5.2: Troubleshooting Common Hardware Problems

POST (Power-On Self-Test)

Test run before the OS boots to verify hardware like CPU, memory, and video.

Beep codes

Audible signals indicating POST failures; refer to motherboard documentation.

Blank screen on boot

May indicate bad video card, memory, CPU, or BIOS misconfiguration.

BIOS time/settings loss

Usually caused by a dead CMOS battery.

Incorrect boot device

System tries to boot from non-bootable device; check boot order and media.

Blue Screen of Death (BSOD)

Windows crash screen indicating critical failure.

Event Viewer

Windows tool to investigate crash or system issues.

Startup BSOD

Blue screen occurring during startup; often caused by bad drivers or hardware.

Last known good

Windows boot option that loads the last stable configuration.

System restore

Tool to revert Windows settings to a previous point.

Safe mode

Boot mode with minimal drivers for troubleshooting.

Reseat hardware

Removing and reinserting components to ensure proper connection.

Hardware diagnostics

Tools to test RAM, CPU, or hard drive health.

Spinning Ball of Death

macOS wait cursor indicating unresponsive application or system.

Console logs

macOS logs that can provide crash info or system messages.

Black screen

Can be due to no power, bad video signal, or dimmed display.

Check cables

Ensure monitor and video cables are properly connected.

Input selection

Verify monitor is on correct input (e.g., HDMI, VGA).

No power

Indicates failure in power supply or outlet; check with multimeter.

Fans spin but no POST

Could be motherboard or CPU issue.

Low voltage fans

Case fans may spin even with insufficient power to motherboard.

Sluggish performance

Caused by high CPU/memory use, updates, malware, or low disk space.

Defrag

Rearranging files on disk to improve performance (HDD only).

Power saving mode

Limits CPU performance on laptops to save energy.

Thermal throttling

CPU performance reduced due to heat.

Antivirus scan impact

High CPU usage from background malware scans.

Overheating

Caused by dust, blocked fans, or failing heatsinks.

Cleaning fans

Helps prevent overheating; ensure airflow is clear.

Temperature monitoring

Use BIOS or third-party tools to check CPU/GPU temps.

Smoke or smell

Indicates electrical damage—disconnect power immediately.

Intermittent shutdowns

Could be overheating, power issues, or hardware failure.

Application crash

Software stops working; check logs and event viewer.

Reliability monitor

Windows tool that tracks application failures over time.

Grinding noise

Usually from failing hard drives or fans.

Clicking noise

Often points to fan or mechanical hard drive issues.

Popping sound

Can be a blown capacitor on the motherboard.

Lockup

System becomes unresponsive; may be caused by RAM, drivers, or overheating.

Continuous reboot

May be bad driver or power issue; use safe mode or remove hardware.

Disabling auto-restart

Allows viewing of crash error messages during boot loops.

Inaccurate date/time

Sign of failing CMOS battery on motherboard.

Resetting BIOS

Removing battery or using a jumper resets configuration.