Hardware: PC Components, Identification & Troubleshooting

Understanding the physical components inside a computer is foundational for any A+ candidate or early-career technician. The CompTIA A+ exam tests not only recognition of parts like CPUs, motherboards, RAM, and storage but also practical troubleshooting processes. This post walks through component roles, common failure symptoms, diagnostic steps, and safe handling procedures that you can use in the field.

Start with the CPU — the processor coordinates almost every operation. Modern CPUs have multiple cores and integrated features such as thermal throttling and hardware virtualization. When a system fails to POST (Power-On Self Test) or immediately reboots under load, consider the CPU and its cooling. Common checks: verify the CPU cooler is installed correctly, ensure thermal paste is applied, examine motherboard socket pins (or pads) for damage, and confirm BIOS/UEFI recognizes the CPU model. If a machine shows random lockups or thermal shutdowns, run a stress test with temperature monitoring to confirm thermal issues rather than software problems.

The motherboard is the system’s backbone. When diagnosing motherboard-related failures, identify the form factor (ATX, mATX, ITX), chipset family, and socket type. If you see beep codes or POST LED indicators, consult the motherboard manual for their meaning — these codes often shortcut hours of trial-and-error. When possible, breadboard the system (minimal components: CPU, one RAM stick, onboard video) to isolate a faulty peripheral or add-on card.

Memory issues present with blue screens, random crashes, or failure to boot. Use reseating, swapping slots, and running memory tests (e.g., MemTest86) to detect faulty modules. Make sure modules are installed in the correct slots to enable dual- or quad-channel operation where applicable, and verify RAM speed/timings match motherboard and CPU capabilities.

Storage devices come in several flavors: HDDs, SATA SSDs, and NVMe drives. Symptoms of failing storage include slow performance, corrupted files, or drives not detected in BIOS. First steps: check cable/power connections, confirm detection in BIOS/UEFI, and run SMART diagnostics. For troubleshooting performance, test whether the device is connected to the correct interface (e.g., NVMe in proper M.2 slot) and verify firmware updates from the vendor.

Graphics troubleshooting typically centers on display output issues, artifacting, or driver conflicts. Verify the card is seated, auxiliary power cables are connected, and test with onboard video if available. Driver rollback can be a fast remedy if a recent update causes instability.

Power supplies cause many intermittent issues: random reboots, no power, or undervoltage. If symptoms are inconsistent, either use a PSU tester or substitute a known-good unit. Always check voltages under load; some problems only appear when the system draws higher power.

Peripherals and connectors are often overlooked. Faulty USB devices, damaged cables, or misconfigured BIOS options (e.g., legacy vs. UEFI boot) can create symptoms that mimic deeper hardware faults. Inspect connectors for bent pins and test devices on alternate ports.

Safety is paramount. Use ESD straps or mats when handling components, power down and unplug systems before working inside, and be careful with delicate M.2 modules and bent motherboard pins. When replacing components, keep screws and hardware organized, and avoid over-torquing.

Finally, adopt a methodical approach: identify symptoms, duplicate the issue when possible, isolate the failing component, repair or replace, and then test thoroughly. Document steps and outcomes — that documentation speeds future diagnostics and supports CEU submissions when you describe hands-on work.