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• Types of computer system error

  • No Video Output (LED indicator flashing yellow)
  • No Video Output (LED indicator steady orange)
  • Doesn't Boot
  • Never Ending Loading of Operating system
  • Lots of pop up windows showing on standby mode
  • Lots of hardware installation windows appear
  • Safe mode doesn't work
  • Keyboard and mouse system restart
  • Sound on/off error
  • Application causes system to restart
• Different Operating System (OS) errors

  • System errors
  • Runtime errors
  • Stop errors
  • Device Manager Errors
  • POST code errors
  • Application errors
  • Browser Status Codes
• System errors


  Moderately dangerous types of errors caused by malfunctioning hardware components, corrupted operating system modules, etc.
• Runtime errors


  Caused by corrupted or malfunctioning system files or software executables, usually causing the application to shut down
• Stop errors


  Caused by corrupted hardware, especially malfunctioning RAM modules and bad sectors on hard disks, can be difficult to resolve
• Device Manager Errors


  Usually caused by corrupted driver files or malfunctioning hardware components, can often be solved by reinstalling/updating drivers or replacing hardware
• POST code errors


  Caused by malfunctioning hardware components, characterized by short beep sounds from the motherboard speaker
• Application errors


  Caused by applications while they are running
• Browser Status Codes


  Caused by problems faced by browsers when trying to access a website, can be due to misplaced web pages or connection problems
• Types of computer system error

  • No Video Output (LED indicator flashing yellow)
  • No Video Output (LED indicator steady orange)
  • Doesn't Boot
  • Never Ending Loading of Operating system
  • Lots of pop up windows showing on standby mode
  • Lots of hardware installation windows appear
  • Safe mode doesn't work
  • Keyboard and mouse system restart
  • Sound on/off error
  • Application causes system to restart
• Different operating system (OS) errors


  • System errors
  • Runtime errors
  • Stop errors
  • Device Manager Errors
  • POST code errors
  • Application errors
  • Browser Status Codes
• File maintenance


  The routine changes, updates, copying, moving, or deleting of files on a computer
• Things to do to protect files

  • Backing up files
  • Restoring files
  • Using backup media
  • Full backup
  • Incremental backup
• Backup


  Duplicate copy of a file, program, folder or disk used if the original is damaged, corrupt or lost
• Restore


  To copy the backed up version of information back to its original location
• Backup media


  Another computer, CD(s), DVD(s) or any other recordable computers
• Full backup


  Backing up everything on your computer, including data, software and operating system
• Incremental backup


  Backup of only what has changed since the last backup
• Malicious software


  • Virus
  • Worms
  • Trojans
• Virus


  Malware that propagates by inserting a copy of itself into and becoming part of another program
• Worms


  Computer worms are similar to viruses in that they replicate functional copies of themselves and can cause the same type of damage
• Trojans


  Harmful piece of software that looks legitimate, users are typically tricked into loading and executing it on their systems
• Health and safety regulations for computer technicians

  • Report any accidents
  • Take reasonable care when moving heavy components
  • Not cause any electrical hazards
  • Make sure workstations meet safety requirements
• Health and safety regulations help protect you and others and avoid legal action for unsafe working practices
• If you identify any health and safety problems, you should tell your line manager or the health and safety representative immediately
• The most basic test is to switch the system on to check it starts without errors
• ICT professionals are also likely to use tools and utilities to check that all is well with the system after an installation
• Diagnostic tools


  • Loopback adapter
  • Digital multimeter
  • Toner probe
• Loopback adapter


  Also called a loopback plug, it tests the basic functionality of computer ports
• Digital multimeter


  Tests the integrity of circuits and the quality of electricity in computer components, displays information on an LCD or LED
• Toner probe


  A two-part tool, the toner generates a tone that travels the length of the cable, the probe part traces the cable
• Software diagnostic tools


  • FDISK
  • Disk Management tool
  • FORMAT
  • SCANDISK or CHKDSK
  • DEFRAG
  • DISK CLEANUP
  • SYSTEM FILE CHECKER (SFC)
• FDISK


  A command-line tool that creates and deletes partitions on a hard drive, not available in Windows XP, Vista, or 7
• Disk Management tool


  Initializes disks, creates partitions, and formats partitions
• FORMAT


  Prepares a hard drive to store information
• SCANDISK or CHKDSK


  Checks the integrity of files and folders on a hard drive by scanning the file system, may also check the disk surface for physical errors
• DEFRAG


  Optimizes space on a hard drive to allow faster access to programs and data
• DISK CLEANUP


  Clears space on a hard drive by searching for files that can be safely deleted
• SYSTEM FILE CHECKER (SFC)

  A command-line tool that scans the operating system's critical files and replaces files that are corrupted
• Personal protective devices


  • Anti-static devices
  • Power surge protectors
  • Personal equipment