220-1101 Hardware and Network Troubleshooting — Timed 20 Questions

Question 1

A technician is troubleshooting a desktop computer that cannot connect to the internet. The computer has a static IP address of 192.168.1.100 with a subnet mask of 255.255.255.0 and a default gateway of 192.168.1.1. The technician can ping 127.0.0.1 successfully but cannot ping 192.168.1.1. The link lights on the NIC and the switch port are solid. Which of the following should the technician check NEXT?

20 minute time limit — choose an answer to begin.

Accepted Answer

Check the subnet mask configuration. The loopback ping (127.0.0.1) succeeds, confirming the TCP/IP stack is working. The solid link lights indicate Layer 1 connectivity is healthy. Since the technician cannot ping the default gateway (192.168.1.1), the next logical step is to verify the subnet mask. If the subnet mask is misconfigured such that the host considers 192.168.1.1 to be outside its local subnet, the host will not send an ARP request for the gateway's MAC address and will treat the gateway as unreachable; as a result, it cannot forward any traffic off the local segment. Checking the subnet mask configuration is the appropriate next step before replacing hardware or changing firewall settings.

Answer

Replace the network cable

Answer

Run the Windows network troubleshooter

Answer

Disable the Windows firewall

Question 2

A laser printer is printing pages with dark vertical streaks. The technician replaces the toner cartridge and the imaging drum, but the streaks persist. Which of the following components should the technician check NEXT?

Accepted Answer

Fuser assembly. The correct answer is A: Fuser assembly. Dark vertical streaks are typically caused by a damaged or contaminated drum, but if the drum and toner cartridge have been replaced and the issue persists, the fuser assembly is the next most likely culprit. The fuser roller can have a nick, scratch, or debris that creates pressure lines, resulting in dark streaks on the page. The transfer roller, on the other hand, is responsible for transferring toner from the drum to the paper and typically causes light or white streaks when faulty, not dark streaks.

Answer

Transfer roller

Answer

Paper tray rollers

Answer

Laser scanner mirror

Question 3

A user reports that their desktop computer loses network connectivity intermittently. The technician finds that the RJ45 connector on the cable has a broken retention clip, but replacing the cable does not resolve the issue. The computer is connected to a wall jack in the office. The technician uses a cable tester on the wall jack and discovers that pins 4 and 5 are open (no continuity). Which of the following is the MOST likely cause of the intermittent connectivity?

Accepted Answer

Incorrect wiring standard on the wall jack. Pins 4 and 5 correspond to the blue pair (pair 3) in both T568A and T568B wiring. While 10/100BASE-T Ethernet only uses pins 1, 2, 3, and 6, 1000BASE-T requires all four pairs. An open on pins 4 and 5 at the wall jack indicates the blue pair is not properly terminated. Since replacing the computer cable did not resolve the issue, the fault is in the wall jack termination. Intermittent connectivity can occur if the punch-down connection is loose, causing the blue pair to sometimes make contact; when the pair is needed for gigabit operation, the link may flap or fail.

Answer

Faulty network interface card (NIC) in the computer

Answer

Damaged patch cable at the patch panel in the server room

Answer

Malfunctioning switch port

Question 4

A user reports that their desktop computer frequently loses network connectivity for a few seconds, then reconnects. The technician replaces the Ethernet cable and the wall jack, but the problem persists. The computer is connected to a managed switch. The technician checks the switch logs and sees no errors or discards. Which of the following should the technician check NEXT?

Accepted Answer

Check the duplex and speed settings on the NIC and the switch port for a mismatch. The symptom of intermittent connectivity that persists after replacing the cable and wall jack suggests a configuration issue at the NIC or switch port. A duplex mismatch can cause brief outages, but it typically produces interface errors (collisions, CRC, runts) on the affected side. However, such errors may not appear in the switch's event log, since interface counters are separate from logged events. Therefore, the next logical step is to verify that the duplex and speed settings on the NIC and switch port match.

Answer

Disable and re-enable the network adapter in Device Manager

Answer

Update the network adapter driver from the manufacturer's website

Answer

Replace the switch port with a known-working port

Question 5

A laser printer produces light ghost images of previously printed text on the following page. The technician has already replaced the toner cartridge and the imaging drum with new OEM components. The fuser appears to be heating properly. Which of the following is the NEXT component the technician should inspect or replace?

Accepted Answer

Erase lamp. In a laser printer, the erase lamp is responsible for discharging the photoconductive drum after the image is transferred. If it fails, residual latent images from the previous cycle remain and produce light ghost images. The primary charge roller applies a uniform charge to the drum; it does not erase the previous charge pattern. Since the toner cartridge, imaging drum, and fuser have already been ruled out, the next component to inspect/replace is the erase lamp.

Answer

Transfer roller

Answer

Primary charge corona / charge roller

Answer

Laser scanner unit

Question 6

A technician is troubleshooting a desktop computer that cannot connect to the internet. The computer has a static IP address of 192.168.1.100 with a subnet mask of 255.255.255.0 and a default gateway of 192.168.1.1. The technician can ping 127.0.0.1 successfully but cannot ping 192.168.1.1. The link lights on the NIC and the switch port are solid. Which of the following should the technician check NEXT?

20 minute time limit — choose an answer to begin.

Accepted Answer

B. (Clear CMOS) because the symptoms—power-on with all fans spinning, USB power present, but no display despite a solid monitor power LED—indicate a POST failure that persists after reseating the RAM. Since no diagnostic LEDs or speaker are available, the next best step is to clear the CMOS. This resets the BIOS/UEFI settings to default, which can resolve problems caused by incorrect video output configuration, memory timing errors, or overclocking that prevents the system from initializing the display.

Answer

A

Answer

C

Answer

D

Question 7

A user reports that their desktop computer loses network connectivity for several seconds whenever they open a large file transfer program. The technician checks the NIC properties and sees that the link speed is 100 Mbps, but the switch port is set to auto-negotiate and advertises up to 1000 Mbps (full duplex). The cable is a Cat5e cable that runs through the ceiling. Other computers in the same office have gigabit connections to the same switch. Which of the following is the MOST likely cause of the intermittent connectivity?

Accepted Answer

The Ethernet cable is damaged or has excessive length, causing the NIC to negotiate a lower speed.. The most likely cause is a damaged or excessively long Cat5e cable, assuming the switch port is set to auto-negotiate (capable of 1000 Mbps). The cable fault causes the NIC to fall back to 100 Mbps. During high traffic from the file transfer program, the marginal cable produces errors, causing intermittent link drops. The fact that other computers achieve gigabit on the same switch suggests the switch is not the issue, though the specific port configuration should be verified.

Answer

The switch port has a duplex mismatch.

Answer

The file transfer program is using an incompatible protocol.

Answer

The NIC driver is outdated and not compatible with gigabit.

Question 8

A user reports that their desktop computer shuts down randomly after about 10 minutes of use. The technician checks the event log and sees thermal warnings. The technician has verified that all fans are spinning and the CPU heatsink is properly attached. Which of the following should the technician do NEXT?

Accepted Answer

Apply new thermal paste between the CPU and heatsink.. The thermal warnings in the event log indicate that the CPU is overheating despite the fans spinning and the heatsink being properly attached. Over time, thermal paste can dry out or become less effective, reducing heat transfer from the CPU to the heatsink. Applying new thermal paste restores proper thermal conductivity, which is the most likely fix given the symptoms.

Answer

Replace the power supply.

Answer

Update the BIOS firmware.

Answer

Replace the CPU.

Question 9

A user reports that their laptop’s Wi-Fi connection is slow and drops frequently, but only when they are in the break room. Other laptops in the same area have no issues. The technician tests the signal strength in the break room and it is excellent. Which of the following is the most likely cause?

Accepted Answer

Interference from a microwave oven. The issue occurs only in the break room, indicating an environmental factor at that location. Other laptops work fine, so the access point is not overloaded, and the signal strength is excellent, ruling out range problems. A microwave oven is a common source of interference in break rooms, affecting Wi-Fi on the 2.4 GHz band. Since the problem is location-specific and the laptop works elsewhere, a faulty wireless adapter is unlikely.

Answer

The laptop’s wireless adapter is malfunctioning

Answer

The access point is overloaded with too many clients

Answer

The laptop is connected to the 5 GHz band which has shorter range

Question 10

A user reports that their desktop computer shuts down randomly after about 15 minutes of use. A technician checks the event log and finds a critical error related to a thermal event. The technician has verified that the CPU heatsink fan and all case fans are spinning, and the heatsink is securely attached. However, the computer still shuts down. Which of the following should the technician do NEXT?

Accepted Answer

Check the CPU thermal paste application.. The technician has already verified that the CPU heatsink fan and case fans are spinning and the heatsink is securely attached, which rules out a loose cooler or a failed fan. The critical thermal event error indicates the CPU is overheating despite these checks, so the most likely remaining cause is degraded or improperly applied thermal paste, which prevents efficient heat transfer from the CPU die to the heatsink. Reapplying high-quality thermal paste is the standard next step before considering component replacement.

Answer

Replace the power supply unit.

Answer

Update the BIOS firmware.

Answer

Replace the CPU.

Question 11

A technician is troubleshooting a desktop computer that cannot connect to the internet. The computer has a static IP address of 192.168.1.100 with a subnet mask of 255.255.255.0 and a default gateway of 192.168.1.1. The technician can ping 127.0.0.1 successfully but cannot ping 192.168.1.1. The link lights on the NIC and the switch port are solid. Which of the following should the technician check NEXT?

20 minute time limit — choose an answer to begin.

Accepted Answer

Verify that the monitor cable is securely connected to both the monitor and the graphics card.. The 1 long, 2 short beep code indicates a video adapter failure. Since reseating the graphics card did not resolve it, the next step is to test or replace the graphics card. Checking the monitor cable is not appropriate because the beep code occurs during POST before display initialization; the BIOS has already detected a video problem independent of the cable.

Answer

Replace the power supply unit.

Answer

Test the RAM in a different computer.

Answer

Update the motherboard BIOS.

Question 12

A user reports that their desktop computer loses network connectivity for a few seconds every time they operate a large power tool (e.g., an electric saw) in the same room. 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 is the MOST likely cause of the intermittent disconnects?

Accepted Answer

Electromagnetic interference (EMI) from the power tool affecting the Ethernet cable. The large power tool generates significant electromagnetic interference (EMI) when operating, which can induce noise in the unshielded Ethernet cable, causing temporary signal degradation and loss of link. Since the technician has already ruled out the cable, switch port, and NIC driver, EMI from the tool is the most likely remaining cause.

Answer

Radio frequency interference (RFI) from the power tool's motor

Answer

An IP address conflict with the power tool's network interface

Answer

The DHCP lease is being forced to renew due to the power tool's operation

Question 13

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 link light being off indicates a loss of physical layer connectivity. While EMI can cause intermittent link drops, a large metal filing cabinet is a passive object and does not generate electromagnetic interference. The actual cause is more likely a faulty NIC, a damaged cable, or EMI from a nearby electrical source such as a motor or fluorescent light. Therefore, none of the given options accurately describes the most likely cause.

Answer

Faulty router causing periodic DHCP lease failures

Answer

Incorrect static IP address configuration on the desktop

Answer

Duplicate IP address conflict on the network

Question 14

A technician is troubleshooting a desktop computer that cannot connect to the internet. The computer has a static IP address of 192.168.1.100 with a subnet mask of 255.255.255.0 and a default gateway of 192.168.1.1. The technician can ping 127.0.0.1 successfully but cannot ping 192.168.1.1. The link lights on the NIC and the switch port are solid. Which of the following should the technician check NEXT?

20 minute time limit — choose an answer to begin.

Accepted Answer

The default gateway on the PC is misconfigured.. The PC can ping the default gateway (192.168.1.1) and access local resources by IP, indicating that local Layer 2/3 connectivity is functional. However, pinging an external IP (8.8.8.8) fails while another PC on the same network succeeds. This isolates the issue to this specific PC. Since the PC uses a static IP and can reach the gateway, the most likely cause is that the default gateway is misconfigured—the IP 192.168.1.1 might not be the actual router (it could be another device that does not route traffic). As a result, external traffic is sent to a device that does not forward it to the internet. The other PC with a correct gateway (the actual router) can reach external IPs. This is a common CompTIA A+ troubleshooting scenario.

Answer

The PC's subnet mask is incorrect.

Answer

The router's network address translation (NAT) is malfunctioning.

Answer

The DNS server setting is incorrect.

Question 15

A user reports that their desktop computer shuts down unexpectedly after about 10 minutes of use. The computer can be turned back on immediately after shutdown, and no error messages are displayed. The technician suspects the CPU is overheating. Which of the following steps should the technician take FIRST to confirm this suspicion?

Accepted Answer

Enter the system BIOS/UEFI and check the temperature monitor.. The technician should first enter the system BIOS/UEFI to check the CPU temperature monitor. This is the quickest, non-invasive step to confirm if the CPU is overheating, as the BIOS/UEFI provides real-time temperature readings without requiring hardware disassembly. If the temperature is abnormally high (e.g., above 90°C at idle or under load), it confirms the overheating suspicion.

Answer

Replace the thermal paste on the CPU.

Answer

Remove the CPU cooler and inspect the fan.

Answer

Update the system firmware.

Question 16

After a thunderstorm, a user reports that their desktop computer cannot connect to the network. The technician observes that the Ethernet port on the computer has a steady green link light but no amber activity light. The switch port corresponding to the user's cable also shows a link light. The computer's operating system shows an IP address of 169.254.1.10. Which of the following is the MOST likely cause?

Accepted Answer

The Ethernet cable has been damaged and is causing frame errors. The 169.254.1.10 IP address is an Automatic Private IP Addressing (APIPA) address (169.254.0.0/16, per RFC 3927), which Windows assigns when DHCP fails. The steady green link light on both the NIC and switch indicates Layer 1 connectivity is intact, but the absence of an amber activity light suggests no data frames are passing. Damaged cabling can cause excessive frame errors or collisions, preventing successful DHCP discovery (broadcast) and data transmission while still allowing the link light to illuminate, as link detection only requires an electrical connection, not error-free communication.

Answer

The network interface card (NIC) has been damaged by a power surge

Answer

The switch port was disabled by the storm

Answer

The router's DHCP server failed after the storm

Question 17

A technician is troubleshooting a desktop computer that cannot connect to the internet. The computer has a static IP address of 192.168.1.100 with a subnet mask of 255.255.255.0 and a default gateway of 192.168.1.1. The technician can ping 127.0.0.1 successfully but cannot ping 192.168.1.1. The link lights on the NIC and the switch port are solid. Which of the following should the technician check NEXT?

20 minute time limit — choose an answer to begin.

Accepted Answer

Video card. The one long beep followed by two short beeps is a common beep code (often associated with Award BIOS) indicating a video card error. Since the computer powers on and fans spin, the power supply and basic motherboard functions are working, but the black screen points to a failure in the video subsystem. This makes the video card the most likely culprit.

Answer

CPU

Answer

RAM

Answer

Power supply

Question 18

A user reports that their workstation experiences intermittent network drops and slow speeds. The technician checks the switch port status and notices a high number of late collisions. The workstation's network adapter is set to auto-negotiate. The switch port is also set to auto-negotiate but the technician observes that the link has negotiated at 100 Mbps half-duplex. Which of the following is the MOST likely cause of this issue?

Accepted Answer

Duplex mismatch between the workstation NIC and the switch port. Late collisions are a classic symptom of a duplex mismatch. In this scenario, the switch port has negotiated to 100 Mbps half-duplex, which means the switch is operating at half-duplex. If the workstation NIC is actually operating at full-duplex—possibly due to a failed auto-negotiation process or a driver-level forced setting—the mismatch causes the switch to detect late collisions. The full-duplex workstation does not perform carrier sensing, so the half-duplex switch can transmit at the same time and later receive a collision, which it registers as a late collision because it occurs after the collision window.

Answer

Faulty Ethernet cable causing excessive crosstalk

Answer

Incorrect VLAN assignment on the switch port

Answer

IP address conflict on the network

Question 19

A technician is troubleshooting a workstation that cannot connect to the network. The technician sees that the Ethernet cable used is a crossover cable. The workstation's network adapter supports Auto-MDI/X. The switch port does not have any link light. Which of the following is the MOST likely reason for the lack of connectivity?

Accepted Answer

The crossover cable is faulty. The NIC supports Auto-MDI/X, so it can automatically adjust its internal crossover configuration for either a straight-through or crossover cable, regardless of the switch's support. Since the switch port has no link light, the crossover cable itself is not the issue (the NIC can handle it). The most likely reason is a defective cable, making option A correct.

Answer

The switch does not support Auto-MDI/X

Answer

The NIC driver is out of date

Answer

The cable length exceeds 100 meters

Question 20

A technician is troubleshooting a laser printer that produces pages with vertical black streaks running from the top to the bottom of the page. The technician has already replaced the toner cartridge and the drum unit, but the problem persists. Which printer component should the technician inspect or replace NEXT?

Accepted Answer

Fuser assembly. Vertical black streaks that persist after replacing the toner cartridge and drum unit are most likely caused by a damaged fuser assembly. The fuser uses heat and pressure to bond toner to the paper; if its roller is scratched or contaminated, it can leave continuous black streaks. Since the toner and drum have been replaced and the problem continues, the fuser is the next component to inspect.

Answer

Transfer roller

Answer

Laser scanner assembly

Answer

Paper pickup roller