CompTIA 220-1201 CompTIA A+ Certification Exam: Core 1 Exam Dumps and Practice Test Questions Set 5 Q61-75
Visit here for our full CompTIA 220-1201 exam dumps and practice test questions.
Question61
A user reports that their laptop overheats during light usage, causing the system to throttle performance and occasionally shut down. The technician observes dust buildup around the cooling vents. Which of the following is the MOST likely cause?
A) Overheating due to clogged vents
B) Outdated operating system
C) Incorrect network configuration
D) Faulty USB ports
Answer: A
Explanation:
When a laptop overheats even during light usage, the primary consideration is the cooling system. Option A, overheating due to clogged vents, is the most probable cause. Dust and debris accumulation obstruct airflow, preventing fans from effectively dissipating heat generated by the CPU, GPU, and other internal components. CompTIA 220-1201 emphasizes diagnosing thermal issues as a common cause of unexpected shutdowns and performance throttling. Overheating triggers built-in thermal protection mechanisms, including throttling CPU performance or initiating system shutdowns to prevent permanent hardware damage. Cleaning dust from vents, fans, and heat sinks restores proper airflow and thermal management, resolving overheating problems efficiently.
Option B, an outdated operating system, may cause some software inefficiencies but rarely triggers thermal throttling or sudden shutdowns during light workloads. Software alone cannot generate sufficient heat to overwhelm the cooling system.
Option C, incorrect network configuration, affects connectivity but has no influence on the device’s internal temperature. Network misconfigurations are unrelated to thermal behavior.
Option D, faulty USB ports, impact peripheral connectivity but do not affect heat generation or airflow. The correct solution focuses on cleaning and maintaining the cooling system, ensuring proper fan operation, and monitoring internal temperatures to prevent further overheating.
Question62
A user reports that their wireless laptop disconnects intermittently from the corporate network, while other devices maintain stable connections. The wireless driver is up to date. Which of the following is the MOST likely cause?
A) Wireless adapter power management settings
B) Incorrect Ethernet cable
C) Faulty monitor
D) Outdated printer drivers
Answer: A
Explanation:
Intermittent wireless connectivity on a single laptop indicates a client-specific issue. Option A, wireless adapter power management settings, is the most likely cause. Laptops often employ power-saving modes that reduce power to the wireless adapter to extend battery life. These settings can temporarily disable the adapter or reduce transmission power, causing periodic disconnects, especially during high network load. CompTIA 220-1201 highlights the importance of evaluating power management configurations in troubleshooting mobile device network issues. By disabling aggressive power-saving features for the adapter, the technician ensures full operational capacity, maintaining consistent connectivity.
Option B, incorrect Ethernet cable, is irrelevant because the issue involves Wi-Fi connectivity, not wired connections.
Option C, a faulty monitor, affects display functionality but does not impact wireless communication.
Option D, outdated printer drivers, influence printing tasks but do not interfere with network connections. Adjusting power management settings resolves the connectivity problem efficiently.
Question63
A desktop PC is transferring files to an external USB hard drive much slower than expected. The same drive operates at normal speed on other systems. Internal drives perform well. Which of the following is the MOST likely cause?
A) USB port operating at a lower speed
B) Fragmented internal hard drive
C) Outdated display driver
D) Insufficient RAM
Answer: A
Explanation:
External drive performance is dictated by the interface speed. Option A, the USB port operating at a lower speed, is the most probable cause. Many desktops include a mix of USB 2.0 and USB 3.x ports. Connecting a high-speed USB 3.x device to a USB 2.0 port drastically reduces data transfer rates. CompTIA 220-1201 stresses understanding interface limitations and ensuring devices connect to ports that support their maximum speed. Testing the drive in other ports, confirming controller drivers are updated, and ensuring compatibility with the USB standard typically resolves slow transfer issues.
Option B, fragmented internal hard drive, affects internal disk operations but does not influence external device performance.
Option C, outdated display drivers, impact graphics rendering but do not affect data transfer rates.
Option D, insufficient RAM, could marginally affect buffering but would not account for substantial slowdowns in modern systems. Connecting the external drive to the correct high-speed USB port resolves the issue efficiently.
Question64
A laptop battery shows “not charging” when connected to an AC adapter, although the adapter LED is on and the device powers on. Which of the following is the MOST likely cause?
A) Battery health issue or calibration required
B) Faulty Ethernet cable
C) Monitor brightness set too high
D) Outdated keyboard driver
Answer: A
Explanation:
When a laptop indicates “not charging” despite a functional AC adapter, the issue typically relates to the battery itself. Option A, a battery health issue or the need for calibration, is the most probable cause. Lithium-ion batteries degrade over time, losing capacity to accept or retain charge. Improper calibration can cause the operating system to misreport the battery status, preventing charging. CompTIA 220-1201 emphasizes diagnosing mobile device power problems by checking battery health, performing recalibration, and replacing the battery if necessary. Once assessed and addressed, normal charging resumes.
Option B, a faulty Ethernet cable, is irrelevant; networking hardware does not affect battery charging.
Option C, monitor brightness, slightly increases power consumption but does not prevent the battery from charging when connected to AC power.
Option D, outdated keyboard drivers, affect input functionality and do not influence battery operation. Addressing battery health or performing calibration restores charging capability.
Question65
A desktop PC fails to boot. The power LED is on, fans spin, but the monitor remains blank, and no beep codes are heard. Which of the following is the MOST likely cause?
A) Power supply failure
B) Faulty GPU
C) Incorrect display resolution
D) Loose keyboard connection
Answer: A
Explanation:
When a desktop powers on (fans spinning, LEDs active) but fails to display anything, power distribution issues are often the root cause. Option A, power supply failure, is the most likely explanation. A malfunctioning PSU may provide enough voltage to run fans and LEDs, but insufficient or unstable power to the motherboard, CPU, and GPU prevents successful POST (Power-On Self-Test). CompTIA 220-1201 objectives emphasize interpreting system indicators to identify hardware faults. Using a power supply tester or multimeter can confirm insufficient output. Once verified, replacing the PSU restores proper system function.
Option B, a faulty GPU, could prevent display output but would not stop the motherboard and CPU from initializing completely. Many motherboards have onboard graphics that default if a dedicated GPU fails, allowing POST and beep codes to occur.
Option C, incorrect display resolution, affects OS-level output, not initial boot or POST.
Option D, a loose keyboard, may trigger minor BIOS errors but would not prevent system POST or display output entirely. Therefore, verifying the PSU is the first step to restore boot functionality.
Question66
A user reports that their laptop screen flickers intermittently when moving the lid or adjusting the display angle. The display driver is up to date. Which of the following is the MOST likely cause?
A) Faulty display cable or hinge connection
B) Outdated operating system
C) Incorrect network configuration
D) Low battery power
Answer: A
Explanation:
When a laptop exhibits flickering that coincides with physical movement of the lid, the issue is almost always hardware-related rather than software-related. Option A, a faulty display cable or hinge connection, is the most likely cause. Modern laptops rely on flexible ribbon cables running from the motherboard to the display panel to transmit video signals. These cables are routed through the hinge mechanism to allow the screen to open and close. Over time, repeated motion, friction, or strain can cause the cable to fray, develop micro-cracks, or lose its connection intermittently, resulting in screen flickering or blanking. CompTIA 220-1201 objectives emphasize the need to distinguish hardware failures from software or driver issues when troubleshooting display anomalies. Although the display driver is up to date, the presence of flickering triggered specifically by lid movement indicates a mechanical issue rather than a driver conflict or operating system problem.
Option B, an outdated operating system, could theoretically cause software-based flickering in scenarios where driver support is misaligned with OS updates, but this does not explain flickering that is directly linked to physical movement. The system’s behavior correlates with motion, not software activity, making this less probable.
Option C, incorrect network configuration, has no relationship to video signal integrity or display behavior. Network misconfigurations affect connectivity and data flow but do not cause hardware-driven visual issues.
Option D, low battery power, might trigger automatic dimming or power-saving screen adjustments but would not cause flickering specifically when the lid is moved. While low battery can indirectly affect brightness and performance in some power-saving modes, it does not impact the physical video cable or hinge mechanism.
The correct troubleshooting process involves opening the laptop and inspecting the hinge and display cable for wear, damage, or loose connections. Repairing or replacing the ribbon cable and reinforcing the hinge connection resolves intermittent flickering. Preventive maintenance, including careful lid movement and periodic inspection of flexible internal cables, prolongs the lifespan of the display system and ensures stable visual performance. Understanding the mechanical design of laptops and their signal pathways is critical for accurate diagnosis.
Question67
A desktop PC fails to boot. Fans spin, LEDs are on, but no display appears and no beep codes are present. Which of the following is the MOST likely cause?
A) Power supply failure
B) Faulty GPU
C) Incorrect display resolution
D) Loose keyboard connection
Answer: A
Explanation:
A desktop system that powers on partially—fans spinning, LEDs illuminating—but fails to display POST (Power-On Self-Test) output is indicative of insufficient or unstable power delivery. Option A, power supply failure, is the most likely cause. The PSU provides regulated power to all components, including the motherboard, CPU, memory, and peripheral devices. Even if the PSU can power fans and LEDs, it may fail to supply adequate voltage to the CPU or memory, preventing POST completion. CompTIA 220-1201 emphasizes interpreting system behavior and using diagnostic tools to identify power-related issues. Symptoms like no display output, absence of beep codes, and partial power-on strongly suggest the PSU is the root cause.
Option B, a faulty GPU, could prevent video output. However, most modern motherboards have integrated graphics that should allow POST to occur, often generating beep codes if the GPU is defective. The absence of beep codes indicates that critical system initialization is not occurring, pointing to power delivery issues rather than GPU failure.
Option C, incorrect display resolution, affects output only after the operating system loads, and would not prevent BIOS initialization or POST from running. The system would still display initial boot information or BIOS screens, which is not happening here.
Option D, a loose keyboard connection, may cause minor BIOS warnings or error beeps but cannot prevent the system from initializing or displaying output entirely. The first step in troubleshooting involves testing the PSU with a known working unit or using a multimeter to verify voltage output. Once the PSU is confirmed faulty, replacement restores full system boot capability. Recognizing the difference between partial power-on due to PSU failure and component-specific failures is essential in accurate diagnosis and efficient resolution.
Question68
A laptop battery shows “not charging” while the AC adapter LED is on and the laptop powers on. Which of the following is the MOST likely cause?
A) Battery health issue or calibration needed
B) Faulty Ethernet cable
C) Monitor brightness set too high
D) Outdated keyboard driver
Answer: A
Explanation:
When a laptop indicates “not charging” despite the AC adapter being connected and functional, the battery is the primary suspect. Option A, a battery health issue or the need for calibration, is the most probable cause. Lithium-ion batteries degrade over time, resulting in reduced capacity and the inability to accept or hold charge effectively. Additionally, battery miscalibration can cause the system to report incorrect battery status, preventing charging even if the power supply is functioning correctly. CompTIA 220-1201 highlights troubleshooting power issues by assessing battery health, performing recalibration, and replacing degraded batteries as needed.
Option B, a faulty Ethernet cable, does not impact power delivery or charging, making it irrelevant in this scenario.
Option C, monitor brightness set high, slightly increases power draw but does not prevent charging from a functioning AC adapter. High brightness only affects battery life duration, not the ability to charge.
Option D, outdated keyboard drivers, affect input but not battery operation or charging.
Diagnosing involves checking battery health via system diagnostics or third-party tools, performing recalibration cycles to restore accurate battery reporting, and replacing the battery if it cannot hold a charge. Understanding battery chemistry, voltage thresholds, and system power management behavior is crucial for accurately identifying this type of problem. Once addressed, the laptop resumes normal charging functionality and reliable battery performance.
Question69
A user reports that their wireless laptop intermittently disconnects while other devices maintain stable connections. The wireless driver is up to date. Which of the following is the MOST likely cause?
A) Wireless adapter power management settings
B) Incorrect Ethernet cable
C) Faulty monitor
D) Outdated printer drivers
Answer: A
Explanation:
Intermittent wireless connectivity on a single device, while other devices on the same network remain stable, is typically a client-side configuration issue. Option A, wireless adapter power management settings, is the most likely cause. Laptops often use power-saving features that reduce energy supplied to the wireless adapter to conserve battery life. These settings can temporarily disable or throttle the adapter, leading to frequent disconnections, particularly under high network load or during prolonged activity. CompTIA 220-1201 objectives include evaluating client device configurations as part of network troubleshooting. Adjusting power management to ensure full operational power to the adapter often resolves connectivity issues, allowing uninterrupted communication with the network.
Option B, an incorrect Ethernet cable, is irrelevant for Wi-Fi connectivity and cannot cause wireless disconnections.
Option C, a faulty monitor, affects display and has no impact on network operations.
Option D, outdated printer drivers, may affect printing tasks but do not interfere with wireless connectivity. Diagnosing client-specific power management settings and correcting them is the proper course of action for restoring stable wireless performance.
Question70
A desktop PC transfers files to an external USB drive much slower than expected, while the same drive operates normally on other computers. Internal drives perform at normal speeds. Which of the following is the MOST likely cause?
A) USB port operating at a lower speed
B) Fragmented internal hard drive
C) Outdated display driver
D) Insufficient RAM
Answer: A
Explanation:
Slow performance of an external USB drive on a single system, while the drive functions normally elsewhere, points to the interface as the limiting factor. Option A, the USB port operating at a lower speed, is the most likely cause. Many desktop systems include both USB 2.0 and USB 3.x ports. Connecting a high-speed drive to a USB 2.0 port throttles transfer rates due to the port’s lower bandwidth limitations. CompTIA 220-1201 highlights troubleshooting peripheral performance by evaluating interface compatibility and ensuring optimal connection. Testing the drive on other ports, confirming that USB controller drivers are updated, and ensuring compliance with the correct standard typically resolves slow transfer issues.
Option B, a fragmented internal hard drive, impacts only internal storage operations and does not affect external drive performance.
Option C, outdated display drivers, affect graphical output but do not influence USB transfer speeds.
Option D, insufficient RAM may minimally affect buffering but is unlikely to be the root cause given modern system memory sizes and the fact that internal drives perform normally. Proper troubleshooting involves identifying the USB standard of the port, relocating the drive to a compatible port, and confirming driver functionality to restore expected transfer performance.
Question71
A user reports that their laptop battery drains rapidly even when the system is idle. The laptop is running the latest operating system updates and drivers. Which of the following is the MOST likely cause?
A) Background applications consuming excessive resources
B) Outdated display driver
C) Incorrect Ethernet cable
D) Faulty monitor
Answer: A
Explanation:
Rapid battery drain, especially when a laptop is idle, is often caused by software rather than hardware failures. Option A, background applications consuming excessive resources, is the most likely cause. Modern operating systems can run numerous background processes, including update services, cloud synchronization, antivirus scans, and telemetry services. CompTIA 220-1201 emphasizes understanding system performance metrics and energy consumption patterns for mobile devices. These processes may continue running even when the laptop appears idle, resulting in elevated CPU and memory usage and causing the battery to drain faster than expected.
By using built-in performance monitoring tools, such as Task Manager on Windows, a technician can identify which applications or services are consuming significant CPU or disk activity. Mobile devices may also use scheduled background tasks for syncing cloud services, indexing files, or updating applications, all of which contribute to energy consumption. Identifying and managing these processes through configuration adjustments, disabling unnecessary startup applications, or scheduling intensive tasks for periods when the device is connected to AC power can significantly improve battery life.
Option B, an outdated display driver, affects graphics performance and may contribute to minor power inefficiencies, particularly on laptops with integrated graphics that throttle power management poorly, but it is unlikely to be the primary cause of rapid battery drain when idle.
Option C, an incorrect Ethernet cable, affects network connectivity but has no impact on battery usage. Wired connections do not draw additional significant power in idle mode.
Option D, a faulty monitor, could theoretically increase power consumption if brightness or backlighting fails to regulate properly, but laptops regulate display power through internal controls. Hardware faults in the monitor alone would not explain significant idle power loss.
To resolve the issue, a technician should audit running background processes, examine scheduled tasks, and review power management settings to ensure the device efficiently balances energy consumption. Managing background application behavior, combined with adjusting screen brightness, enabling sleep modes, and updating firmware for energy management features, restores expected battery performance. Proper understanding of system resource allocation and power usage monitoring is critical in identifying these types of issues and optimizing laptop longevity.
Question72
A desktop PC intermittently freezes while running multiple applications. Task Manager shows high memory usage, but CPU utilization is moderate. Which of the following is the MOST likely cause?
A) Insufficient RAM
B) Outdated graphics driver
C) Incorrect display resolution
D) Loose keyboard connection
Answer: A
Explanation:
Intermittent system freezing with high memory usage and moderate CPU load strongly indicates insufficient RAM as the root cause. Option A, insufficient RAM, is the most likely explanation. RAM serves as the primary storage for active processes, applications, and data that the CPU requires for rapid access. When physical memory is exhausted, the operating system relies on virtual memory stored on the disk, which is significantly slower and can lead to system freezes or noticeable lag. CompTIA 220-1201 objectives highlight the importance of assessing system resource utilization and identifying hardware limitations.
The technician can verify RAM utilization using built-in performance tools, such as Task Manager, Resource Monitor, or third-party diagnostic software. If memory usage is consistently at or near maximum capacity, adding physical memory or reducing the number of simultaneously running applications resolves the issue. Virtual memory settings should also be reviewed to ensure sufficient pagefile allocation, but physical RAM is the most effective solution for high-demand multitasking environments.
Option B, outdated graphics drivers, may cause graphical artifacts, stuttering, or slow rendering of visual content, but it does not typically lead to system-wide freezing when CPU load is moderate. The problem described is resource exhaustion at the memory level rather than graphical output issues.
Option C, incorrect display resolution, affects visual clarity and screen layout but does not impact RAM allocation or system stability.
Option D, a loose keyboard connection, could cause sporadic input errors but does not affect system memory usage or freezing behavior across multiple applications.
Effective resolution involves auditing running processes, identifying memory-intensive applications, upgrading physical RAM, and ensuring efficient virtual memory configuration. CompTIA 220-1201 emphasizes that understanding the interaction between hardware capacity and workload is critical for diagnosing performance bottlenecks and ensuring stable operation in desktop computing environments. This approach ensures that both software and hardware considerations are evaluated comprehensively to restore system stability.
Question73
A user reports that an external USB drive is recognized by their desktop system but transfers files significantly slower than expected. The same drive performs normally on other computers. Which of the following is the MOST likely cause?
A) USB port operating at a lower speed
B) Fragmented internal hard drive
C) Outdated display driver
D) Insufficient RAM
Answer: A
Explanation:
When an external USB device functions on one system but exhibits poor performance, the most common cause is the interface rather than the device itself. Option A, USB port operating at a lower speed, is the most probable explanation. Many desktops have a mix of USB 2.0 and USB 3.x ports. Connecting a USB 3.x high-speed drive to a USB 2.0 port reduces maximum transfer rates from gigabit speeds to around 480 Mbps, resulting in significant delays during large file transfers. CompTIA 220-1201 objectives emphasize evaluating peripheral connection standards and optimizing hardware compatibility for performance troubleshooting.
Technicians can identify port types by examining motherboard documentation, color-coding of ports (often blue for USB 3.x), or using system information tools. Ensuring proper driver installation for the USB controller is also critical, as outdated or misconfigured drivers can further limit throughput. Testing the drive in a known high-speed port and observing the transfer rates confirms the diagnosis.
Option B, fragmented internal drives, affects only internal read/write operations and does not influence external device transfer speeds.
Option C, outdated display drivers, impact graphical output and rendering but do not affect USB throughput.
Option D, insufficient RAM, may slightly affect buffering during transfers but would not account for significant slowdowns when internal drives operate normally.
Resolution involves relocating the external drive to a compatible high-speed port, confirming USB controller driver updates, and ensuring proper system configuration. Understanding interface limitations and compatibility ensures maximum performance, aligning with CompTIA 220-1201 troubleshooting standards. This approach prevents unnecessary component replacement and provides a clear method for optimizing data transfer performance across external devices.
Question74
A laptop fails to connect to a corporate Wi-Fi network, while other devices on the same network connect successfully. The wireless adapter is functioning and the driver is up to date. Which of the following is the MOST likely cause?
A) Wireless adapter power management settings
B) Faulty Ethernet cable
C) Outdated monitor driver
D) Incorrect keyboard layout
Answer: A
Explanation:
When a single device experiences intermittent or complete wireless connectivity failure while other devices remain unaffected, the issue is generally client-side. Option A, wireless adapter power management settings, is the most likely cause. Laptops often implement power-saving measures that reduce or temporarily disable the wireless adapter to conserve battery life. Aggressive power management can prevent consistent communication with access points, resulting in connection drops or inability to join networks. CompTIA 220-1201 emphasizes evaluating client configuration settings, particularly for mobile devices, as part of network troubleshooting protocols.
Adjusting wireless adapter settings in the operating system to disable power-saving features ensures the adapter maintains full operational capacity. Additionally, reviewing advanced adapter settings, updating firmware, and verifying adapter priority settings in network profiles helps maintain stable connectivity. Power management conflicts often occur after OS updates, driver updates, or changes to battery profiles, making this a frequent source of client-specific connectivity issues.
Option B, a faulty Ethernet cable, is irrelevant for Wi-Fi connectivity and does not influence the wireless adapter’s ability to join or maintain connections.
Option C, outdated monitor driver, impacts visual output but has no effect on networking hardware.
Option D, incorrect keyboard layout, influences text input but does not interfere with network communication.
Proper diagnosis involves reviewing power management configurations, ensuring wireless adapters are prioritized for performance over battery saving, and confirming network credentials. This targeted troubleshooting restores reliable network access without unnecessary hardware replacement or more extensive system modifications.
Question75
A desktop PC powers on with all fans spinning and LEDs illuminated, but there is no display output, and no POST beep codes are heard. Which of the following is the MOST likely cause?
A) Power supply failure
B) Faulty GPU
C) Loose keyboard connection
D) Incorrect monitor settings
Answer: A
Explanation:
When a system powers on partially but fails to display output or produce POST codes, power delivery is the primary concern. Option A, power supply failure, is the most likely cause. Even if fans and LEDs receive sufficient voltage to operate, the PSU may fail to provide stable power to the CPU, memory, or motherboard, preventing POST and system initialization. CompTIA 220-1201 highlights interpreting hardware indicators to distinguish between component failures and systemic power issues. Testing the PSU using a multimeter or swapping in a verified working unit can confirm the diagnosis.
Option B, a faulty GPU, might prevent display output, but most motherboards have integrated graphics, which allow POST to continue, often generating beep codes in case of GPU failure. The absence of beep codes suggests power or motherboard initialization issues rather than GPU-only problems.
Option C, a loose keyboard connection, may trigger minor BIOS warnings but does not prevent the system from completing POST or displaying output entirely.
Option D, incorrect monitor settings, affects the display image but does not prevent system boot or POST output.
Resolving this issue involves verifying the PSU output, ensuring proper cable connections, and replacing the PSU if it cannot deliver stable voltage. Understanding the symptoms of partial system power-on and differentiating between component-specific and systemic failures ensures accurate troubleshooting and efficient restoration of functionality.
When a desktop system exhibits partial power-on behavior—indicated by spinning fans and illuminated LEDs—but fails to display output or produce POST (Power-On Self-Test) codes, the issue is typically related to power delivery. The correct diagnosis requires understanding the architecture of modern PC hardware and the role each component plays during system initialization. In this case, Option A, power supply failure, is the most likely cause. The power supply unit (PSU) is responsible for converting alternating current (AC) from the wall outlet into direct current (DC) voltages required by the motherboard, CPU, GPU, memory, storage devices, and other peripherals. Even if the PSU allows LEDs and fans to operate, it may fail to provide the stable, regulated voltages needed for critical components, preventing the system from completing POST and initializing properly.
Power Supply Function and Failure Modes
The PSU supplies multiple voltage rails, typically +12V, +5V, and +3.3V, each with defined current limits. If any of these rails fail or fluctuate beyond acceptable tolerances, essential components such as the CPU and memory may not receive the necessary power to execute instructions during POST. Modern motherboards rely on clean, stable voltage to power chipset logic, memory modules, and integrated controllers. A failing PSU may produce enough power to spin fans or light LEDs, which require minimal current, but insufficient or unstable power for higher-demand components results in a complete failure to initialize the system.
There are multiple failure modes for a PSU that could cause these symptoms. Component degradation over time, such as aging capacitors, can reduce voltage stability, creating conditions where the system cannot boot. Sudden surges or drops in input voltage from the power source can also stress PSU components, leading to intermittent or permanent failure. Overheating of the PSU, either due to dust buildup, blocked vents, or fan malfunction, may trigger protective shutdowns or prevent it from delivering the necessary power to the motherboard. CompTIA 220-1201 emphasizes understanding these failure modes to differentiate between partial power-on scenarios and complete system failures.
Diagnostic Approach for PSU Failure
Diagnosing a PSU failure begins with visual and auditory inspection. Technicians should check for any burning odors, discoloration, or bulging capacitors, which indicate internal component failure. Additionally, measuring the output voltages with a multimeter can confirm whether the PSU delivers stable and correct voltages across all rails. Another practical diagnostic method is to swap the suspect PSU with a known working unit. If the system successfully completes POST and displays output, this confirms that the original PSU is faulty.
It is important to note that PSU failure is often misdiagnosed when technicians focus solely on peripheral symptoms like the absence of display output or system beeps. However, the presence of spinning fans and LEDs can be misleading; these components draw minimal power compared to the CPU and memory. Therefore, partial activity does not indicate a fully functioning PSU. CompTIA 220-1201 highlights interpreting hardware indicators, such as POST codes, fan operation, LED patterns, and diagnostic LEDs on motherboards, to distinguish between component-specific failures and systemic power issues.
Option B: Faulty GPU
A faulty GPU could theoretically prevent display output, but it rarely halts POST entirely on modern systems. Most contemporary motherboards include integrated graphics within the CPU or chipset. Even if the discrete GPU is malfunctioning or improperly seated, the system can often fall back to integrated graphics, allowing POST to complete. Additionally, many motherboards generate beep codes or LED indicators when a GPU failure is detected. The absence of such signals, combined with the lack of POST output, suggests that the issue lies elsewhere, typically in the power delivery path or motherboard initialization. While testing the GPU is an important step in display-related troubleshooting, in cases where no POST codes are generated, the PSU is a higher-priority suspect.
Option C: Loose Keyboard Connection
A loose keyboard connection may trigger minor BIOS or POST warnings, but it does not prevent the system from completing the boot process entirely. Keyboards communicate with the motherboard via USB or PS/2 interfaces, which are not required for POST to execute. If a keyboard is disconnected or malfunctioning, the system may display a message such as “Keyboard Not Detected” or halt briefly for input, but these issues do not result in a total lack of display or POST activity. Therefore, while ensuring proper peripheral connections is good practice, the symptoms described in this scenario point to a more systemic issue, namely the PSU.
Option D: Incorrect Monitor Settings
Incorrect monitor settings, such as an unsupported resolution or input source mismatch, affect only the video display. These settings do not prevent the motherboard from initializing, performing POST, or producing beep codes. A system with a functional PSU, CPU, and memory will continue to execute POST routines and attempt to output video signals regardless of monitor configuration. Testing the monitor by connecting it to another system or using an alternate monitor on the suspect system can quickly rule out display settings as the root cause. While monitor settings are a common cause of “no display” complaints, they are not relevant when the system fails to perform POST entirely.
Real-World Troubleshooting Considerations
When a system powers on partially, troubleshooting requires a systematic approach. First, visually inspect all power connections from the PSU to the motherboard and peripherals. Loose or damaged cables can mimic PSU failure symptoms. Next, isolate critical components: remove or disconnect non-essential hardware, such as additional hard drives, USB devices, or expansion cards. Attempting POST with minimal components—CPU, one memory module, motherboard, and PSU—helps identify whether the PSU can provide stable power under load. If the system still fails to POST, the PSU is highly likely to be the issue.
Technicians must also consider environmental factors that can influence PSU performance. High ambient temperatures or poor airflow can reduce efficiency and trigger protective shutdowns. Dust accumulation inside the PSU or on motherboard power circuits may impede cooling, leading to thermal protection mechanisms preventing system initialization. Ensuring a clean and cool operating environment can sometimes temporarily restore functionality, but persistent failure usually indicates internal PSU degradation.
Manufacturer-Specific Features and Diagnostic Tools
Many PSU manufacturers and motherboard vendors include diagnostic LEDs, self-test buttons, or integrated monitoring systems. For example, some motherboards display POST codes via onboard LEDs or digital displays, which can indicate whether the CPU, memory, or PSU is at fault. These diagnostic tools are invaluable in differentiating between component-specific failures and systemic power issues. Technicians following CompTIA 220-1201 guidelines leverage these tools to methodically narrow down the root cause, reducing unnecessary component replacement and ensuring accurate repair.
Preventive Measures and Best Practices
To prevent PSU-related failures, maintaining stable power delivery is essential. Using surge protectors, uninterruptible power supplies (UPS), and avoiding frequent voltage fluctuations extends PSU lifespan. Regular cleaning and monitoring of PSU temperature and performance help detect early signs of failure. Documenting component installation, replacement dates, and operational history assists in identifying patterns that may indicate degradation or impending failure. These preventive practices align with CompTIA 220-1201 objectives emphasizing proactive system maintenance and systematic troubleshooting.
In real-world scenarios, technicians often encounter situations where a system partially powers on, which can be misleading for novice users. The spinning fans and lit LEDs may give the impression that the system is receiving adequate power. However, these indicators require significantly less current than the CPU, memory, and motherboard chipset, which are essential for POST. The discrepancy between peripheral activity and system initialization highlights the importance of measuring actual voltage output across the PSU’s rails. Even minor fluctuations or insufficient amperage on the +12V or +5V rails can prevent the motherboard from powering critical subsystems, effectively halting POST without shutting down the fans.
A critical step in troubleshooting is performing a minimum boot configuration. This involves disconnecting all non-essential devices, such as secondary storage drives, expansion cards, and USB peripherals, leaving only the CPU, one memory module, the motherboard, and PSU connected. By simplifying the system, the technician can determine whether additional loads are contributing to the failure. If the system still fails to produce POST codes or display output, this confirms that the issue resides in the power delivery system or motherboard, further emphasizing PSU failure as the primary suspect.
Temperature and environmental factors should not be underestimated. Power supplies and motherboards have built-in thermal protection circuits. Overheating can cause the PSU to deliver inconsistent power or shut down temporarily to prevent damage. Dust accumulation inside the PSU or the case can impair airflow, reducing heat dissipation. In addition, repeated exposure to high ambient temperatures can degrade capacitor performance, leading to voltage instability and eventual failure. Proper maintenance, including periodic cleaning and ensuring adequate case ventilation, can extend PSU lifespan and prevent unexpected system failures.
Technicians also consider the age and quality of the PSU. Lower-quality power supplies may fail faster due to inferior components, insufficient cooling, or poor voltage regulation. High-end PSUs with robust circuitry, better capacitors, and protections such as overvoltage, undervoltage, overcurrent, and short-circuit prevention are less likely to cause sudden partial power-on issues. CompTIA 220-1201 emphasizes understanding component quality and lifespan as part of preventive maintenance and troubleshooting strategies.
Another aspect is the integration of modern PSU monitoring tools. Many PSUs and motherboards support software utilities that provide real-time voltage readings, current draw, and power efficiency metrics. These tools allow technicians to observe fluctuations during boot attempts, detect unstable voltage rails, and correlate symptoms with specific component failures. Such monitoring can identify borderline PSU issues before complete failure occurs, allowing proactive replacement.
Power supply failure also has implications beyond immediate system boot. Unstable or insufficient voltage can stress other components, potentially causing data corruption, unexpected shutdowns, or hardware damage. Therefore, identifying PSU issues promptly prevents cascading failures and protects the motherboard, CPU, and storage devices. Technicians must recognize this broader risk, reinforcing why PSU evaluation is the priority when a system exhibits partial power-on behavior.
Technicians following CompTIA guidelines document symptoms, test results, and component changes. This process ensures a repeatable workflow, reduces diagnostic errors, and facilitates knowledge sharing among support teams. Observing patterns, such as intermittent power-on failures or correlation with environmental conditions, often points directly to the PSU or motherboard, supporting a methodical resolution strategy.
By systematically verifying PSU function, isolating components, and utilizing monitoring tools, technicians can restore system functionality efficiently, prevent further damage, and ensure reliable long-term operation.