge so that the toner is redistributed.
The toner spreads over the paper when the fuser roller is not heated properly. Due to low heating of the roller, the toner does not melt. As a result, it does not stick to the paper.
A dirty fuser roller of a laser printer can be the cause of a series of black spots on the printed paper at regular intervals. To resolve the issue, you will have to clean the fuser roller.
In a laser printer, the primary corona charges the photosensitive particles on the surface of the drum. It charges the drum with a negative charge.
In a laser printer, the transfer corona charges the surface of the paper with a positive charge.
The carriage motor moves the printhead left and right in a dot matrix printer.
Networks
An unshielded twisted-pair connection uses an RJ-45 connector.
Star topology is a type of physical network design where each computer in the network is connected to a central device, called hub, through an unshielded twisted-pair (UTP) wire.
Category 5 UTP cable is used for data transmissions up to 100 Mbps. It consists of four twisted-pairs of copper wire.
BNC T connectors, BNC terminators, and BNC barrels are used with coaxial cables.
Repeater, hub, brouter, and bridge are network connectivity devices.
10BaseT Ethernet cable uses 8-pin make connector.
Bus topology uses a 10Base2 cable.
RJ-45 connector is used to connect a 10BaseT Ethernet cable to an NIC on a desktop computer.
There are three types of serial interfaces: Standard, Universal Serial Bus (USB), and FireWire.
Ethernet uses CSMA/CD technology.
Active hub extends a network on a purely mechanical basis.
The maximum cable segment length supported by a 10BaseT network is 100 meters.
RJ-45 connectors is used to connect a twisted-pair cable to a network adapter card.
Fiber-optic cable uses optical fibers to carry digital data signals in the form of modulated pulses of light.
Routers prevent broadcasts from crossing over subnets.
Fiber-optic cable is used for high-speed, high-capacity data transmission. It uses optical fibers to carry digital data signals in the form of modulated pulses of light.
ST and MT-RJ are fiber optic connectors used in gigabit Ethernets.
The MT-RJ connector is the most recent type of small form factor fiber optic connector. It also supports full duplex and is easier to terminate and install as compared to an ST or SC connector.
Synopsis [1381] The Institute of Electrical and Electronic Engineers (IEEE) formed a project, called Project 802 to help define certain LAN standards. Project 802 defines aspect of the network relating to physical cabling and data transmission, corresponding to the physical and data link layers of Open System Interconnect (OSI) model. The 802 specifications contain twelve different categories. In these specifications, 802.8 defines standards for fiber-optic cable.
A straight tip (ST) connector is a fiber-optic connector used with multimode fiber. An ST connector has a 2.5mm shaft and bayonet locking ring, and allows quick connect and disconnect of 125 micron multi-mode fiber.
100BaseT network uses Cat 5 UTP cables.
MultiMode Fiber (MMF) is a type of fiber-optic cable. A fiber optic cable does not require terminators.
The MT-RJ and LC connectors can be used with the SFF fiber-optic cables.
Mesh is the most fault tolerant network topology.
Institute of Electrical and Electronics Engineering (IEEE) specification 802.3 defines standards for Ethernet.
Active hub can resolve the signal strength deterioration problem.
IEEE 802.11b is an extension of the 802.11 standard. It is used in wireless local area networks (WLANs) and provides 11 Mbps transmission speeds in the bandwidth of 2.4 GHz.
The maximum segment length of a 10BaseT Ethernet network is 100 meters.
Bluetooth uses the frequency of 2.4 GHz.
Bluetooth is a standard for very low powered and short-range radio connections. It is used to link personal access devices (PDA), mobile phones and laptops, and provides them with Internet access via hot spots.
Bluetooth is a standard for very low powered and short-range radio connections. As a radio technology, it does not require a line-of-sight connection as an infrared connection does. The maximum transmission range of Bluetooth is around 10 meters.
10Base5 can transmit data up to a distance of 500 meters.
2.4 Ghz spectrum is used by Bluetooth for transmission of data.
The maximum segment length that a 1000BaseT network supports is 100 meters.
802.1X specification defines the authentication method for wireless access.
The maximum length of the cable segment in a 1000BASE-SX network is 550 meters.
The maximum data transfer rate that can be achieved by implementing the 802.11g wireless standard is 54Mbps.
A long length of antenna extension cable and the 2.4GHz interference can affect the range of the network.
The 802.11g standard, defined by IEEE, is an extension to the 802.11b standard of wireless network. It operates in 2.4-GHz band and brings data rates up to 54Mbps using Orthogonal Frequency-Division Multiplexing (OFDM) technology.
100BaseTX cabling can have a maximum segment length of 100 meters.
100BaseFX is a fast Ethernet network that runs at the speed of 100 Mbps using Multimode Fiber-optic (MMF) cable with segment lengths of up to 412 meters for half duplex connections and 2000 meters for full duplex connections.
An external antenna with the WAP increases the range of the wireless access point.
The maximum data transmission speed for IEE 802.11b standard is 11Mbps.
A bad or noisy phone line can create problems in establishing a connection with your ISP computer.
NETSTAT is used to show the state of current TCP/IP connections.
PING is used to verify the existence of a host in a network.
The TRACERT utility traces the path taken by TCP/IP packets to a remote computer.
NBTSTAT -n displays the list of local NetBIOS names.
Time Domain Reflectometer (TDR)is used to detect breaks in network cables.
The NETSTAT -s command displays the statistics of each protocol installed in a computer.
The ARP command displays and modifies the IP-to-physical address translation tables used by the Address Resolution Protocol (ARP)
The 802.11b wireless standard applies to wireless LANs and provides transmission speeds of up to 11 Mbps in the 2.4 GHz frequency. Its network range is up to 150 feet.
To use the smart cards for remote access authentication, you will have to take the following steps:
- On the remote access client computers, enable the smart card authentication on the dial-up connection.
- On the Routing and Remote Access server, install a smart card logon certificate.
- Enable the Extensible Authentication Protocol (EAP) check box.
- The use of smart cards for user authentication is a strong form of authentication.
Although it may seem obvious, one of the first places to look when troubleshooting logon problems is to verify that the Caps Lock key is off.
The first step to resolve a password issue is to make sure that the Caps Lock key is off. This is the most common problem that occurs while logging on to a server. If this does not help, then you should check for the connectivity issues.
100% packet lost in output generated through PING shows that there is no connectivity between the source and the destination computer.
If pinging the server’s own loopback address fails, it shows that the server’s NIC is not working.
Security
The following actions can result in a virus attack:
- Using a floppy from unreliable source.
- Downloading file(s) from the Internet.
A computer case does not need to be recycled because it does not contain materials that are harmful for the environment.
Smart card is a device that contains a microprocessor and permanent memory. It is used to securely store public and private keys for log on, e-mail signing and encryption, and file encryption.
How to configure a wireless LAN to provide security? Set the authentication type for the wireless LAN to Shared Key. Disable SSID Broadcast and enable MAC address filtering on all the wireless access points. On each client computer, add the SSID for the wireless LAN as the preferred network.
In order to secure wireless networks, use techniques such as closed network, SSID spoofing, and MAC address filtering.
Only users with the correct WEP key can authenticate from the access point of the network.
Wired Equivalent Privacy (WEP) is a security protocol for wireless local area networks (WLANs).
The Wired Equivalent Privacy (WEP) and Wi-Fi Protected Access (WPA) provide data confidentiality services by encrypting the data sent between wireless systems.
The Static IP addressing is the term used for manual assignment of IP addresses to computers and devices.
Definition is an anti-virus software file that should be updated at regular intervals to protect a computer from new viruses. This file is also known as virus definition file.
A computer technician will have to do the following to protect the client computers from malware:
- Educate users of client computers about the problems arising due to malware.
- Educate users of client computers to avoid malware.
FAT32 does not support dual-booting with MS-DOS or Windows NT 4.0. Once FAT16 is converted to FAT32, you cannot convert that partition back to FAT16. FAT32 is supported by Windows 98 and Windows 2000 operating systems only.
Following are the types of social engineering attacks:
- An unauthorized person calls a user and pretends to be a system administrator in order to get the user’s password.
- An unauthorized person gains entrance to the building where the company’s database server resides and accesses the server by pretending to be an employee.
Asymmetric algorithm uses two keys, public key and private key, to encrypt and decrypt data.
Symmetric algorithm uses a single key, referred to as private key, to encrypt data.
If you want that whenever he boots his computer, the computer should first search for the boot files on the floppy disk drive and then switch to IDE master hard disk drive. In order to do that, change the boot sequence to A:, C: in the BIOS.
The following can be configured in the BIOS:
- Hard disk drive parameters
- Floppy disk drive parameters
- Boot sequence
- Shadow RAM
- Date and time
Shadowing is a method that improves system performance by copying code in ROM BIOS to the extended memory of a computer.
Older BIOS cannot support a hard disk having more than 504 MB capacity. In this situation, an upgrade of BIOS is required.
Authentication is a process of verifying the identity of a person, network host, or system process. The authentication process compares the provided credentials with the credentials stored in the database of an authentication server.
Password Authentication Protocol (PAP) transmits user credentials as plaintext.
Multi-factor authentication involves a combination of multiple methods of authentication. For example, an authentication method that uses smart cards as well as usernames and passwords can be referred to as multi-factor authentication.
Following are the advantages of the FAT32 file system over FAT16 file system:
- It supports drives up to 2 terabytes (TB) in size.
- It allocates disk space more efficiently.
Safety and Environmental Issues
Polyvinyl chloride (PVC) is a type of plastic used to construct the insulation and the cable jacket for a cable.
Before removing a computer case, you should first shut down the computer and turn off the power connection. Otherwise, you can get a lethal shock.
A Material Safety Data Sheet (MSDS) is a document that specifies a set of guidelines regarding the proper handling, transporting, storage, and disposal of a hazardous substance or chemical. It also contains information on first-aid treatment, as it is helpful in case of accident or exposure to toxic material.
Class C fire extinguishers are needed for electrical fire. Electrical fire involves electrical equipments, such as appliances, wiring, and circuit breakers. The class C extinguishing agent is non-conductive.
Class B extinguishers are needed for flammable or combustible liquids’ fire such as gasoline, kerosene, grease, and oil.
A computer monitor and SMPS are at high voltage. Therefore, these devices can be fatal. They usually have large amount of electric charge stored in capacitors for days after they have been unplugged from power source.
Low humidity increases the risk of Electrostatic discharge (ESD).
Damage of electronic components can occur in a high humidity environment.
You should wear a wrist strap when you are working on computer components. It minimizes Electrostatic Discharge (ESD) problems.
Electrostatic Discharge (ESD) occurs when two objects of different electric potential come in contact with one another and exchange the charge in order to standardize the electrostatic charge.
As a precaution, you should always wear the wrist strap attached to the computer case while installing a video-card. Wrist strap provides protection against Electrostatic discharge (ESD) that can damage electronic components, such as, chips on the motherboard or adapters. The wrist strap maintains charge equalization between your body and the computer parts.
Cathode Ray Tube (CRT) monitors and SMPS can pose the risk of electrocution, as they contain capacitors.
In order to minimize the risk of damage to add-on cards and motherboard, users should take the following precautions:
- Keep them in antistatic bags whenever they are removed from the computer. Antistatic bags protect them from static charges.
- Keep water and liquids away from electronic circuits, as they might cause short circuits.
- Wear antistatic wrist strap while handling or repairing a computer. The antistatic wrist strap prevents static electricity from building up.
- In order to reduce the chances of static charges being built up, users or technicians will have to take the following steps:
- Wear cotton clothes. This will reduce the chance of building up of static charges.
- Do not cover the computer room’s floor with carpets. This stops neutralizing of static charges.
- Increase humidity level. Humidity helps dissipate static charges.
The following types of batteries are considered as environmental hazards:
- Nickel cadmium (NiCd)
- Lead-acid
- Button cell
Nickel cadmium (NiCd) batteries contain nickel and cadmium. Cadmium is highly toxic.
Communication and Professionalism
In order to maintain professional behavior as a computer service technician, you are supposed to do the following:
- Avoid being insulting or calling a customer by his name.
- Avoid arguing with customers.
- Always maintain a positive attitude and tone of voice.
- Avoid disturbance or interruption while talking to customers.
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