Introduction to Computer Repair and Maintenance
Study guide – key concepts, tools, procedures, and best practices
1. Why Maintenance Matters
| Reason |
What It Prevents |
Typical Impact |
| Reliability |
Hardware failures, data loss |
Downtime, lost productivity |
| Performance |
Slow boot, lagging applications |
User frustration, reduced efficiency |
| Security |
Malware, unpatched vulnerabilities |
Data breach, system compromise |
| Longevity |
Component wear, overheating |
Early replacement costs |
2. Core Components of a PC (Hardware Overview)
| Component |
Primary Function |
Common Failure Modes |
| CPU (Processor) |
Executes instructions |
Overheating, thermal paste degradation |
| RAM (Memory) |
Temporary data storage |
Faulty modules, bad contacts |
| Motherboard |
Connects all parts |
Capacitor bulging, BIOS corruption |
| Power Supply (PSU) |
Provides regulated power |
Voltage spikes, fan failure |
| Storage (HDD/SSD) |
Persists data |
Bad sectors, controller failure |
| Graphics Card (GPU) |
Renders video |
Overheating, driver issues |
| Cooling System (fans, heatsinks, liquid) |
Keeps temps in range |
Dust buildup, fan wear |
| Peripheral Interfaces (USB, Ethernet, audio) |
I/O connectivity |
Port damage, driver conflicts |
3. Safety First – Personal & Equipment
- Power Safety
- Unplug the unit or shut down the PSU switch before opening.
- Use a grounded anti‑static wrist strap (or touch a metal chassis) to discharge static.
- Tool Checklist
- Phillips & flathead screwdrivers (magnetic tips recommended)
- Precision tweezers, plastic spudger
- Cable ties / Velcro straps
- Multimeter (voltage/continuity)
- Thermal paste, cleaning alcohol (≥90%), lint‑free wipes
- External boot media (USB/DVD) for diagnostics
- Environmental Precautions
- Work on a clean, well‑lit surface.
- Keep liquids away from the workstation.
- Maintain moderate temperature (20‑25 °C) and low humidity.
4. Diagnostic Workflow (Step‑by‑Step)
-
Gather Information
- Ask the user for symptoms, recent changes, error messages.
- Document hardware specs (model numbers, serials).
-
Visual Inspection
- Look for swollen capacitors, burnt components, loose cables, dust accumulation.
-
Power‑On Self Test (POST) Observation
- Listen for beep codes (refer to motherboard manual).
- Note any POST error messages on screen.
-
Basic Tests
- Power – Verify PSU output with a multimeter or PSU tester.
- Memory – Run MemTest86 (bootable USB) for at least 2 passes.
- Storage – Use manufacturer’s diagnostic tool (e.g., Seagate SeaTools, Samsung Magician) or CHKDSK / SMART data.
- CPU / GPU – Stress test with Prime95, AIDA64, or FurMark while monitoring temps.
-
Software Diagnostics
- Boot into a clean environment (Windows Safe Mode, Linux Live USB).
- Check Device Manager for driver conflicts.
- Run sfc /scannow and DISM (Windows) for system file integrity.
-
Isolation
- Remove non‑essential components (