Hardware and Network Troubleshooting practice questions

Tone generator and probe

Why wrong: A tone generator and probe are used to trace a specific cable among many, not to test termination quality.

Multimeter

Why wrong: A multimeter can check continuity but is less efficient for testing all eight wires and proper pairing in a twisted-pair cable.

Loopback plug

Why wrong: A loopback plug is used to test a network port by sending signals back to itself, not to test a standalone cable.

The laptop's wireless adapter is disabled in Device Manager.

Why wrong: If the adapter were disabled, the laptop would not see any Wi-Fi networks at all.

The Wi-Fi router is out of range.

Why wrong: If the laptop sees networks, it is within range of at least one router.

The laptop's Bluetooth is interfering with Wi-Fi.

Why wrong: Bluetooth and Wi-Fi can interfere, but this usually causes intermittent drops, not a complete inability to connect to any network.

The fiber cable is damaged

Why wrong: A damaged cable would cause the port to show 'down' or 'notconnect', not 'err-disabled', which is a software-disabled state.

A duplex mismatch exists between the switches

Why wrong: Duplex mismatch causes high error rates and poor performance but typically results in 'down' or 'flapping' ports, not 'err-disabled'.

The VLAN configuration is incorrect

Why wrong: Incorrect VLAN config would allow the port to be up but traffic may not pass; it would not cause err-disabled state.

ping -t

Why wrong: Ping with -t continuously tests reachability but does not show the path or identify where packets are lost.

netstat -r

Why wrong: Netstat -r displays the routing table, not the actual path packets take or where they are dropped.

pathping

Why wrong: Pathping does trace the route and calculate packet loss per hop, but it takes longer to complete and is less commonly used for quick troubleshooting than tracert.

DHCP

Why wrong: DHCP assigns IPs locally but doesn't create secure tunnels.

DNS

Why wrong: DNS resolves names but doesn't provide encryption or tunneling.

NAT

Why wrong: NAT translates IPs but doesn't provide secure connectivity across the internet.

Infrastructure mode WLAN; configure a laptop as a software access point.

Why wrong: Infrastructure mode requires an AP, but the scenario specifies no central device; a software AP still creates a central point.

PAN network using Bluetooth; all laptops pair via Bluetooth.

Why wrong: Bluetooth PANs are for personal devices and have limited range and speed, not suitable for multiple laptops sharing files.

Mesh network; each laptop acts as a node forwarding traffic.

Why wrong: A mesh network requires each laptop to forward traffic for others, but the scenario demands direct file sharing without any central access point or router. This fails because mesh nodes still rely on routing protocols and multi-hop forwarding, which introduces complexity and dependency on intermediary devices. It is tempting because mesh networks are designed for decentralised, ad-hoc connectivity in environments lacking infrastructure, such as disaster recovery sites, where they would be the correct choice for resilient, self-healing communication.

Use a USB-C to Ethernet adapter and charge the tablet wirelessly.

Why wrong: Wireless charging is inefficient and may not provide continuous power; also, the tablet may not support it.

Use a Wi-Fi connection and a standard USB-C charger.

Why wrong: This provides power but not wired network reliability; the scenario specifically requires wired network.

Connect the tablet to the network via Bluetooth tethering to a phone.

Why wrong: Bluetooth tethering is slow and unreliable for digital signage; also, it does not provide power.

The fuser assembly

Why wrong: A failing fuser usually causes smudging or paper jams, not grinding noises and vertical streaks.

The pickup rollers

Why wrong: Bad pickup rollers cause paper jams or misfeeds, not print quality issues or grinding.

The transfer roller

Why wrong: A faulty transfer roller causes uneven toner transfer, but typically no grinding noise.

Enable Link Aggregation Control Protocol (LACP) on the server connections.

Why wrong: LACP combines multiple links for increased bandwidth and redundancy, but it does not prevent loops on its own. STP is still needed to manage redundant paths.

Use a hub instead of a switch for the core connection.

Why wrong: Hubs do not prevent loops and would cause collisions and performance issues. They are not suitable for data center networks.

Configure all switch ports as access ports.

Why wrong: Access ports are for end devices and do not affect loop prevention. Redundant links would still cause loops without STP.

255.255.255.0

Why wrong: A /24 subnet provides 254 usable hosts, which is far more than needed for 50 devices and would waste IP addresses.

255.255.255.224

Why wrong: A /27 subnet provides 30 usable hosts, which is not enough for 50 devices.

255.255.255.240

Why wrong: A /28 subnet provides 14 usable hosts, which is far too few for 50 devices.

DHCP

Why wrong: DHCP assigns IP addresses but does not manage traffic prioritization.

DNS

Why wrong: DNS resolves domain names and does not affect traffic prioritization.

VPN

Why wrong: VPN adds encryption overhead and can increase latency, not reduce it for VoIP.

The replacement drive is of a different RPM.

Why wrong: While RPM can affect speed, the primary bottleneck is the parity calculation and drive capacity, not a slight RPM difference.

The RAID controller is faulty.

Why wrong: A faulty controller would likely cause errors or crashes, not just a slow rebuild.

The array is performing background consistency checks.

Why wrong: Consistency checks are separate from rebuilds and are not automatically triggered by a drive replacement.

The charging port is loose.

Why wrong: A loose port would cause intermittent charging or no power at all, not a consistent 'not charging' status.

The power management driver is outdated.

Why wrong: Driver issues can cause charging problems, but a hardware failure is more likely given the battery's age and symptoms.

The CMOS battery is dead.

Why wrong: A dead CMOS battery affects system clock and BIOS settings, not main battery charging.

The fan is running at low speed due to a faulty fan controller.

Why wrong: The fan is spinning, so the controller is likely fine; the issue is thermal transfer, not fan speed.

The CPU is faulty and needs replacement.

Why wrong: A faulty CPU is possible but less likely than a thermal paste issue; overheating is a common symptom of poor thermal contact.

The BIOS is set to an aggressive power-saving mode.

Why wrong: Power-saving modes reduce performance, not cause overheating; they would lower temperatures.

Install a screen protector on each tablet.

Why wrong: While protective, this is not essential for kiosk mode configuration.

Remove the SIM card from each tablet.

Why wrong: SIM removal is unnecessary unless cellular access is restricted; kiosk mode can be set with or without it.

Replace the stock ROM with a custom firmware.

Why wrong: Custom firmware voids warranty and is not standard practice for enterprise deployment; kiosk mode uses built-in OS features.

Calibrate the battery by fully draining and recharging.

Why wrong: Calibration helps with inaccurate charge reporting, not with actual capacity loss.

Update the operating system to the latest version.

Why wrong: OS updates may improve efficiency but won't fix hardware degradation of the battery.

Disable all background apps and notifications.

Why wrong: This is a software workaround, not a hardware servicing solution for a degraded battery.

The laptop's IP address configuration

Why wrong: IP configuration issues would prevent network access, but the laptop can connect to the hotspot, suggesting DHCP is working.

The laptop's firewall settings

Why wrong: Firewall settings might block certain traffic, but the first step is to ensure the hotspot itself has internet access.

The smartphone's Wi-Fi is turned on

Why wrong: Wi-Fi on the phone is used for the hotspot, but it's already broadcasting; the issue is internet access, not connectivity.

The phone's battery level

Why wrong: Battery level does not affect NFC functionality as long as the phone is on.

The payment terminal's internet connection

Why wrong: NFC transactions can work offline; the terminal's internet is for authorization, not detection.

The phone's default payment app settings

Why wrong: App settings affect which card is used, but the terminal not detecting the phone at all points to a hardware or alignment issue.

Uninstall the mouse driver and reboot.

Why wrong: This would remove the mouse driver entirely, requiring reinstallation and potentially affecting other devices.

Change the mouse's Bluetooth pairing to a different channel.

Why wrong: Bluetooth channels are managed automatically; manual channel selection is not a standard user setting.

Update the laptop's BIOS to the latest version.

Why wrong: BIOS updates can fix hardware compatibility, but this is a driver/software issue, not a BIOS problem.

Ensure the tablet's Bluetooth is turned on.

Why wrong: The tablet already connects to headphones, so Bluetooth is on. This is not the issue.

Update the tablet's operating system.

Why wrong: An OS update is unlikely to fix a specific pairing issue with one device, especially when other Bluetooth devices work.

Reset the tablet's network settings.

Why wrong: Resetting the tablet’s network settings clears saved Wi-Fi, Bluetooth pairings, and cellular APN data, but the issue is that Bluetooth keyboards and headphones use the same Bluetooth radio and stack. Since headphones already connect, the radio and stack are functional; the problem likely lies in the keyboard’s pairing profile or a driver-level incompatibility. This option is tempting because network resets often resolve connectivity failures, and it would be correct if the tablet could not connect to any Bluetooth device, indicating a corrupted Bluetooth cache or radio configuration.