Bài giảng Computer - Chapter 19

Chapter Overview The Right Tools for the JobPlanning and Performing Regular MaintenanceMaintaining the Windows System Environment 1Assembling a Complete Toolkit Good preparation can save hours of guessing and frustration.A complete toolkit includes the following: Hardware toolkitSoftware toolkitSpare partsTechnical library 2Hardware Toolkit ScrewdriversTorx driverNut driverTweezersNeedlenose pliersChip removersTube or plastic bagCompressed air Electrostatic discharge (ESD) toolsMultimeterFlashlightHemostatsPower-on self test (POST) cardLaptop computer and phone cordBlank floppy disks3Software Toolkit Bootable floppy disk with essential filesAdditional files on disk as needed Operating system disksSoftware utilities 4Spare Parts Power supply1.44-MB floppy disk driveDisplay cardCablesGoodie bag 5Technical Library Documentation and manualsNotes and research from previous jobs and technical trainingOther resources, such as Microsoft TechNet 6Outside Resources Attend seminars and get further technical training.Network with colleagues, using e-mail and newsgroups.Search the World Wide Web.Locate private Internet forums specific to your interests.Practice to keep your skills sharp.Read technical books, magazines, and e-zines. 7Technical Support TelephoneGenerally for novice and home usersMore effective if you have the problem computer in front of you when you callUsually provided free for a limited time only Online Web sitesOnline forumsTroubleshooting wizards 8Working Safely9Power and Safety Power is the primary safety hazard in servicing computers.ESD can destroy sensitive equipment.A properly grounded computer prevents transmission of electromagnetic interference (EMI).High voltages often exist in power supplies and monitors. 10Guidelines when Working with Computer Equipment Avoid wearing jewelry.Do not use liquids around electrical equipment.Do not use 3 prong-to-2 prong power plug adapters.Replace worn or damaged power cords immediately. Do not rest anything on a power cord.Avoid using extension cords.Keep electrical covers intact.Keep air vents clear.Do not remove covers from high-voltage items unless absolutely necessary. 11Fire If a fire is not extinguished within 30 seconds, exit the building and then call for help.Know the emergency procedures at your workplace.Know the nearest fire exits and the location of fire extinguishers.Know how to use the right fire extinguishers for each type of fire.Avoid overloading electrical outlets. 12Environmental Issues BatteriesToner and cartridge kitsCircuit boardsChemical solventsMonitors (cathode-ray tubes, or CRTs) 13Developing Maintenance Plans and Procedures Develop and document logical plans and procedures for every class of computer and operating system in your organization.Develop a regular maintenance plan.Automate tasks where possible.Keep proper records. 14Cleaning A computer-friendly environment is basically dust-free, smoke-free, well-ventilated, and temperature- and humidity-controlled.Clean non–computer-friendly areas more frequently.Try to improve non–computer-friendly environments.Assemble a basic cleaning kit. 15Monitors Periodically clean and dust monitors.Use simple cleaning solutions such as one drop of dishwashing liquid in one quart of water. Do not use sprays, solvents, or commercial cleansers.Use a screen saver or power-conservation features.Do not work inside a monitor cabinet unless specifically trained.Do not change settings or operate the monitor with the cover removed. 16Hard Disk Drives Avoid rough handling.Do not move the hard disk drive while platters are spinning.Do not expose hard disk drive internals to open air and dust.Perform regular data backups and disk maintenance tasks. 17Floppy Disk Drives Guard against environmental and mechanical damage.Replace rather than fix floppy disk drives.Do not expose disks to magnets.Do not touch the surface of a floppy disk.Avoid smoking near a computer.Clean read/write heads with special head-cleaning disks and solutions. 18Keyboards and Pointing Devices Keep keyboards and pointing devices clean to prolong their life.Avoid drinks around keyboards.Use a handheld vacuum to clean dust from keyboard crevices.Avoid spray cleaners.Remove the ball of a mouse or trackball and clean the rollers. Avoid touching the end of a light pen. 19Dot-Matrix Printers Adjust print-head spacing and tension on the print-head positioning belt.Clean the print head, roller surfaces, platen, and gear train of the paper-handling motor.Lubricate gears with light oil on a foam swab and turn the platen to distribute oil.Lubricate rails with light oil and move the carriage assembly to distribute oil. 20Ink-Jet Printers Adjust the print-head spacing and tension on the print-head positioning belt.Clean the printer and its mechanisms, roller surfaces, the platen, the ink-jet print head, and the gear train of the paper-handling motor.Lubricate gears with light oil on a foam swab and turn the platen to distribute oil.Lubricate rails with light oil and move the carriage assembly to distribute oil. 21Laser Printers Vacuum to remove dust and toner buildup from the interior.Clean rollers with a damp cloth and clean the gear train with a foam swab.Lubricate gears with light oil and distribute oil through the gear train.Clean the writing mechanism thoroughly with compressed air.Wipe the laser lens with lint-free wipes to remove fingerprints and stains.Clean the corona wires with a foam swab dipped in alcohol. 22Preventive Maintenance Schedule23Preventive Maintenance Schedule (Cont.)24Types of Viruses File infectorsBoot sector virusesTrojan horsesMacro virusesPolymorphic viruses 25Guidelines for Antivirus Programs Get the right version for the operating system.Consider enabling the basic input/output system (BIOS) setting that disables boot-sector writes.Use caution with unknown floppy disks and computers.When connected to the Internet, run an antivirus program at all times.When loading programs, trust no one.Keep the antivirus program updated. 26Disk Cleanup27Using Scandisk for Drive Integrity28Organizing Files with Disk Defragmenter29File Backups Data loss is inevitable because drives fail and critical files become corrupt.Developing a good backup plan is one of your most valuable services.Automating backups wherever possible ensures that they happen.Microsoft Windows ships with a built-in backup program.You can back up to tape, another hard disk drive, or removable media. 30Backup Types 31Backup Plan Issues Select hardware based on the amount of data and frequency of backup.Use different backup types to balance backup and restore times.Use normal backup at regular intervals, with incremental or differential backups between normal backups. 32Backup Plan Gotchas Store backup copies in a safe, environmentally sound location.Make sure copies are secure.Keep long-term backups as protection against virus attacks.Make sure that critical files are not open at backup time.Make sure that new backup components work with old backup copies. 33Using Windows Backup Tools 34Backing Up Registry and Core System Files In Microsoft Windows 2000 and Microsoft Windows NT, select the System State option. This option requires proper permissions.System state data can only be backed up locally. In Microsoft Windows 98 and Microsoft Windows Me, use the Registry Checker command-line application. 35The Windows System File Checker Tracks changes to all system files and ensures that any replacement files are validNotifies the system administrator when improper file replacement is attemptedVerifies the integrity of system filesExtracts and replaces corrupt or missing files 36Creating ERDs and Startup Disks All Windows 98 installations should have a startup floppy disk. The same startup floppy disk can be used on multiple computers.A startup disk can be created using Add/Remove Programs in Control Panel. All Microsoft Windows 2000 installations should have an ERD.An ERD can be used only on the computer it was created for.An ERD can be created using the Windows 2000 backup utility. 37Chapter Summary Assemble a complete toolkit.Advance your skills.Practice preventive maintenance.Develop a backup plan.Protect against viruses.Regularly test, repair, and defragment the hard disk drive and the file system. 38