1. Central Processing Unit (CPU)

What is a CPU? The CPU is the brain of the computer. It executes instructions, performs calculations, and controls other hardware.

How to design/select a CPU

• Clock Speed: Measured in GHz, it indicates how many cycles the CPU can perform per second. Higher is generally faster.
• Cores: CPUs can have multiple cores (dual, quad, octa, etc.) allowing multiple tasks simultaneously.
• Cache: Small, fast memory on the CPU to speed up access to frequently used data.
• Compatibility: Ensure the CPU socket matches the motherboard socket type (e.g., LGA1151, AM4).

Common CPU Issues

• Overheating: Can cause shutdowns or throttling. Usually due to poor cooling or dried thermal paste.
• Failure to boot: Can result from incorrect CPU installation or damaged pins.
• Performance bottleneck: CPU is too slow for the tasks or software being used.

Troubleshooting & Fixes

• Check and apply new thermal paste when overheating occurs.
• Ensure CPU fan and heatsink are correctly installed and working.
• Verify correct CPU placement and no bent pins before powering on.
• Upgrade CPU if performance is inadequate for your needs.

2. Random Access Memory (RAM)

What is RAM? RAM is temporary memory used by the CPU to store data and instructions that are actively in use.

How to design/select RAM

• Capacity: Measured in GB, more RAM allows more applications to run smoothly.
• Speed: Measured in MHz, higher speeds allow faster data access.
• Type: DDR3, DDR4, DDR5 — newer types are faster and more efficient.
• Compatibility: Must match motherboard RAM slots and supported types.

Common RAM Issues

• System crashes or blue screen: Often caused by faulty RAM modules.
• Computer freezing or slow response: Insufficient RAM or bad RAM.
• Failure to boot with RAM error beep codes.

Troubleshooting & Fixes

• Use memory diagnostic tools (e.g., Windows Memory Diagnostic, MemTest86) to test RAM health.
• Remove and reseat RAM modules to ensure proper contact.
• Replace faulty RAM modules with compatible, good-quality sticks.
• Upgrade RAM if multitasking or heavy applications require more memory.

3. Hard Disk Drive (HDD) & Solid State Drive (SSD)

What is HDD/SSD? They are devices for permanent storage of your data, software, and operating system.

How to design/select HDD/SSD

• Capacity: Larger sizes (GB/TB) mean more storage space.
• Speed: HDD speed is measured in RPM (7200 RPM is faster). SSDs are much faster than HDDs due to no moving parts.
• Interface: SATA, NVMe (for SSDs), ensure compatibility with motherboard ports.
• Durability: SSDs are more durable and shock-resistant than HDDs.

Common HDD/SSD Issues

• Slow performance: Caused by fragmentation (HDD) or nearly full drive.
• Clicking noises or failure to detect (HDD): Mechanical failure.
• Bad sectors or corrupted files: Data loss or system errors.
• Drive not detected: Loose cables or drive failure.

Troubleshooting & Fixes

• Run disk checking utilities (chkdsk for Windows, fsck for Linux) to scan and fix bad sectors.
• Use disk defragmenter regularly for HDDs to improve performance.
• Backup important data frequently to avoid data loss.
• Replace faulty drives promptly to avoid total failure.
• For SSD, keep firmware updated and avoid unnecessary writes.

4. Motherboard

What is a Motherboard? The motherboard is the main circuit board connecting all computer components, allowing communication between CPU, RAM, storage, and peripherals.

How to design/select a Motherboard

• Form Factor: ATX, Micro-ATX, Mini-ITX — must fit in the computer case.
• Socket Type: Must match the CPU socket.
• RAM Slots: Number and type supported.
• Expansion Slots: PCIe slots for graphics cards, sound cards, etc.
• Connectivity: USB ports, SATA connectors, M.2 slots, Ethernet, audio jacks.

Common Motherboard Issues

• No power or boot: Faulty motherboard or power delivery issues.
• Random restarts or freezes: Short circuits, bad capacitors, or overheating.
• Hardware not detected: Bad slots or damaged traces.
• BIOS corruption: System fails to POST or boot.

Troubleshooting & Fixes

• Inspect visually for swollen or leaking capacitors.
• Reset CMOS to clear BIOS errors.
• Check all power connectors and cables are firmly connected.
• Test with minimal hardware (CPU, one RAM stick, no peripherals) to isolate problems.
• Update or reflash BIOS if corrupted.

Summary of Unique Skills to Master

• Using hardware monitoring tools (temperature, voltage, performance).
• Performing visual inspections for hardware damage.
• Understanding BIOS/UEFI settings and updates.
• Using diagnostic software for RAM and disk testing.
• Proper static handling (ESD protection) when working inside computers.
• Interpreting motherboard beep codes and error LEDs.
• Replacing thermal paste correctly and installing cooling solutions.
• Backup and recovery strategies for data safety.
• Identifying and matching compatible hardware components.