Computer Maintenance (Dec 2024)

Common PSU Connectors

• P1: A 20-pin or 24-pin connector that provides power to the motherboard. Some PSUs split the P1 into one 20-pin connector and one 4-pin connector, combining them if needed to form a 24-pin connector.
• ATX12V (or P4): A 4-pin or 8-pin power connector that goes to the motherboard, in addition to a 20-pin P1, to supply power to the processor.
• Molex: A 4-pin peripheral power connector that provides power to IDE disk drives and CD-ROM/DVD drives.

"80 Plus" Certification

• A voluntary program to promote efficient energy use in computer power supply units (PSUs).
• Certifies products with more than 80% energy efficiency at 20%, 50%, and 100% of rated load.

Motherboard

• The main printed circuit board.
• Contains buses (electrical pathways) for data transfer among components.
• Also called the system board or main board.
• Houses the CPU, RAM, expansion slots, heat sink/fan assembly, chipset, sockets, BIOS, internal and external connectors, and various ports.
• All devices communicate with the CPU on the motherboard via cables.
• Input/Output (I/O) ports connected to peripherals like keyboards, mice, parallel ports, USB ports, and sound ports.

Motherboard Chipset

• Most chipsets consist of two types:
  • Northbridge: Controls high-speed access to RAM and the video card.
  • Southbridge: Allows the CPU to communicate with slower devices (hard drives, USB ports, and expansion slots).

Central Processing Unit (CPU)

• The amount of data a CPU processes depends on the size of the Front Side Bus (FSB), measured in bits.
• Overclocking: A technique to make a processor run faster than its original specification, not recommended as it can damage the CPU.
• CPU Throttling: The opposite of overclocking, where a processor runs below its rated speed to conserve power or reduce heat.
• CPU Virtualization: A hardware feature (supported by AMD and Intel CPUs) that allows a single processor to act as multiple processors. This allows multiple operating systems to run simultaneously on virtual machines.

Cache Memory

• A smaller, faster memory closer to the processor core that stores copies of data frequently used from main memory.
• Divided into three levels:
  • Level 1 (L1) cache: Fastest; holds data the CPU is most likely to need for a given task.
  • Level 2 (L2) cache: Slower than L1 but larger (256KB to 8MB); holds data the CPU is likely to need next.
  • Level 3 (L3) cache: Slower than L2 but still faster than main memory (RAM); feeds information to L2 and then to L1.

Types of Memory (ROM)

• Read-Only Memory (ROM): Information written during manufacturing; obsolete.
• Programmable Read-Only Memory (PROM): Information written after manufacturing, programmable only once.
• Erasable Programmable Read-Only Memory (EPROM): Non-volatile, erasable with UV light; can be reprogrammed.
• Electrically Erasable Programmable Read-Only Memory (EEPROM): Non-volatile; can be erased and reprogrammed electrically (also known as Flash ROM), often used to store BIOS.

Random Access Memory (RAM)

• Temporary working storage for data and programs being accessed by the CPU. RAM is volatile memory.
• More RAM generally enhances system performance as it provides more capacity to hold and process large programs and files.
• The maximum amount of RAM installable is limited by the motherboard.

Types of RAM

(Different types of RAM are detailed, but listing all is extensive. Provide a specific request if you need a particular type of RAM details.)

Adapter Cards and Expansion Slots

• Adapter cards enhance computer functionality by adding controllers for devices or replacing malfunctioning ports. Examples include sound, network, wireless network, video, and capture cards.

Types of Storage Devices

• Data storage devices store data non-volatiley, retaining data even when power is lost.
• They can be magnetic (HDD, tape drives), solid state, or optical (CD, DVD, BD).

Optical Storage Devices

• Optical media (CD, DVD, BD) can be pre-recorded (read-only), recordable (write-once), or re-recordable (read and write). Dual-layer media roughly doubles the capacity of a single-layer disc. (Detailed descriptions of various CD,DVD, BD formats are provided).

Occupational Safety and Health Framework

• Guiding principles of the new framework include:
  • Reducing risks at the source.
  • Instilling greater ownership of safety and health.
  • Preventing accidents through penalties.

Safety Sign Codes

• Red: Prohibition
• Yellow: Caution
• Green: Positive action
• Blue: Mandatory actions
• Discs: Prohibitions and instructions
• Triangles: Warnings
• Squares/Rectangles: Emergency and information signs

Risk Management Steps

• Identify: recognize hazards
• Assess & Analyze: evaluate the risks.
• Plan Action: develop strategies to mitigate the risks.
• Monitor & Implement: put mitigation plan into action.
• Measure & Control: assess the effectiveness of mitigation strategies.

Types of Hazards

• Physical and Mechanical: environmental factors harming the body w/o touching it.
• Chemical: exposure to workplace chemicals (solid, liquid, gas).
• Biological: associated with animals, people, or infectious plant materials.
• Ergonomic: work, body positions, work conditions causing strain on body.
• Electrical: improper handling of electrical equipment.

Risk Levels and Risk Control

• Low risk: existing precautions are likely to be adequate; no further need.
• Medium/High risk: more steps may be necessary for hazard mitigation.

Types of Risk Control

• Elimination: removing the hazard.
• Substitution: replacing a hazard with non-hazard alternative.
• Engineering controls: isolating people from the hazards.
• Administrative controls: changes in ways people work, including procedure changes, employee training, and signs/warnings.
• Personal Protective Equipment (PPE): measures such as gloves, respirators, hard hats, safety glasses, high-visibility clothing, and safety footwear to protect from hazards.

Safety Handling of Computer

• Electrostatic Discharge (ESD) is the buildup of an electric charge on a surface.
• ESD Protection:
  • Antistatic bags to store components.
  • Grounded mats/floors in work areas.
  • Antistatic wrist straps.

BIOS and UEFI Settings

• All motherboards require BIOS to operate.
• BIOS is ROM chip with program controlling communication between the OS and hardware.
• BIOS identifies available and bootable drives, memory configuration, PCle/PCI expansion slots, SATA/USB configurations, and motherboard power management features.
• UEFI is a newer standard that improves security and supports 32/64-bit systems for larger drives. (detailed information about secure boot)

Various Peripheral Devices

• Input devices allow user communication with the computer. Examples include:
  • Keyboard and Mouse
  • ADF/Flatbed Scanner
  • Joystick and Gamepad
  • KVM Switch
  • Touch Screen
  • Stylus
  • Magnetic Strip Reader
  • Barcode Scanner
  • Digital Camera
  • Webcam
  • Signature Pad
  • Smart Card Reader
  • Microphone
  • NFC devices / terminals
  • Facial recognition scanners
  • Fingerprint scanners
  • Voice recognition scanners
  • Virtual Reality Headsets

Monitor Characteristics

• Computer monitors are varied by use, size, quality, clarity, brightness.
• Screen size: diagonal measurement in inches.
• Resolution: number of horizontal and vertical pixels (e.g., 1920 x 1080).
• Monitor resolution: amount of information displayable.
• Native resolution: best monitor resolution.

External Peripheral Device Interfaces

• DVI: Supports uncompressed digital video (DVI-A analog, DVI-D digital, DVI-I integrated).
• HDMI: Carries digital video and audio signals.
• DisplayPort: Replaces DVI and VGA, providing high-bandwidth video and audio.
• Thunderbolt: High-speed connection for peripherals, including transmitting high-definition video.
• RCA: Audio/video connectors (yellow for video, red/white for audio).

Printer Technologies and Interfaces (Inkjet, Thermal, Impact)

Hardware Compatibility Requirements

• Refers to the compatibility of computer hardware with components like the CPU architecture, bus, motherboard, and operating system.
• Backward compatibility is the usability of newer versions of a technical object with an older version.
• Forward compatibility is the usability of older versions on a newer version.

Process of Upgrading Computer Devices (Motherboard, CPU, RAM, Storage, Graphic Card, Replacing Laptop Components)

Error Codes and Startup Messages (POST Errors)

Troubleshooting Process (Step 1 - Identify the Problem)

Common Problems and Solutions (PC Troubleshooting)

Key Activities of the First Level IT Help Desk:

Techniques for Effective Communication in Delivering Customer Service (Know, Relate, Understand, Active Listening, Professional Behavior with the Customer, Helping a Talkative Customer, Helping a Rude Customer, Helping a Knowledgeable Customer, Helping an Angry Customer, Helping an Inexperienced Customer)