Computer Hardware
Computer Hardware tests the physical components of a computer: processor, memory, motherboard, storage, power supply, ports, printers, and basic fault diagnosis. Expect text-based component facts and one practical troubleshooting question.
Processor and memory
- The CPU has an ALU, control unit, and registers; clock speed is in GHz; cores process tasks; cache L1 is fastest, then L2, L3, then RAM.
- RAM is volatile and holds running programs; ROM is non-volatile firmware; virtual memory uses disk space when RAM is full.
- The motherboard connects components via buses; BIOS/UEFI starts hardware and hands over to the bootloader; the CMOS battery keeps clock and settings.
Storage, power, ports
- HDD uses magnetic platters; SSD uses flash memory, has no moving parts, and is faster; optical storage uses a laser.
- SMPS converts AC mains to DC voltages; a UPS gives backup power.
- Ports include USB, HDMI, VGA, RJ45 Ethernet, and audio jacks; PS/2 is legacy keyboard/mouse.
- Printers: impact dot matrix; non-impact inkjet and laser; laser uses toner and a drum.
Worked example
A desktop asks for date and time on every boot and beeps once. The repeated clock loss points to a failing CMOS battery on the motherboard, not the hard disk. A single beep usually means POST passed; repeated beep patterns indicate RAM, graphics, or keyboard faults depending on the BIOS vendor. Replace the coin cell, then reset date/time and check boot order. Reasoning: CMOS SRAM is volatile, so the battery preserves settings when power is off.
Traps
More RAM does not increase CPU clock speed; cache is faster than RAM; SSD is not a magnetic disk; ROM is non-volatile; a 64-bit OS can address more RAM than a 32-bit OS.