CompTIA A+ · Domain 5 · 28% of the examCore 1 (220-1201) · Hardware and Network Troubleshooting
10 practice questions. Tap an option to check it, or open “Show answer” for the explanation.
1. Every time a desktop is unplugged overnight, it boots the next morning with the date reset to 2010 and its firmware settings back to defaults. What should the technician replace?
Objective 5.1Show answerHide answer
Answer: B. CMOS battery
The CMOS battery keeps the real-time clock and firmware settings when the PC has no AC power. A failing power supply causes no-power or random-shutdown problems, not lost settings after unplugging.
Checked by Claude Opus 5.5 (high effort) · Oct 14, 2026
2. A workstation shuts off without warning during long video renders but runs fine when idle. The inside of the case is dusty and the CPU fan is loud. What is the most likely cause and fix?
Objective 5.1Show answerHide answer
Answer: C. CPU overheating; clean out the dust and reseat the cooler with fresh thermal paste
Shutting off only under heavy load, together with dust and a straining fan, points to thermal protection kicking in. A bad driver usually causes app crashes or a crash screen, not an instant power-off.
Checked by Claude Opus 5.5 (high effort) · Oct 14, 2026
3. A user's PC is making repeated clicking sounds, and a S.M.A.R.T. warning appears at startup. What should the technician do first?
Objective 5.2Show answerHide answer
Answer: D. Back up the user's data immediately and plan to replace the drive
Clicking together with a S.M.A.R.T. warning means a mechanical failure is coming, so getting the data off comes first. chkdsk /r reads the whole disk intensively, which can speed up the failure, and it can't fix a mechanical fault.
Checked by Claude Opus 5.5 (high effort) · Oct 14, 2026
4. A server's RAID 1 controller is beeping and reports the array as degraded, and one drive's status LED is amber. The data is still accessible. What should the technician do?
Objective 5.2Show answerHide answer
Answer: A. Replace the failed drive with a compatible one and let the array rebuild
RAID 1 survives one drive failure, so swapping the failed drive and rebuilding restores redundancy. Initializing a new array would erase the data that's still intact on the good drive.
Checked by Claude Opus 5.5 (high effort) · Oct 14, 2026
5. A laptop's screen is almost black, but shining a flashlight at it shows the desktop faintly. An external monitor works normally. What is the most likely cause?
Objective 5.3Show answerHide answer
Answer: B. The backlight has failed (or, on older CCFL panels, the inverter)
The image is still being drawn, so only the light source behind it has failed. A failed GPU would affect the external monitor too.
Checked by Claude Opus 5.5 (high effort) · Oct 14, 2026
6. A conference room projector turns itself off after about 20 minutes, then works again once it has cooled down. What should be checked first?
Objective 5.3Show answerHide answer
Answer: A. A clogged air filter or blocked vents causing overheating
Shutting down after running a while and recovering once cool is a sign of thermal protection, often from a dirty filter or failing fan. A loose cable would cause lost signal, not the projector powering itself off.
Checked by Claude Opus 5.5 (high effort) · Oct 14, 2026
7. A user's phone screen is lifting away from the frame and the back is bulging. What should the technician do?
Objective 5.4Show answerHide answer
Answer: D. Power the phone off, stop charging it, and have the swollen battery replaced and recycled properly
A swollen lithium-ion battery is a fire hazard and has to be replaced and disposed of correctly. Recalibration only affects how charge level is reported and does nothing about physical swelling.
Checked by Claude Opus 5.5 (high effort) · Oct 14, 2026
8. Users in a break room say their laptops drop Wi-Fi whenever the microwave is running. The access point there is dual-band but is set to serve clients only on 2.4 GHz. What is the best fix?
Objective 5.5Show answerHide answer
Answer: C. Move the clients to the 5 GHz band
Microwave ovens give off energy in the 2.4 GHz band and interfere with Wi-Fi there, so 5 GHz avoids the problem. The DHCP lease time controls addressing and has no effect on radio interference.
Checked by Claude Opus 5.5 (high effort) · Oct 14, 2026
9. VoIP calls in an office sound choppy and robotic whenever large file backups run, even though tests show enough average bandwidth. What is the likely problem and fix?
Objective 5.5Show answerHide answer
Answer: B. Jitter from congestion; configure QoS to prioritize voice traffic
Uneven packet delay (jitter) during congestion breaks real-time audio, and QoS gives voice traffic priority over bulk transfers. Port flapping would drop all traffic on the link at random, not only while backups run.
Checked by Claude Opus 5.5 (high effort) · Oct 14, 2026
10. A laser printer prints a faint copy of the page's image further down each sheet. What is the most likely cause?
Objective 5.6Show answerHide answer
Answer: D. A worn imaging drum
Ghost (echo) images come from a drum that isn't being fully cleaned and discharged between rotations. Low toner causes faded prints, not repeated images.
Checked by Claude Opus 5.5 (high effort) · Oct 14, 2026
Original practice questions written from CompTIA’s published exam objectives, not real exam questions. CompTIA is a trademark of CompTIA, Inc.; this site isn’t affiliated with CompTIA.