220-1101 Hardware and Network Troubleshooting — 40 Questions

Question 1

After a power outage, a desktop computer will not power on. The PSU fan does not spin, and no LEDs are lit. The technician tests the power supply with a PSU tester; all voltages are within spec. A multimeter reading at the motherboard's power button header shows 3.3V when the button is pressed. The power supply is also confirmed to work when tested in another system. What is the most likely cause?

Accepted Answer

The motherboard has failed. The motherboard has failed because the PSU passes all voltage tests and works in another system, yet the desktop shows no signs of power (no fan spin, no LEDs) when connected to this motherboard. The 3.3V reading at the power button header indicates the motherboard is receiving standby power and the button is functioning, but the motherboard is not completing the power-on sequence (pulling PS_ON# low) to start the PSU. This points to a failed motherboard, likely a short or damaged power regulation circuit.

Answer

The power supply is still faulty despite the tester showing good voltages

Answer

The power button is faulty

Answer

The BIOS has become corrupted

Question 2

A network printer is set to a static IP address. Users report that print jobs spool on their workstations but never print. The technician confirms the printer is powered on, the network cable is connected, and the printer's self-test page prints successfully. The technician can ping the printer's IP address from a workstation. Which of the following is the MOST likely cause of the issue?

Accepted Answer

The printer's print queue is paused or the printer is in an 'Offline' state on the print server. The printer is reachable (ping succeeds) and its self-test page prints, confirming basic network connectivity and hardware functionality. The fact that print jobs spool locally but never print indicates the print server is not forwarding jobs to the printer, which is classic behavior when the printer queue is paused or the printer is marked offline on the print server. This prevents the spooler from sending data to the printer even though the network path is intact.

Answer

The printer driver on the workstations is incorrect

Answer

The printer's static IP address conflicts with another device on the network

Answer

The network cable is faulty

Question 3

A user reports that after moving their desktop computer to a new desk, the network connection no longer works. The technician notices that the Ethernet cable is plugged into the computer and the wall jack, but the link lights on the computer's NIC and the wall jack are off. The cable is a flat-style Cat5e cable that came with the computer. Which of the following is the most likely cause?

Accepted Answer

The cable is damaged from bending. Flat-style Ethernet cables are more susceptible to damage from bending or kinking than round cables because their conductors are arranged in a parallel plane, which can cause conductor fractures or impedance mismatches when flexed. Since the cable was moved and the link lights are off on both the NIC and the wall jack, the most likely cause is physical damage to the cable from bending during the move, breaking the electrical continuity.

Answer

The cable is not Cat6

Answer

The wall jack is not terminated properly

Answer

The NIC is disabled in the OS

Question 4

A network laser printer displays 'Replace imaging drum' on its control panel. The technician installs a new imaging drum, but the next day the message reappears and users report faded prints. Which of the following is the most likely cause?

Accepted Answer

The drum was not reset after installation. The 'Replace imaging drum' message persists and prints are faded because the printer's maintenance counter for the drum unit was not reset after installing the new drum. Most laser printers track drum life via a page count or a rotation counter; replacing the physical drum without resetting this counter leaves the printer believing the old, worn drum is still installed, causing it to continue displaying the warning and potentially reducing toner transfer efficiency, leading to faded output.

Answer

The printer firmware is out of date

Answer

The toner cartridge is low

Answer

The main logic board is failing

Question 5

A user reports that their desktop computer can connect to the local network and access shared folders, but cannot browse the internet. Other computers on the same network work fine. The technician checks the IP configuration and sees the computer has a valid IP address of 192.168.1.100 with a default gateway of 192.168.1.1. The computer can successfully ping 192.168.1.1 and 8.8.8.8, but cannot ping 'google.com'. Which of the following should the technician check FIRST?

Accepted Answer

Verify that the DNS server address is configured correctly on the workstation.. The computer can ping 8.8.8.8 (a public IP address) but cannot ping 'google.com' (a domain name). This indicates that IP connectivity to the internet is working, but name resolution is failing. The most likely cause is a misconfigured or unreachable DNS server. The technician should first verify the DNS server address in the workstation's IP configuration, as this is the quickest and most direct step to resolve the symptom.

Answer

Check the proxy settings in the web browser.

Answer

Replace the network cable connecting the computer to the wall jack.

Answer

Disable the Windows Firewall on the computer.

Question 6

A user reports that their desktop computer intermittently loses network connectivity. The computer uses a USB Wi-Fi adapter. The technician notices that the adapter feels warm during use and the connection drops most often when the computer has been running for a while. Other devices on the same wireless network work fine. Which of the following is the MOST likely cause of the issue?

Accepted Answer

The USB port not providing enough power. The USB Wi-Fi adapter feels warm and drops connectivity after prolonged use, which indicates thermal stress from insufficient power delivery. USB ports have a maximum current output (typically 500mA for USB 2.0 or 900mA for USB 3.0), and if the adapter draws more power than the port can supply, the voltage drops, causing the adapter to overheat and disconnect. Other devices on the same network work fine, ruling out wireless interference or network-side issues, and the intermittent nature tied to runtime points directly to power starvation rather than a driver or cable fault.

Answer

Wireless interference from nearby devices

Answer

A faulty USB cable connected to the adapter

Answer

A driver conflict with the Wi-Fi adapter

Question 7

A user reports that their laptop's external monitor connected via HDMI is not detected. The technician tested the external monitor with another laptop and it works. The laptop's built-in display functions normally. Which of the following should the technician try NEXT?

Accepted Answer

Press the function key (e.g., Fn+F4) to toggle display output. The external monitor works with another laptop, so the monitor and HDMI cable are functional. The laptop's built-in display works, indicating the graphics hardware is operational. Pressing the function key (e.g., Fn+F4) toggles the display output mode (e.g., extend, duplicate, external only) and is the quickest way to resolve a display detection issue caused by the laptop's display mode being set to internal-only.

Answer

Update the graphics driver

Answer

Replace the HDMI cable

Answer

Reinstall the operating system

Question 8

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?

Accepted Answer

Check the subnet mask configuration. The technician can ping 127.0.0.1 (loopback) successfully, confirming the TCP/IP stack is working on the host. However, they cannot ping the default gateway 192.168.1.1, and the link lights are solid, indicating Layer 1 (physical) connectivity is good. The most likely cause is an incorrect subnet mask; a mask of 255.255.255.0 is correct for a /24 network, but if the actual network uses a different mask (e.g., /16 or /23), the host may believe the gateway is on a different subnet and will not send ARP requests for it, causing the ping to fail. Checking the subnet mask configuration is the logical next step before replacing cables or disabling firewalls.

Answer

Replace the network cable

Answer

Run the Windows network troubleshooter

Answer

Disable the Windows firewall

Question 9

A technician is troubleshooting a desktop computer that will not boot. The CPU cooler fan spins, but the graphics card (GPU) fan is not spinning, and there is no display on the monitor. The power supply was tested in another system and works. Which of the following is the MOST likely cause?

Accepted Answer

The graphics card is faulty or not receiving power. The CPU cooler fan spinning indicates the motherboard is receiving power and the PSU is functional, but the GPU fan not spinning and no display output point to the graphics card as the most likely culprit. The GPU may be faulty, improperly seated in its PCIe slot, or missing its required auxiliary power connectors (6/8-pin PCIe power cables), preventing it from initializing and producing a video signal.

Answer

The motherboard has a short circuit

Answer

The RAM modules are not seated properly

Answer

The power button is stuck

Question 10

A technician is troubleshooting a network laser printer that prints blank pages even though the toner cartridge is new and properly installed. The printer's self-test page also comes out blank. Which of the following should the technician check first?

Accepted Answer

The imaging drum for exposure or contact issues.. The imaging drum is responsible for transferring the toner image to the paper. A new toner cartridge does not include a new drum in many laser printers; if the drum is worn, damaged, or has a contact issue, it will not charge or discharge correctly, resulting in blank pages even on a self-test page. Since the self-test page also fails, the problem is internal to the printer hardware, not the network or driver.

Answer

The fuser assembly for wear or damage.

Answer

The network connection and IP configuration.

Answer

The printer driver settings on the user's computer.

Question 11

A user reports that a laser printer is printing vertical blank lines on every page. The toner cartridge is new and properly installed. Which of the following should the technician check FIRST?

Accepted Answer

Clean the corona wire. Vertical blank lines on laser printer output typically indicate a problem with the primary corona wire or charge roller that is not evenly charging the drum. Cleaning the corona wire often resolves this issue. The fuser, if faulty, would cause smudging or ghosting rather than blank lines. Pickup rollers affect paper feeding, not print quality. A paper jam would prevent printing altogether or cause a paper jam error message.

Answer

Replace the fuser assembly

Answer

Replace the pickup rollers

Answer

Check for a paper jam

Question 12

A user's desktop computer does not boot and emits a series of long beeps. After checking the motherboard documentation, the technician confirms the beep code indicates a memory issue. Which of the following should the technician do FIRST?

Accepted Answer

Reseat the RAM modules. The beep code indicates a memory issue, and the most common cause is loose or improperly seated RAM modules. Reseating the RAM is the simplest, fastest, and least invasive first step to ensure proper contact between the memory module and the motherboard slot.

Answer

Replace the motherboard

Answer

Replace the power supply

Answer

Update the BIOS firmware

Question 13

A user reports that their desktop computer shuts down unexpectedly after about 30 minutes of use. The technician reads CPU temperature sensors in BIOS and sees the CPU idles at 45°C but quickly rises to 95°C under load before the system shuts down. The heatsink fan is spinning. Which of the following is the most likely cause?

Accepted Answer

The thermal paste between CPU and heatsink has dried out.. The CPU idles at 45°C but quickly spikes to 95°C under load, triggering a thermal shutdown. Since the heatsink fan is spinning, the most likely cause is degraded thermal paste, which has lost its ability to efficiently transfer heat from the CPU die to the heatsink, leading to rapid overheating even with active cooling.

Answer

The power supply is failing.

Answer

The RAM has a timing error.

Answer

The motherboard VRM is overheating.

Question 14

A network technician is troubleshooting a network laser printer that is intermittently dropping off the network. The printer has a static IP address of 192.168.1.50. The technician can sometimes ping the printer, but often the ping times out. The printer's network configuration page shows it is connected at 100 Mbps, half-duplex. The switch port to which the printer is connected supports up to 1000 Mbps and is set to auto-negotiate. Which of the following is the MOST likely cause of the intermittent connectivity?

Accepted Answer

The duplex settings are mismatched between the printer and the switch port.. The printer is manually set to half-duplex while the switch port is set to auto-negotiate. When a device is set to a fixed duplex (half) and the other end is set to auto-negotiate, the auto-negotiation process fails, causing the switch to default to half-duplex as well. However, because the printer is already hard-coded to half-duplex, the link may come up but with a duplex mismatch, leading to frequent collisions, retransmissions, and intermittent connectivity — explaining why pings sometimes succeed and sometimes time out.

Answer

The printer's network interface card (NIC) is faulty and needs to be replaced.

Answer

The switch port is configured for 1000 Mbps, but the printer only supports 100 Mbps, causing a speed mismatch.

Answer

The printer is configured with a static IP that conflicts with another device on the network.

Question 15

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

Transfer roller. The transfer roller is responsible for transferring toner from the imaging drum to the paper. If the transfer roller is damaged, contaminated, or worn, it can cause uneven charge distribution, leading to dark vertical streaks on the printed page. Since replacing the toner cartridge and imaging drum did not resolve the issue, the transfer roller is the next likely culprit.

Answer

Fuser assembly

Answer

Paper tray rollers

Answer

Laser scanner mirror

Question 16

A technician is troubleshooting a desktop computer that randomly freezes and then reboots. The technician runs a CPU stress test; after about 5 minutes, the system freezes and reboots. The CPU temperature during the test is monitored and never exceeds 75°C. The technician has run a full memory test (MemTest86) and a hard drive diagnostic (SMART check); both pass without errors. The power supply voltages are within specifications when measured with a multimeter at idle and under load. Which of the following is the MOST likely cause of the issue?

Accepted Answer

A failing power supply unit. The symptoms—random freezing and rebooting under CPU stress, with all other components (CPU temperature, memory, storage, and power supply voltages) passing diagnostics—point to a failing power supply unit (PSU). Even though the multimeter shows correct voltages at idle and under load, a PSU can fail intermittently under sustained high current draw, causing voltage ripple or transient drops that trigger a system reset. The CPU stress test specifically taxes the 12V rail, and a marginal PSU may not maintain stable output during extended high-load scenarios, leading to the observed behavior.

Answer

Insufficient voltage to the CPU due to motherboard VRM failure

Answer

A corrupted operating system driver

Answer

A failing system fan that spins intermittently

Question 17

A network laser printer is printing pages with garbled characters and random symbols. The technician prints a test page from the printer's control panel, which prints correctly. The technician then prints from a different computer on the same network, and the printout is also garbled. The printer driver has been reinstalled. Which of the following should the technician check NEXT?

Accepted Answer

Change the printer's emulation mode. The correct answer is C because the printer prints correctly from its own test page but produces garbled output from multiple network computers, indicating the issue is with how the print data is interpreted. Changing the printer's emulation mode (e.g., from PCL to PostScript or vice versa) resolves mismatches between the driver's page description language and the printer's interpreter, which is a common cause of garbled characters when the driver reinstall hasn't fixed the problem.

Answer

Replace the network cable

Answer

Update the printer firmware

Answer

Replace the imaging drum

Question 18

A technician is troubleshooting a desktop computer that powers on (fans spin, lights turn on) but the monitor displays 'No Signal'. The technician has already verified that the monitor works on another computer and has reseated the RAM and the discrete GPU. The motherboard has integrated graphics. Which of the following should the technician do NEXT?

Accepted Answer

Remove the discrete GPU and connect the monitor to the integrated graphics port.. Since the monitor works on another computer and the RAM/GPU have been reseated, the next logical step is to isolate whether the discrete GPU is faulty. By removing the discrete GPU and connecting the monitor to the integrated graphics port, the technician can test if the system boots with the CPU's built-in graphics. If it does, the discrete GPU is likely the problem; if not, the issue lies elsewhere (e.g., motherboard or CPU).

Answer

Replace the power supply unit (PSU) with a known-working unit.

Answer

Clear the CMOS by removing the onboard battery for 30 seconds.

Answer

Replace the RAM modules with known-working ones.

Question 19

A technician is troubleshooting a laser printer that produces pages with faint images. The toner cartridge is full and the imaging drum has been replaced recently. The technician prints a test page from the printer's control panel, which also appears faint. Which of the following components should the technician check or replace NEXT?

Accepted Answer

The primary charge roller (or corona wire).. The primary charge roller (or corona wire) applies a uniform electrostatic charge to the photosensitive drum. If it is worn, dirty, or failing, the drum cannot hold a proper charge, resulting in a faint image even with a full toner cartridge and a new drum. The test page being faint confirms the issue is in the image formation process, not the data path.

Answer

The fuser assembly.

Answer

The transfer roller.

Answer

The paper pickup rollers.

Question 20

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. The cable tester shows pins 4 and 5 are open, which in a T568A/B wiring scheme correspond to the blue pair (pair 3). This pair is used for voice in some standards, but in 10/100/1000BASE-T Ethernet, all four pairs are required for proper operation. Incorrect wiring on the wall jack (e.g., mis-termination or using a different standard like USOC) would cause intermittent connectivity because the link may train at a lower speed or fail when the pair is needed for data transmission.

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