220-1101 Hardware and Network Troubleshooting Practice Test 10 — 15 Questions

Question 1

A user reports that their desktop computer loses network connectivity for a few seconds whenever they start a large video rendering application. The technician has already updated the network adapter driver, replaced the Ethernet cable, and verified that the switch port is not faulty. The computer uses an integrated NIC on the motherboard. The system's CPU and GPU temperatures are within normal limits during rendering. Which of the following is the MOST likely cause of the intermittent network drops?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

The power supply unit (PSU) is failing under load.. When a large rendering application starts, it draws significant power from the PSU. If the PSU is failing or underrated, the voltage supplied to the integrated NIC may drop below its operational threshold, causing the NIC to momentarily reset or lose link. This explains the intermittent drops despite the NIC, cable, and switch port being verified as functional.

Answer

The rendering application is saturating the network bandwidth.

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The motherboard's chipset is overheating.

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There is an IRQ conflict between the NIC and the graphics card.

Question 2

A technician notices a constant high-pitched whine coming from the power supply area of a desktop computer. The computer boots and operates normally under all workloads. The technician has already checked that all fans are free of obstructions and that no cables are touching the fan blades. Which of the following components is most likely causing the noise?

Accepted Answer

Power supply coil whine due to electrical resonance. A constant high-pitched whine from the power supply area, especially when the system operates normally under all workloads, is characteristic of coil whine. This occurs when electrical current passes through an inductor (coil) in the power supply, causing the coil's windings to vibrate at a frequency within the audible range due to electrical resonance. Since the noise is not mechanical (fans are clear) and the system functions correctly, coil whine is the most likely cause.

Answer

Faulty CPU fan bearing

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Defective power supply capacitor

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Loose mounting screw vibrating

Question 3

A user reports that their wired desktop computer loses network connectivity for a few seconds at random times. The technician observes that when the issue occurs, the network activity LED on the integrated NIC turns off. The technician has already replaced the Ethernet cable, tested the switch port with another device (which works fine), and updated the NIC driver. Which of the following should the technician check NEXT?

Accepted Answer

B) Check the NIC's power management settings in Device Manager and disable 'Allow the computer to turn off this device to save power'. The symptom—random, brief connectivity loss with the NIC activity LED turning off—strongly suggests the operating system is powering down the NIC to save energy. Disabling the 'Allow the computer to turn off this device to save power' setting in the NIC's power management properties prevents the OS from entering a low-power state that drops the link. Since the cable, switch port, and driver have already been verified, this is the logical next step.

Answer

A) Replace the motherboard

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C) Disable IPv6 on the NIC

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D) Manually set the NIC speed and duplex to 10 Mbps Full Duplex

Question 4

A technician is troubleshooting a workstation that intermittently loses network connectivity. The workstation has an integrated Gigabit Ethernet NIC. During an outage, the technician checks the network adapter status in the operating system and sees 'Network cable unplugged' even though the cable is securely connected to both the workstation and the switch. The technician has already replaced the Ethernet cable, the switch port, and the NIC driver. The issue occurs more frequently when the workstation's power supply is under heavy load (e.g., during gaming). Which of the following is the MOST likely cause?

Accepted Answer

The power supply unit (PSU) is failing and cannot provide stable voltage to the motherboard under load, causing the integrated NIC to drop link.. The intermittent loss of connectivity under heavy PSU load, combined with the 'Network cable unplugged' message despite a known-good cable and switch port, points to voltage instability from a failing PSU. When the PSU cannot maintain stable voltage to the motherboard, the integrated Gigabit Ethernet NIC may drop its link because the PHY (physical layer transceiver) requires a clean power rail to maintain the 1000BASE-T signal. This is a classic symptom of a failing PSU causing link drops under load, not a cable or driver issue.

Answer

Electromagnetic interference (EMI) from power cables running near the Ethernet cable is disrupting the signal.

Answer

The workstation has a duplicate IP address on the network, causing intermittent disconnections.

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The switch port is experiencing a broadcast storm, flooding the network interface.

Question 5

A technician is troubleshooting a workstation that loses network connectivity for a few seconds at random intervals. The technician observes that during the outage, the network icon in the system tray shows 'Unidentified network' or 'No internet access', but the IP configuration still shows a valid address from DHCP. The technician has already replaced the NIC and the Ethernet cable. Which of the following should the technician check NEXT?

Accepted Answer

Check the speed and duplex settings on both the NIC and the switch port. The symptom of intermittent connectivity with a valid DHCP address but 'Unidentified network' or 'No internet access' points to a Layer 2 issue, often caused by a speed/duplex mismatch between the NIC and the switch port. When one side is set to auto-negotiation and the other is manually set (or fails to negotiate), the link may appear up but drops frames, causing brief outages. Since the NIC and cable have already been replaced, checking and aligning the speed and duplex settings on both ends is the logical next step.

Answer

Verify that the DNS server is reachable and responsive

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Disable the Windows firewall temporarily

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Increase the DHCP lease time on the router

Question 6

A user reports that their desktop computer loses network connectivity for a few seconds whenever they start a large video rendering application. The technician has already updated the network adapter driver, replaced the Ethernet cable, and verified that the switch port is not faulty. The computer uses an integrated NIC on the motherboard. The system's CPU and GPU temperatures are within normal limits during rendering. Which of the following is the MOST likely cause of the intermittent network drops?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Check the wall outlet voltage with a multimeter.. The technician has already ruled out the PSU, overheating, driver issues, and faulty RAM. Random restarts under load can be caused by unstable or insufficient AC power from the wall outlet. Using a multimeter to check the wall outlet voltage is the logical next step to identify if the issue is upstream of the PSU, such as a sagging voltage or a loose neutral connection.

Answer

Replace the motherboard.

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Disable automatic restart in Windows System Properties.

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Run a stress test on the GPU.

Question 7

A technician is troubleshooting a user's desktop computer that intermittently loses network connectivity. The issue occurs only when the building's central air conditioning (HVAC) system turns on. The technician has already replaced the Ethernet cable, the NIC (network interface card), and the switch port. The computer is connected to a surge protector and the power cabling is properly routed. Which of the following is the MOST likely cause of the intermittent connectivity?

Accepted Answer

Electromagnetic interference (EMI) from the HVAC motor. The HVAC motor generates a strong electromagnetic field when it starts, which can induce current in nearby unshielded Ethernet cables, corrupting the data signal and causing intermittent connectivity. This is a classic example of electromagnetic interference (EMI), and the fact that the issue correlates precisely with the HVAC system turning on, combined with the replacement of the cable, NIC, and switch port, points directly to an external interference source.

Answer

IP address conflict due to DHCP lease expiration

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Faulty switch port

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DNS server unavailability

Question 8

A user reports intermittent network connectivity on a desktop computer. The technician observes that the Ethernet link light on the NIC turns off for a few seconds and then turns back on. The cable passes a wiremap test, the switch port is verified good with another device, and the NIC driver is updated. The issue occurs more frequently when the computer's case fan runs at high speed. Which of the following is the MOST likely cause?

Accepted Answer

Electromagnetic interference from the case fan. The intermittent link light behavior, combined with the correlation to the case fan running at high speed, points to electromagnetic interference (EMI) from the fan motor. EMI can disrupt the electrical signals in the unshielded twisted-pair (UTP) cable, causing the NIC to lose link momentarily. Since the cable passes a wiremap test and the switch port works with another device, the issue is environmental, not a hardware fault.

Answer

Faulty NIC (Network Interface Card)

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Incorrect pinout of the Ethernet cable

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Driver conflict with the fan controller

Question 9

A technician is troubleshooting a desktop computer that fails to boot and displays the error message 'Boot device not found'. The technician has verified that the hard drive is detected in the BIOS and that the boot order is set correctly. The hard drive is spinning and appears to be receiving power. Which of the following is the MOST likely cause of this issue?

Accepted Answer

A. Corrupted MBR/GPT. Since the hard drive is detected in BIOS, spinning, and receiving power, the issue is not a hardware connection or power failure. The 'Boot device not found' error with correct boot order indicates that the bootloader (MBR or GPT) is corrupted or missing, preventing the system from reading the boot sector to load the operating system.

Answer

B. Bad SATA cable

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C. Failing power supply

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D. Loose RAM module

Question 10

A technician is troubleshooting a server that randomly shuts down after running for about 30 minutes. The server has dual power supplies and is connected to a UPS. The technician has already replaced the CPU cooler and verified that all fans are spinning. The temperature readings for the CPU and motherboard are within normal range. Which component should the technician check NEXT?

Accepted Answer

The power supply voltage rails. Random shutdowns after a consistent runtime (30 minutes) often indicate a failing power supply that cannot maintain stable output under sustained load. The technician has already ruled out overheating by replacing the CPU cooler, verifying fan operation, and confirming normal temperature readings. Checking the power supply voltage rails with a multimeter or PSU tester can reveal sagging voltages or ripple that cause intermittent shutdowns, even when the system appears to run initially.

Answer

The UPS battery

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The thermal paste application

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The RAM modules

Question 11

A technician is troubleshooting a desktop computer that connects to the network but experiences slow data transfers. The network uses a Gigabit Ethernet switch. The technician checks the network adapter status and sees that the link speed is 100 Mbps. The cable connecting the computer to the wall jack is a Cat5 cable. Which of the following is the MOST likely cause of the reduced speed?

Accepted Answer

The cable is not certified for Gigabit Ethernet.. Cat5 cable is only certified for Fast Ethernet (100 Mbps) and does not meet the stricter specifications required for Gigabit Ethernet (1000 Mbps). While Cat5e or Cat6 cables are needed for reliable 1000BASE-T operation, a standard Cat5 cable will often force the link to negotiate down to 100 Mbps, causing the observed slow transfer speeds.

Answer

The network adapter is configured for half-duplex.

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The switch port has been administratively disabled.

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The computer's operating system is outdated.

Question 12

A technician is troubleshooting a high-end gaming desktop that randomly restarts under heavy GPU load. The technician has already replaced the power supply with a unit that provides sufficient wattage, verified that CPU and GPU temperatures are within normal limits, and tested the RAM with a memory diagnostic (no errors). The GPU is a high-end model that requires two 8-pin PCIe power connectors. Which of the following is the MOST likely remaining cause of the random restarts?

Accepted Answer

The GPU is connected using a single 8-pin power cable with a daisy-chain pigtail for the second connector.. The random restarts under heavy GPU load are most likely caused by using a single 8-pin PCIe power cable with a daisy-chain pigtail to supply both 8-pin connectors on a high-end GPU. Each 8-pin PCIe connector can deliver up to 150W, and the PCIe slot provides 75W, totaling 375W for a card that may draw 300W or more under load. A single cable with a pigtail forces all current through one connector and wire gauge, causing voltage drop, overheating, or triggering overcurrent protection (OCP) on the power supply, leading to restarts.

Answer

The motherboard BIOS needs to be updated to support the GPU.

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The RAM is not installed in the correct dual-channel slots.

Answer

The operating system power plan is set to Power Saver.

Question 13

A user reports that their laptop loses network connectivity whenever they unplug the AC power adapter. When running on battery power alone, the laptop's Wi-Fi works intermittently or disconnects. The technician has verified that the Wi-Fi adapter driver is up to date and that the router is functioning correctly. Which of the following should the technician do NEXT to resolve this issue?

Accepted Answer

Disable the power-saving feature for the wireless adapter in Device Manager.. The issue is that the Wi-Fi adapter disconnects when the laptop switches to battery power, which is a classic symptom of the power-saving feature for the wireless adapter being enabled. This feature, controlled via the Power Management tab in Device Manager, can reduce power to the adapter to conserve battery life but often causes intermittent connectivity or disconnects. Disabling 'Allow the computer to turn off this device to save power' resolves the problem without replacing hardware or changing the overall power plan.

Answer

Replace the Wi-Fi adapter.

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Update the BIOS firmware.

Answer

Change the power plan to High Performance.

Question 14

A desktop computer will not boot. When the power button is pressed, the power LED lights up briefly and then turns off. The technician suspects a possible short circuit. Which of the following is the BEST first step to isolate the issue?

Accepted Answer

Remove the motherboard and test it outside the case on a non-conductive surface. The best first step because the symptom—power LED briefly lighting then shutting off—strongly suggests a short circuit, often caused by a motherboard standoff or loose screw contacting the case. Removing the motherboard and testing it on a non-conductive surface (e.g., cardboard or the motherboard box) isolates the motherboard from the case, allowing the technician to determine if the short is due to case contact or a component-level fault. This is a standard CompTIA A+ troubleshooting step for suspected shorts before replacing parts.

Answer

Replace the power supply with a known good unit

Answer

Reseat all internal power and data cables

Answer

Install a new motherboard immediately

Question 15

A technician is troubleshooting a workstation that randomly reboots when the user performs disk-intensive operations, such as copying large files. The technician has replaced the power supply and tested the RAM (no errors). The hard drive passes S.M.A.R.T. tests. The motherboard capacitors appear normal. The technician suspects a thermal issue but CPU and GPU temps are normal. Which component should the technician check next?

Accepted Answer

The voltage regulator modules (VRMs) on the motherboard, which may be overheating under load.. The VRMs regulate voltage to the CPU and can overheat under sustained load, especially during disk-intensive operations that also stress the CPU. Overheating VRMs can cause voltage instability or thermal shutdown, leading to random reboots even when CPU/GPU temperatures appear normal. This matches the symptom pattern after ruling out PSU, RAM, and storage issues.

Answer

The SATA data cable, which may be faulty causing intermittent disconnects.

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The case fans, which may not be providing adequate airflow to the chipset.

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The operating system power plan settings, which may be set to balanced.