220-1101 Hardware and Network Troubleshooting Practice Test 9 — 15 Questions

Question 1

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 2

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.

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B. Bad SATA cable

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C. Failing power supply

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D. Loose RAM module

Question 3

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. The correct answer is C because 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.

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The UPS battery

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The thermal paste application

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The RAM modules

Question 4

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.

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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 5

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.

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The operating system power plan is set to Power Saver.

Question 6

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.

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Change the power plan to High Performance.

Question 7

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. Option D is 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

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Reseat all internal power and data cables

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Install a new motherboard immediately

Question 8

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.

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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.

Question 9

A user reports that their desktop computer cannot access any network shares. Other computers on the same switch can access the shares. The technician runs ipconfig /all on the affected computer and sees the following: IPv4 Address: 169.254.13.42, Subnet Mask: 255.255.0.0, Default Gateway: blank. Which of the following is the MOST likely cause?

Accepted Answer

The switch port the desktop is connected to is configured for the wrong VLAN.. The 169.254.x.x address is an Automatic Private IP Addressing (APIPA) address, assigned when a DHCP server is unreachable. Since other computers on the same switch can access network shares, the DHCP server is functional and has available addresses. The most likely cause is that the switch port is configured for the wrong VLAN, which isolates the desktop's broadcast domain, preventing it from reaching the DHCP server while other devices on the correct VLAN can communicate normally.

Answer

The desktop's network adapter is faulty.

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The DHCP server has no available IP addresses in its scope.

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The desktop's firewall is blocking DHCP traffic.

Question 10

A technician is troubleshooting a desktop PC that powers on (fans spin, LEDs light up) but does not display anything and produces no POST beeps. The motherboard has four diagnostic LEDs labeled CPU, DRAM, VGA, and BOOT. When the system is powered on, the DRAM LED remains solid red. The technician has verified that the RAM module (single 16GB DDR4 stick) is fully seated in slot A2, as recommended by the motherboard manual. The technician has also reseated the GPU and checked all power connections. Which of the following should the technician do NEXT?

Accepted Answer

Try a different RAM slot. The DRAM LED remaining solid red indicates a memory initialization failure. Since the single RAM stick is already fully seated in the recommended slot A2, the next logical step is to try a different RAM slot (e.g., A1 or B2) to rule out a faulty slot or a subtle contact issue. This is a standard first step in memory troubleshooting before replacing components.

Answer

Replace the motherboard

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Reinstall the CPU, checking for bent pins

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Update the motherboard BIOS

Question 11

A user reports that their desktop computer loses network connectivity intermittently. When the problem occurs, the link light on the network interface card (NIC) is off. The technician has replaced the Ethernet cable and tried a different port on the switch, but the issue persists. The technician notices that the desktop is located in a cubicle next to a large metal filing cabinet. Which of the following is the MOST likely cause of the intermittent connectivity?

Accepted Answer

Electromagnetic interference (EMI) from the metal cabinet. The large metal filing cabinet is likely acting as a source of electromagnetic interference (EMI), which can disrupt the electrical signals in the unshielded Ethernet cable. When the NIC's link light is off, it indicates a loss of physical layer connectivity, and EMI is a common cause of intermittent link drops in environments with large metal objects or power sources near data cabling.

Answer

Faulty router causing periodic DHCP lease failures

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Incorrect static IP address configuration on the desktop

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Duplicate IP address conflict on the network

Question 12

A technician is troubleshooting a desktop PC that fails to boot. When the power button is pressed, the system powers on for approximately 5 seconds, then shuts down and immediately restarts, repeating this cycle. The technician has replaced the power supply, reseated all components, and verified there are no loose screws or shorts. The motherboard has diagnostic LEDs, and the CPU LED glows solid red when the system attempts to start. The CPU is an Intel Core i7-12700K (LGA1700) installed in a compatible motherboard. The cooler is properly mounted with thermal paste applied. Which of the following is the MOST likely cause?

Accepted Answer

The motherboard BIOS version does not support the installed CPU.. The CPU LED glowing solid red indicates a CPU-related fault. Since the technician has already replaced the power supply, reseated components, and verified proper cooler mounting, the most likely cause is that the motherboard's BIOS version predates the microcode required for the Intel Core i7-12700K (Alder Lake, LGA1700). Many LGA1700 motherboards require a BIOS update to support 12th-gen CPUs; without it, the system fails to initialize the CPU, leading to the observed power cycle.

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The CPU cooler is not making sufficient contact with the CPU.

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The RAM modules are not fully seated in the correct slots.

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The power supply unit is delivering insufficient wattage on the +12V rail.

Question 13

A technician is troubleshooting a desktop PC that freezes for several seconds during disk-intensive operations, such as transferring large files. The technician has already replaced the hard drive with an SSD, tested the RAM with a memory diagnostic tool (no errors), and updated the chipset drivers. The issue still occurs. Which of the following is the MOST likely remaining cause of the freezes?

Accepted Answer

A faulty SATA cable. A faulty SATA cable can cause intermittent connectivity issues that manifest as system freezes during disk-intensive operations. Even after replacing the hard drive with an SSD and verifying RAM and drivers, a degraded or loose SATA cable can introduce data transfer errors or link drops, forcing the system to retry commands and causing pauses. This is the most likely remaining cause because the cable is the only component in the data path not yet replaced or tested.

Answer

Overheating CPU

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Incompatible RAM speed

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Outdated network drivers

Question 14

A technician installed a new high-end graphics card in a desktop PC. The system powers on, fans spin, but the monitor remains black. The monitor works fine when connected to the motherboard's integrated video port. The technician has reseated the graphics card, connected the necessary PCIe power cables, and verified the card is fully inserted in the primary PCIe x16 slot. Which of the following is the MOST likely next step to resolve the issue?

Accepted Answer

Check the BIOS/UEFI settings to ensure the primary display is set to PCIe. The correct answer is C because when a discrete graphics card is installed, the BIOS/UEFI must be configured to use the PCIe slot as the primary display adapter. If the system defaults to the integrated GPU, the monitor will remain black when connected to the new card, even though the card is powered and seated correctly. Checking and setting the primary display to PCIe in BIOS/UEFI directly addresses this common misconfiguration.

Answer

Replace the monitor with a 4K display

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Update the graphics card driver in Safe Mode

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Test the graphics card in another computer

Question 15

A technician is troubleshooting a desktop computer that experiences brief network disconnections lasting 5-10 seconds several times an hour. During the disconnections, the network activity and link lights on both the NIC and the switch remain illuminated. The technician has replaced the Ethernet cable, updated the NIC driver, and disabled power saving settings for the NIC. The issue persists. Which of the following should the technician do NEXT?

Accepted Answer

Perform a loopback test on the NIC. The correct next step is to perform a loopback test on the NIC. Since the link lights remain active during disconnections, the physical layer (cable, switch port) appears intact, and the issue persists after replacing the cable, updating the driver, and disabling power saving. A loopback test isolates whether the NIC itself can successfully send and receive data internally, ruling out internal NIC failure or a faulty transceiver without relying on external network traffic.

Answer

Check for an IP address conflict on the network

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Replace the network switch

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Review the system event logs for network-related errors