Worth 28% of the CompTIA A+ (Core 1) (220-1201) exam. CertClue has 115 questions on this objective.
Objective 5.5 asks you to diagnose network faults from symptoms. The pattern that matters most is whether the problem is connectivity, name resolution, or performance, because each has a different first step.
Exam tip. Always test by IP address and by hostname. If IP works and the name does not, it is DNS. If neither works, it is connectivity. This single test resolves most network scenario questions.
Peripheral faults are usually power, driver or port related. USB questions frequently turn on the difference between a port that lacks power and a device that lacks a driver.
Exam tip. Substitution testing is the expected troubleshooting step for peripherals. Choose the answer that isolates whether the port or the device has failed before replacing anything.
Heat and power faults produce overlapping symptoms - shutdowns, instability, throttling - so the exam expects you to use timing and load to tell them apart.
Exam tip. Use timing to separate the two. Failures that correlate with elapsed run time are thermal; failures that correlate with a specific demanding component are power.
Several Core 1 scenarios hinge on protecting user data during a repair. The expected answer almost always prioritises preserving data over restoring service quickly.
Exam tip. When a question offers both a diagnostic step and a backup step for a failing drive with important data, back up first. This ordering is tested repeatedly.
Firmware misconfiguration explains a set of faults that look like hardware failure. Knowing which setting causes which symptom saves needless component replacement.
Exam tip. When a system stops booting immediately after firmware settings were altered, do not troubleshoot the drive. Restore the setting or clear CMOS to defaults.
Although the formal troubleshooting methodology is no longer a tested objective in the 220-1201 series, the exam still rewards structured thinking. Isolate variables one at a time and start with the cheapest, least invasive test.
Exam tip. When several answers would eventually find the fault, choose the least invasive and least expensive step. The exam consistently rewards checking a cable before replacing a board.
Objective 5.1 is symptom-driven: you are given a described fault and must name the likely cause. The highest-value skill is separating a power fault from a component fault from a thermal fault.
Exam tip. Symptoms that only appear under load point at power or cooling. Symptoms present from the moment of power-on point at a component that is not seated or has failed outright.
Objective 5.2 covers failing storage. Mechanical noises indicate imminent hard drive failure; SMART warnings give you time to act. With RAID, the priority is replacing a failed member before a second one goes.
Exam tip. When a question mentions a clicking drive containing unbacked-up data, the first step is always to image or back up the data, not to run diagnostics or replace hardware.
Objective 5.3 lists a long set of display symptoms. Most map to one of four causes: wrong input, a cable problem, a backlight or bulb, or the panel itself.
Exam tip. The torch test separates a dead backlight from a dead panel and is the expected diagnostic step whenever a screen is described as very dark rather than black.
Objective 5.4 covers mobile faults, several of which are safety matters. A swollen battery is the one symptom that overrides all other troubleshooting priorities.
Exam tip. Any question featuring a swollen or bulging battery has a safety answer. Never choose an option that involves continuing to use, charging, or puncturing the device.
Objective 5.6 pairs print defects with failed components. For laser printers each defect maps to a specific part of the imaging process, which makes these questions very predictable once learned.
Exam tip. If toner smudges when touched, the answer is always the fuser. If output is unreadable characters rather than a physical defect, the answer is always the driver.
A machine that does not start splits into three cases: no power at all, power but no display, and display but no operating system. Each has a distinct set of causes, so classify before you troubleshoot.
Exam tip. Classify the failure point before choosing an action. Answers that reinstall the operating system are wrong when the machine never reaches POST.
Wireless faults are usually about signal quality rather than configuration. Distance, obstruction, interference and channel selection explain most complaints of slow or dropping Wi-Fi.
Exam tip. If users near the access point are fine and distant users are not, the answer is coverage - add an access point or run a site survey. If everyone is slow at the same time, it is congestion or interference.
Free, with the answer and the reasoning. No account needed.
1. A technician notices that file operations on a workstation take far longer than they used to, and the drive shows 100 percent active time with very low throughput. What is the most likely explanation?
A drive pinned at full activity while delivering very little actual throughput indicates the storage subsystem is struggling, typically because of a failing or badly worn mechanical drive. Display cabling, desktop contents and input drivers have no bearing on storage throughput.
2. One member drive has failed in a RAID 5 array and the array is running in a degraded state. What is the most significant risk if the failed drive is not replaced promptly?
RAID 5 survives exactly one drive failure. While degraded there is no remaining parity protection, so a second failure destroys the array. RAID levels do not silently convert, partition tables are unaffected, and degraded arrays remain writable.
3. Two devices connected by a long Ethernet cable run experience intermittent data errors, and the technician suspects the run exceeds the standard's maximum supported distance. What is the most likely underlying issue?
Signal attenuation increases with cable length, and exceeding the standard's maximum distance (about 100 meters for UTP Ethernet) causes signal degradation and intermittent errors. DNS settings, gateway configuration, and firewall rules are logical/software issues that wouldn't cause this kind of physical-layer, distance-related symptom.
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