Objectives

  • Name the main parts inside a computer cabinet.
  • Match common ports to devices.
  • Distinguish input, output, and storage devices.

Theory: Inside a computer cabinet, I/O devices, I/O ports.

Tasks (45 minutes)

  1. Exterior (10 min). On a lab PC, list: power button, optical drive (if any), USB ports, headphone/mic jacks, HDMI or VGA, Ethernet.
  2. Cabinet (15 min, instructor-supervised). With the case open (or using a labeled photo if opening is not allowed), identify motherboard, CPU cooler, RAM sticks, storage drive (HDD or SSD), PSU, expansion slots.
  3. Classify (10 min). Fill a table of eight devices in the lab (keyboard, mouse, monitor, printer, speaker, webcam, USB flash, barcode scanner if available) as input, output, or both.
  4. Ports (10 min). Draw or photograph USB-A, USB-C, HDMI, Ethernet, and audio jacks. Write one sentence on what each connects.

Before You Start

  • Work in pairs; one person handles the hardware, the other records.
  • The instructor shuts down and unplugs the PC before any cabinet is opened. Never open a PC that is still connected to mains power.
  • Touch the bare metal of the cabinet frame before touching components, to discharge static electricity. Hold RAM and cards by their edges.
  • Bring your phone for photos (no flash on open boards if the instructor asks) and a pen for the classification table.

Step-by-Step Guide

  1. Front and back panels. Start at the front: power button, reset button (if any), front USB ports, audio jacks (green = headphone/line out, pink = microphone). Turn to the back: the rear I/O panel on the motherboard (USB, Ethernet, audio), the video outputs (on the motherboard and/or a separate graphics card lower down), and the PSU power socket and switch.

  2. Inside the cabinet. Use this table to recognise each part:

    Component How to recognise it What it does
    Motherboard The large main circuit board everything plugs into Connects CPU, memory, storage and ports
    CPU and cooler Under a fan or metal heatsink near the top of the board Executes instructions; the cooler removes heat
    RAM Thin sticks in long slots beside the CPU, with clips at each end Temporary working memory; cleared when power is off
    Storage (HDD/SSD) HDD: metal box in a drive bay. SSD: small 2.5” box, or an M.2 stick screwed to the board Permanent storage for the OS, software and files
    PSU Box (usually top or bottom rear) with a bundle of cables Converts mains AC to the DC voltages the parts need
    Expansion slots Long horizontal slots (PCIe), sometimes holding a graphics or network card Add capabilities such as graphics or Wi-Fi

  3. Classify the devices. A completed table should look like this (check your answers against it):

    Device Category Reason
    Keyboard Input Sends keystrokes to the computer
    Mouse Input Sends pointer movement and clicks
    Monitor Output Displays processed information (a touch monitor is both)
    Printer Output Produces hard copy (a printer-scanner is both)
    Speaker Output Produces sound
    Webcam Input Captures video
    USB flash drive Storage (read and write) Stores data; not strictly input or output
    Barcode scanner Input Reads product codes into the system
  4. Ports. For each port, write what plugs in and what it carries. Example: “HDMI connects the PC to a monitor or projector and carries both video and audio.” Do the same for USB-A, USB-C, Ethernet (RJ-45, network) and the 3.5 mm audio jack.

Check Your Work

Checkpoint How to verify
Cabinet parts All six parts are labelled on your sketch or photo
Classification Eight devices, each with a category and a one-line reason
Ports Five ports, each with a one-sentence description
Safety You can state the two safety steps taken before touching components

Common Errors and Fixes

Problem Fix
Calling the hard disk “memory” Memory (RAM) is temporary; storage (HDD/SSD) is permanent. Use the right word.
Confusing the PSU with a UPS The PSU is inside the cabinet. A UPS is a separate battery unit that keeps power on during a cut.
Labelling the CPU cooler as the CPU The CPU sits underneath the cooler; write “CPU (under cooler)”.
Mixing up the Ethernet and phone jacks Ethernet (RJ-45) is wider, with 8 contacts; the phone jack (RJ-11) is narrower.

Extension Task

For those who finish early: Look up the specifications of the lab PC (in Windows: Settings → System → About). Record the processor, installed RAM and system type, and say whether the PC suits (a) office work and (b) video editing, with one reason each.

Deliverable

One page: labeled sketch or photo of the cabinet plus the classification table.

Viva

  1. Why is RAM not the same as an SSD?
  2. What happens if you unplug the PSU while the PC is on?
  3. Name two ports that carry video.
  4. Is a touchscreen input, output, or both?
  5. What is the role of the motherboard?
  6. Why does a CPU need a cooler?
  7. Give one example of a device that is both input and output, and explain why.
  8. Why must you touch the metal frame before handling RAM?