CompTIA A+ Core 1 — All Questions

Which memory technology is most commonly used as the main system RAM in a modern desktop computer?

• a.GDDR video memory
• b.DDR SDRAM DIMMs✓
• c.NAND flash chips
• d.EEPROM

Modern desktops use DDR SDRAM installed as DIMM modules for main system memory. NAND flash is used for SSDs, GDDR is dedicated video memory on graphics cards, and EEPROM stores small amounts of firmware data.

A technician wants dual-channel memory performance. What is the correct way to install two matching DIMMs?

• a.Populate the matching color-coded slots specified by the board✓
• b.Install one DDR4 and one DDR5 module
• c.Stack them in the first two physical slots only
• d.Place both in adjacent slots regardless of color

Dual-channel mode requires identical modules placed in the color-coded slot pairs the motherboard designates, usually slots 1 and 3 or 2 and 4. Mixing memory generations is impossible because the slots are keyed differently, and simply using adjacent slots may not enable dual channel.

Which storage interface offers the highest sequential throughput for a consumer SSD?

• a.NVMe over PCIe✓
• b.PATA/IDE
• c.SATA III
• d.USB 2.0

NVMe drives communicate over the PCIe bus and greatly exceed the roughly 600 MB/s ceiling of SATA III. USB 2.0 and legacy PATA are far slower and are not used for high-performance internal storage.

What physical form factor is typical for an NVMe solid-state drive installed directly on a motherboard?

• a.PCIe x16 graphics slot
• b.2.5-inch drive bay
• c.5.25-inch bay
• d.M.2 slot✓

Consumer NVMe SSDs commonly use the M.2 gumstick form factor that plugs into a dedicated M.2 slot on the board. The 2.5-inch bay is for SATA SSDs and laptops, while the x16 slot is intended for graphics cards.

A power supply is rated 80 PLUS Gold. What does this rating describe?

• a.The number of PCIe connectors
• b.Physical size of the unit
• c.Maximum wattage output
• d.Energy efficiency at typical loads✓

The 80 PLUS certification tiers (Bronze, Gold, Platinum, etc.) describe how efficiently a PSU converts AC to DC at various load levels. It does not indicate the wattage, connector count, or physical dimensions of the unit.

Which connector supplies dedicated power to a high-end graphics card?

• a.SATA power connector
• b.24-pin ATX
• c.6/8-pin PCIe power connector✓
• d.4-pin Molex to the CPU

Discrete GPUs draw supplemental power through 6-pin or 8-pin PCIe power connectors from the PSU. The 24-pin feeds the motherboard, SATA power feeds drives, and the CPU uses a separate 4/8-pin EPS connector.

What is the primary purpose of thermal paste between a CPU and its heat sink?

• a.To glue the heat sink permanently
• b.To insulate the CPU electrically
• c.To prevent static discharge
• d.To fill microscopic gaps and improve heat transfer✓

Thermal paste fills the tiny air gaps between the CPU integrated heat spreader and the cooler base, improving thermal conduction. It is not an adhesive, an electrical insulator, or an anti-static measure.

Which expansion slot is used by a modern discrete graphics card?

• a.AGP
• b.PCI 32-bit
• c.PCIe x16✓
• d.ISA

Current graphics cards use the PCI Express x16 slot for maximum bandwidth. PCI, AGP, and ISA are legacy interfaces no longer used for new GPUs.

A motherboard's CMOS settings and clock reset every time the PC is unplugged. What is the most likely cause?

• a.Failed CPU
• b.Bad RAM
• c.Depleted CMOS battery✓
• d.Corrupt operating system

The coin-cell CMOS battery (typically a CR2032) maintains BIOS/UEFI settings and the real-time clock when power is removed. When it dies, settings and the clock reset on every power loss.

Which RAID level mirrors data across two drives for redundancy without striping?

• a.RAID 0
• b.RAID 1✓
• c.RAID 10
• d.RAID 5

RAID 1 writes identical copies of data to two drives, providing fault tolerance if one drive fails. RAID 0 stripes without redundancy, RAID 5 uses striping with parity, and RAID 10 combines mirroring and striping.

How many drives are minimally required to build a RAID 5 array?

• a.Four
• b.One
• c.Three✓
• d.Two

RAID 5 distributes parity across all members and needs a minimum of three drives. It can survive the loss of a single drive by rebuilding from parity information.

Which display connector can carry both high-resolution video and audio over a single cable and is common on modern GPUs?

• a.PS/2
• b.VGA
• c.DVI-D
• d.DisplayPort✓

DisplayPort carries digital video and audio and supports high resolutions and refresh rates. VGA is analog video only, DVI-D carries video but not audio, and PS/2 is a keyboard/mouse connector.

What does ECC memory provide that standard memory does not?

• a.Lower power draw
• b.Built-in encryption
• c.Detection and correction of single-bit errors✓
• d.Faster clock speeds

ECC (error-correcting code) memory can detect and correct single-bit errors, which is valuable in servers and workstations. It does not inherently run faster, use less power, or encrypt data.

A technician needs to connect four SATA hard drives but the case lacks power connectors. Which cable adapts available power?

• a.USB-to-Ethernet adapter
• b.Molex-to-SATA power adapter✓
• c.DVI-to-VGA adapter
• d.HDMI splitter

A Molex-to-SATA power adapter converts a legacy 4-pin Molex lead into a SATA power connector for drives. The other adapters handle video or network signals, not drive power.

Which CPU feature allows a single physical core to handle two threads simultaneously?

• a.Simultaneous multithreading (Hyper-Threading)✓
• b.Integrated graphics
• c.Thermal throttling
• d.Overclocking

Simultaneous multithreading, marketed by Intel as Hyper-Threading, lets one core process two instruction threads to improve utilization. Overclocking raises clock speed, throttling reduces it for heat, and integrated graphics is a separate GPU feature.

What is the standard number of pins on the main ATX motherboard power connector?

• a.4 pins
• b.20 pins only
• c.8 pins
• d.24 pins✓

The modern main ATX power connector has 24 pins (a 20-pin base plus a 4-pin extension). The separate CPU EPS connector uses 4 or 8 pins.

Which type of cooling uses a pump, radiator, and liquid to move heat away from the CPU?

• a.Case fan only
• b.Thermal pad
• c.Passive heat sink
• d.Closed-loop liquid cooler (AIO)✓

An all-in-one (AIO) closed-loop liquid cooler circulates coolant through a CPU block to a radiator with fans. A passive heat sink, single case fan, or thermal pad rely on simpler conduction and airflow.

A user reports the PC powers on but there is no display and a repeating beep code sounds. What should the technician consult?

• a.The printer manual
• b.The motherboard/BIOS beep code documentation✓
• c.The Wi-Fi router settings
• d.The event log in Windows

POST beep codes are defined by the BIOS/motherboard vendor and point to hardware faults such as RAM or GPU problems. Because there is no display and the OS has not loaded, Windows logs are unavailable.

Which connector standard is commonly used for internal case front-panel USB 3.x headers?

• a.3.5mm TRS
• b.19/20-pin USB 3.0 header✓
• c.RJ45
• d.PS/2 mini-DIN

Front-panel USB 3.x ports connect to the motherboard through a keyed 19/20-pin internal header. RJ45 is for Ethernet, 3.5mm is audio, and PS/2 is a legacy input connector.

What is the main advantage of a solid-state drive over a traditional hard disk drive?

• a.Uses magnetic platters for redundancy
• b.Larger maximum capacity at lower cost
• c.No moving parts, faster access, and shock resistance✓
• d.Requires no data connection

SSDs store data in flash with no moving parts, giving faster access times and better durability against shock. HDDs still lead on cost per terabyte, but they rely on spinning magnetic platters.

Which component temporarily stores data the CPU is actively using and loses its contents when powered off?

• a.Optical disc
• b.BIOS ROM
• c.Hard drive
• d.System RAM✓

System RAM is volatile memory that holds active program data and is cleared when power is removed. Hard drives and optical discs are non-volatile storage, and BIOS ROM retains firmware.

A technician is asked to install a second GPU for more video ports. Which factor must be verified first?

• a.Number of USB drives
• b.Available PCIe slots and adequate PSU wattage/connectors✓
• c.Monitor cable color
• d.Keyboard layout

Adding a GPU requires a free PCIe x16 slot and a power supply with enough wattage and the correct PCIe power connectors. Peripheral details like cable color or USB drives are irrelevant to installation feasibility.

Which unit describes the rotational speed of a mechanical hard drive that affects its performance?

• a.Watts
• b.Gbps
• c.RPM✓
• d.MHz

Mechanical HDD performance is influenced by platter rotational speed measured in revolutions per minute (e.g., 5400 or 7200 RPM). MHz measures clock frequency, Gbps measures data rate, and watts measure power.

What is the correct anti-static precaution when handling internal PC components?

• a.Wear rubber gloves and touch nothing metal
• b.Work on a carpeted floor barefoot
• c.Rub the component to discharge it
• d.Use an anti-static wrist strap connected to a grounding point✓

An ESD wrist strap bonded to a proper ground equalizes potential and safely dissipates static that could damage components. Carpet increases static, rubbing generates it, and simply wearing rubber gloves does not ground you.

Which TCP port is used by HTTPS web traffic by default?

• a.25
• b.443✓
• c.21
• d.80

HTTPS uses TCP port 443 for encrypted web traffic. Port 80 is plain HTTP, port 21 is FTP control, and port 25 is SMTP email.

What port does standard unencrypted HTTP use?

• a.3389
• b.80✓
• c.53
• d.443

HTTP serves web pages over TCP port 80. Port 443 is HTTPS, 53 is DNS, and 3389 is Remote Desktop Protocol.

Which protocol translates human-readable domain names into IP addresses?

• a.SNMP
• b.DNS✓
• c.SMTP
• d.DHCP

DNS resolves names like example.com into IP addresses. DHCP assigns addresses, SMTP sends email, and SNMP monitors network devices.

Which service automatically assigns IP addresses, subnet masks, and gateways to clients?

• a.DNS
• b.DHCP✓
• c.FTP
• d.LDAP

DHCP leases IP configuration to clients automatically. DNS handles name resolution, FTP transfers files, and LDAP provides directory services.

Which Wi-Fi standard, also known as Wi-Fi 6, operates in both 2.4 GHz and 5 GHz bands with improved efficiency?

• a.802.11g
• b.802.11n
• c.802.11ax✓
• d.802.11ac

802.11ax (Wi-Fi 6) improves efficiency and capacity and works in both 2.4 GHz and 5 GHz. 802.11ac is 5 GHz only, while 802.11n and 802.11g are older standards.

Which class of IPv4 address is 192.168.1.0/24 considered?

• a.Public routable
• b.Loopback
• c.Private (RFC 1918)✓
• d.APIPA

The 192.168.0.0/16 range is private per RFC 1918 and is not routable on the public internet. Loopback is 127.0.0.0/8, and APIPA uses 169.254.0.0/16.

A client shows an IP address in the 169.254.x.x range. What does this indicate?

• a.A static public IP
• b.A successful DHCP lease
• c.An IPv6 link-local address
• d.APIPA — the client failed to reach a DHCP server✓

An address in 169.254.0.0/16 is APIPA, which a Windows host self-assigns when no DHCP server responds. It signals a DHCP problem rather than a normal lease.

Which port is used by the Remote Desktop Protocol (RDP)?

• a.23
• b.161
• c.22
• d.3389✓

RDP listens on TCP port 3389. Port 22 is SSH, port 23 is Telnet, and 161 is SNMP.

Which protocol provides secure encrypted command-line access to a remote device?

• a.HTTP
• b.FTP
• c.Telnet
• d.SSH✓

SSH encrypts remote shell sessions on port 22. Telnet, FTP, and HTTP all send data, including credentials, in clear text by default.

What is the primary function of a router in a network?

• a.Amplify Wi-Fi signal only
• b.Forward packets between different networks✓
• c.Store shared files
• d.Provide power over Ethernet

A router forwards packets between separate networks, such as a home LAN and the internet, using IP addressing. Signal boosting, PoE, and file storage are handled by other devices.

Which cable type is required for 10 Gigabit Ethernet over reasonable copper distances?

• a.Cat 3
• b.RG-6 coax
• c.Cat 6a✓
• d.Cat 5

Cat 6a supports 10 Gbps over 100 meters. Cat 5 and Cat 3 cannot reliably carry 10 Gbps, and RG-6 is coaxial cable used for video/cable modems.

Which device operates primarily at Layer 2 and forwards frames based on MAC addresses?

• a.Hub
• b.Router
• c.Switch✓
• d.Modem

A switch learns MAC addresses and forwards frames only to the correct port at Layer 2. A hub blindly repeats to all ports, a router works at Layer 3, and a modem modulates signals for the ISP link.

What does NAT allow a home network to do?

• a.Encrypt all traffic automatically
• b.Assign DNS names
• c.Increase Wi-Fi range
• d.Share one public IP among many private devices✓

Network Address Translation lets multiple internal devices share a single public IP address. It is not an encryption, range-extension, or naming service.

Which protocol and port combination is used to send email between mail servers?

• a.SMTP on 25✓
• b.IMAP on 143
• c.DNS on 53
• d.POP3 on 110

SMTP on TCP port 25 transfers email between servers. POP3 (110) and IMAP (143) are used by clients to retrieve mail, and DNS resolves names.

A subnet mask of 255.255.255.0 corresponds to which CIDR notation?

• a./8
• b./24✓
• c./16
• d./32

255.255.255.0 sets the first 24 bits as the network portion, written as /24. /16 is 255.255.0.0, /8 is 255.0.0.0, and /32 is a single host.

Which wireless frequency band generally offers longer range but lower maximum speed?

• a.5 GHz
• b.2.4 GHz✓
• c.60 GHz
• d.6 GHz

The 2.4 GHz band penetrates walls better and reaches farther but supports lower throughput and has more interference. Higher bands like 5 GHz and 6 GHz offer more speed over shorter distances.

Which connector terminates a twisted-pair Ethernet cable?

• a.SC
• b.RJ11
• c.BNC
• d.RJ45✓

Ethernet twisted-pair cables use 8-position RJ45 connectors. RJ11 is for telephone lines, BNC is coax, and SC is a fiber-optic connector.

What is the purpose of a default gateway in IP configuration?

• a.Assign IP leases
• b.Resolve domain names
• c.Filter spam
• d.Route traffic destined for other networks✓

The default gateway is the router address a host sends traffic to when the destination is on another network. DNS resolves names and DHCP assigns leases.

Which command-line tool displays a device's current IP configuration on Windows?

• a.tracert
• b.ipconfig✓
• c.nslookup
• d.ping

ipconfig shows the local IP address, subnet mask, and gateway on Windows. ping tests reachability, tracert maps the route, and nslookup queries DNS.

Which protocol is used to synchronize the clocks of devices across a network?

• a.SNMP
• b.SMTP
• c.NTP✓
• d.DHCP

The Network Time Protocol (NTP) keeps device clocks synchronized, typically over UDP port 123. SNMP monitors devices, SMTP sends email, and DHCP assigns IP configuration.

Which storage type is used in most modern laptops due to durability and speed?

• a.Optical drive
• b.Solid-state drive (M.2 or SATA)✓
• c.Tape drive
• d.5400 RPM hard drive

Modern laptops favor SSDs for their speed, low power draw, and resistance to shock from movement. Spinning drives, optical, and tape are largely obsolete in current portable designs.

A laptop battery no longer holds a charge and is swollen. What is the correct action?

• a.Keep using it until fully dead
• b.Freeze it overnight
• c.Puncture it to release gas
• d.Safely replace the battery and dispose of it properly✓

A swollen lithium-ion battery is a safety hazard and must be replaced and recycled through proper channels. Continuing to use, puncturing, or freezing it risks fire or rupture.

Which technology lets a smartphone make contactless payments when tapped at a terminal?

• a.GPS
• b.Infrared
• c.Bluetooth
• d.NFC✓

Near Field Communication (NFC) enables tap-to-pay over very short distances. Bluetooth pairs peripherals, GPS provides location, and infrared is a legacy line-of-sight link.

What does a laptop's inverter historically provide power to on older LCD screens?

• a.The webcam
• b.The trackpad
• c.The CCFL backlight✓
• d.The keyboard backlight

On older laptops the inverter supplied high voltage to the cold-cathode fluorescent (CCFL) backlight. Modern LED-backlit panels no longer need an inverter.

Which connector has become the common standard for charging and data on modern Android phones and many laptops?

• a.Micro-USB
• b.Mini-USB
• c.Lightning
• d.USB-C✓

USB-C is a reversible connector widely adopted for charging and data on Android devices and laptops. Micro-USB and Mini-USB are older, and Lightning is Apple-specific.

A user wants to sync a wireless headset to a phone. Which technology is used?

• a.Ethernet
• b.HDMI
• c.Bluetooth pairing✓
• d.NFC only

Bluetooth is used to pair and connect wireless audio devices to phones. NFC may initiate pairing on some devices but the audio link runs over Bluetooth; Ethernet and HDMI are wired.

Which component in a laptop allows it to connect to wireless networks and is often a replaceable M.2 card?

• a.CMOS battery
• b.Wi-Fi/WLAN card✓
• c.Northbridge
• d.Optical drive

The WLAN (Wi-Fi) card, frequently an M.2 module, provides wireless connectivity and can be serviced or upgraded. The CMOS battery, chipset, and optical drive serve different roles.

What is the benefit of mobile device MDM (mobile device management) in an enterprise?

• a.Improves battery chemistry
• b.Centralizes policy, security, and remote wipe control✓
• c.Adds physical ports
• d.Increases screen resolution

MDM lets IT enforce security policies, push configurations, and remotely wipe lost or stolen devices from a central console. It has no effect on hardware such as battery, screen, or ports.

A tablet's screen does not rotate when turned. Which sensor is most likely involved?

• a.Proximity sensor
• b.Fingerprint reader
• c.Accelerometer/gyroscope✓
• d.Ambient light sensor

Screen auto-rotation depends on the accelerometer and gyroscope detecting orientation. The proximity sensor handles call screen-off, the light sensor adjusts brightness, and the fingerprint reader handles authentication.

Which feature encrypts the data stored on a lost smartphone so it cannot be easily read?

• a.Screen timeout
• b.Full-device encryption with a passcode✓
• c.Airplane mode
• d.Do Not Disturb

Full-device encryption tied to a passcode protects stored data if the phone is lost or stolen. Airplane mode, Do Not Disturb, and screen timeout do not protect data at rest.

A laptop only charges intermittently and the port feels loose. What is the most likely fix?

• a.Reset the router
• b.Repair or replace the DC jack / charging port✓
• c.Replace the operating system
• d.Increase screen brightness

A loose, intermittently charging port usually indicates a worn or damaged DC jack that needs repair or replacement. Software, display, and network changes would not resolve a physical power connection fault.

Which of the following is a common way to expand storage on many Android phones and tablets?

• a.Adding a microSD card✓
• b.Adding a DIMM
• c.Attaching a PCIe card
• d.Installing a second CPU

Many Android devices accept a microSD card to expand storage. Phones do not accept desktop-style CPUs, PCIe cards, or DIMMs.

A user reports very short battery life after a recent update. What is a reasonable first troubleshooting step?

• a.Replace the motherboard
• b.Check battery usage stats and background apps in settings✓
• c.Swap the SIM card
• d.Reinstall the display driver

Reviewing the battery usage screen reveals which apps or processes are draining power, a logical first step after an update. Replacing hardware or swapping the SIM is premature and unrelated.

Which port on a modern laptop can carry video, data, and power over a single reversible connector using the appropriate standard?

• a.VGA
• b.RJ45
• c.PS/2
• d.USB-C with Thunderbolt/DP alt mode✓

A USB-C port supporting Thunderbolt or DisplayPort alt mode can deliver video, data, and power simultaneously. VGA carries analog video only, RJ45 is networking, and PS/2 is legacy input.

What software layer creates and manages virtual machines on a host?

• a.Device driver
• b.Bootloader
• c.Hypervisor✓
• d.Firmware

A hypervisor abstracts physical hardware and allocates it to virtual machines. Firmware, drivers, and bootloaders serve other low-level roles and do not manage VMs.

Which type of hypervisor runs directly on the physical hardware without a host OS?

• a.Type 1 (bare-metal)✓
• b.Type 2 (hosted)
• c.Container engine
• d.Emulator

A Type 1 bare-metal hypervisor installs directly on hardware for maximum performance, as in enterprise virtualization. A Type 2 hypervisor runs on top of an existing OS.

In cloud computing, what does IaaS provide?

• a.Only a development platform
• b.Physical office space
• c.Virtualized compute, storage, and networking infrastructure✓
• d.Finished applications only

Infrastructure as a Service delivers virtual machines, storage, and networking that customers manage themselves. SaaS delivers finished apps and PaaS provides a development platform.

Which cloud model delivers ready-to-use applications over the internet, such as web-based email?

• a.On-premises
• b.PaaS
• c.IaaS
• d.SaaS✓

Software as a Service provides fully managed applications accessed through a browser, like webmail or online office suites. IaaS and PaaS provide lower-level infrastructure and platforms.

What is a key benefit of cloud elasticity?

• a.Resources scale up or down automatically with demand✓
• b.No internet requirement
• c.Fixed capacity regardless of demand
• d.Permanent local storage

Elasticity lets cloud resources expand or contract automatically to match workload demand, controlling cost and performance. Fixed capacity is the opposite of elasticity.

Which characteristic distinguishes a public cloud from a private cloud?

• a.It runs only on a single laptop
• b.It can never scale
• c.It is hosted by a third-party provider and shared among tenants✓
• d.It has no virtualization

A public cloud is operated by a provider and shares multi-tenant infrastructure among many customers. A private cloud is dedicated to a single organization.

What technology packages an application with its dependencies to run consistently across environments, sharing the host OS kernel?

• a.Disk image backup
• b.Full virtual machine
• c.Container✓
• d.BIOS update

Containers bundle an app and its dependencies and share the host kernel, making them lightweight and portable. A full VM includes an entire guest OS and is heavier.

A VM needs more processing power. Which resource does the administrator typically adjust in the hypervisor?

• a.The number of physical monitors
• b.The office thermostat
• c.The keyboard layout
• d.Allocated vCPUs and RAM✓

Administrators tune a VM's assigned virtual CPUs and memory in the hypervisor to change its performance. Physical peripherals and environmental settings are unrelated to VM resource allocation.

What is a common purpose of virtualization in a test lab?

• a.To remove the need for backups
• b.To eliminate all networking
• c.To run multiple isolated OS environments on one machine✓
• d.To increase monitor size

Virtualization lets a single physical machine host multiple isolated operating systems for testing and development. It does not remove networking or the need for backups.

Which cloud deployment combines on-premises resources with public cloud services working together?

• a.Air-gapped network
• b.Hybrid cloud✓
• c.Community cloud
• d.Bare-metal only

A hybrid cloud integrates private/on-premises infrastructure with public cloud so workloads can move between them. A community cloud is shared among related organizations, unlike a hybrid mix.

What does 'measured service' mean in cloud computing?

• a.Usage is metered so customers pay for what they consume✓
• b.Resources are unlimited and free
• c.Service quality is guessed
• d.Only one user is allowed

Measured service means the provider meters resource usage so billing reflects actual consumption, a core cloud characteristic. It is the basis of pay-as-you-go pricing.

Before creating multiple VMs on a host, which physical resource is most important to verify is sufficient?

• a.Color of the case
• b.Available CPU cores, RAM, and storage on the host✓
• c.Number of USB ports
• d.Brand of the mouse

The host must have enough CPU, memory, and storage to allocate across all planned VMs without overcommitting to the point of poor performance. Cosmetic and peripheral details are irrelevant.

What is the correct first step in the CompTIA troubleshooting methodology?

• a.Implement the fix immediately
• b.Identify the problem✓
• c.Reboot everything
• d.Document the outcome

The methodology begins with identifying the problem by gathering information and questioning the user. Establishing a theory, testing, fixing, and documenting come later in the sequence.

After identifying a problem, what is the next step in the methodology?

• a.Verify full functionality
• b.Escalate to a vendor
• c.Document findings
• d.Establish a theory of probable cause✓

Once the problem is identified, the technician establishes a theory of probable cause. Testing the theory follows, and documentation is the final step.

What should a technician do immediately after implementing a fix?

• a.Verify full system functionality and implement preventive measures✓
• b.Close the ticket without checking
• c.Ignore the user
• d.Delete the logs

After the fix, the technician verifies full functionality and, where applicable, applies preventive measures to avoid recurrence. Only then is documentation completed and the ticket closed.

What is the final step of the troubleshooting methodology?

• a.Test the theory
• b.Identify the problem
• c.Establish a theory
• d.Document findings, actions, and outcomes✓

The last step is documenting the findings, actions taken, and outcomes so the knowledge is preserved. The earlier steps involve identifying, theorizing, testing, and fixing.

A desktop shows no power at all — no lights, no fans. What should be checked first?

• a.Update the GPU driver
• b.Power source, cable, and PSU switch✓
• c.Replace the RAM
• d.Reinstall the OS

With zero signs of power, begin with the simplest external causes: the outlet, power cable, and the PSU on/off switch and voltage setting. Software and internal component swaps come only after power is confirmed.

A PC powers on and fans spin, but there is no video and no beep. What is a reasonable early check?

• a.Change the Wi-Fi password
• b.Reseat RAM and GPU, verify monitor input✓
• c.Update antivirus
• d.Reformat the hard drive

No POST and no beep often points to seating issues with RAM or the GPU, or the monitor being on the wrong input. Reformatting, network, or antivirus changes do not address a no-POST condition.

A user cannot reach any website, but other devices on the same network can. What should be checked first on that PC?

• a.The ISP's core routers
• b.The website's server
• c.The DNS root servers
• d.The PC's IP configuration and cable/Wi-Fi connection✓

Because other devices work, the issue is likely local: check the affected PC's IP settings and its physical or wireless connection. The ISP and remote servers are unlikely causes when only one device fails.

A computer's clock and BIOS settings reset on each boot. What component should be replaced?

• a.Hard drive
• b.Sound card
• c.CMOS battery✓
• d.Power supply

Losing time and BIOS settings each boot indicates a dead CMOS battery that can no longer retain configuration. The other components would produce different symptoms.

A laptop displays 'No bootable device' after working fine yesterday. What is a good first step?

• a.Reinstall Wi-Fi drivers
• b.Replace the screen
• c.Check boot order and verify the drive is detected in BIOS/UEFI✓
• d.Increase RAM

This message suggests the firmware cannot find a boot drive, so verify the boot order and whether the drive is detected in BIOS/UEFI. A missing drive there points to a loose or failing disk.

A printer prints faint, streaky output on a laser printer. Which component is the most likely cause?

• a.Motherboard
• b.Network cable
• c.Toner cartridge low or failing drum✓
• d.RAM module

Faint or streaky laser output typically stems from low toner or a worn imaging drum. Network and system-board components would not cause print-quality defects.

A system randomly reboots under heavy load. Which cause should be investigated?

• a.Overheating or inadequate/failing power supply✓
• b.Keyboard layout
• c.Browser cache
• d.Wallpaper resolution

Random reboots under load commonly result from overheating (dust, failing fans, dried thermal paste) or a power supply that cannot sustain the load. Cosmetic software settings do not cause reboots.

A user reports intermittent Wi-Fi drops only in a back room. What is the most likely cause?

• a.Bad monitor
• b.Weak signal from distance/interference✓
• c.Corrupt BIOS
• d.Faulty CPU

Connectivity problems limited to a distant room point to weak signal from range or interference rather than a hardware fault in the PC. Relocating the access point or adding an extender often helps.

When testing a theory that RAM is faulty, which action best confirms it?

• a.Change the desktop theme
• b.Run a memory diagnostic or swap in known-good RAM✓
• c.Reinstall the printer driver
• d.Replace the entire motherboard

Running a memory test or substituting known-good modules directly confirms or rules out faulty RAM. Wholesale board replacement is excessive before isolating the cause.

A monitor displays a distorted image with wrong colors. What should be checked first?

• a.The video cable and connection, then GPU driver✓
• b.The network switch
• c.The hard drive capacity
• d.The keyboard battery

Color and image distortion usually trace to a loose or damaged video cable or a driver problem, so check those first. Storage and network components do not affect display color.

A newly built PC will not POST. Which minimal configuration helps isolate the fault?

• a.Disconnect the PSU entirely
• b.Add every drive and card at once
• c.Boot with only CPU, one RAM stick, and integrated video✓
• d.Remove the CPU

Booting with a minimal configuration (CPU, one stick of RAM, and onboard or a single GPU) helps isolate which component prevents POST. Removing the CPU or PSU makes booting impossible.

A user's files are inaccessible and the drive makes clicking noises. What is the priority?

• a.Continue using the drive normally
• b.Stop using it and attempt data recovery/backup✓
• c.Overwrite the drive
• d.Defragment immediately

Clicking noises indicate imminent mechanical HDD failure, so the priority is to stop stressing the drive and recover data from a backup or via recovery tools. Continued use, defragmenting, or overwriting risks total loss.

A laptop overheats and shuts down during video calls. What is a likely maintenance fix?

• a.Clean dust from vents/fan and check thermal paste✓
• b.Add a second monitor
• c.Disable the microphone
• d.Increase display brightness

Thermal shutdowns are commonly caused by dust-clogged vents, a failing fan, or degraded thermal paste, all addressable by cleaning and reapplication. Display or peripheral changes do not resolve overheating.

A group of users cannot access a shared network printer, but local USB printing works. What should be investigated?

• a.Each user's monitor
• b.The building's HVAC
• c.The print server or network path to the printer✓
• d.The users' keyboards

When many users lose network printing but local printing works, the shared print server or the network path to the printer is the likely culprit. Individual peripherals are not the common cause.

A PC boots to a black screen with a blinking cursor and no OS load. What is a reasonable check?

• a.The keyboard color
• b.The speaker volume
• c.Boot device order and MBR/boot files integrity✓
• d.The mouse DPI

A blinking cursor with no OS often means the firmware cannot find valid boot files, so verify boot order and repair the bootloader/MBR. Input and audio settings are unrelated.

Which tool measures voltage output from a power supply's connectors?

• a.Cable tester
• b.Loopback plug
• c.Toner probe
• d.Multimeter or PSU tester✓

A multimeter or dedicated PSU tester verifies that each rail outputs correct voltage. A cable tester checks wiring continuity, a loopback tests ports, and a toner probe traces cables.

A network cable run seems dead. Which tool verifies the wiring is terminated correctly end to end?

• a.Thermal camera
• b.Antistatic strap
• c.Multimeter
• d.Cable tester✓

A cable tester checks pin-by-pin continuity and correct termination of a network cable. A multimeter measures electrical values but not Ethernet pinout mapping directly, and the others are unrelated.

A user reports the mouse and keyboard are unresponsive but the display works. What is a quick first step?

• a.Reinstall the OS
• b.Check USB connections and try different ports✓
• c.Replace the motherboard
• d.Update the BIOS

Unresponsive input devices are often loose or on a bad port, so reconnecting or trying different USB ports is the fastest first step. Major actions like OS reinstall or board replacement are premature.

After a Windows update, a specific device stops working. What is the most targeted fix to try first?

• a.Reset the router
• b.Roll back or update that device's driver✓
• c.Replace the power supply
• d.Reinstall Windows from scratch

A single device failing after an update is usually a driver issue, so rolling back or updating that driver is the targeted fix. A full reinstall or unrelated hardware swaps are disproportionate.

A user says 'the internet is slow.' Which step best narrows the cause?

• a.Test speed on multiple devices and run ping/traceroute✓
• b.Immediately replace the router
• c.Buy a new PC
• d.Reinstall the OS

Testing several devices and running ping/traceroute distinguishes a single-device issue from a network-wide or ISP problem. Replacing hardware or reinstalling before isolating wastes effort.

A laptop screen is very dim but an external monitor works fine. What is the likely faulty component?

• a.The CPU
• b.The backlight or its power/inverter circuit✓
• c.The RAM
• d.The hard drive

If an external display works but the built-in panel is dim, the backlight or its power circuit is the likely fault. The CPU, RAM, and drive would not selectively dim the internal screen.

During troubleshooting, why is it important to question the user and identify recent changes?

• a.To delay the repair
• b.Recent changes often reveal the cause and speed diagnosis✓
• c.To assign blame
• d.To fill out paperwork only

Asking about recent changes (new hardware, updates, spills) frequently uncovers the root cause quickly. It is part of properly identifying the problem, not about blame or delay.

A computer reports a S.M.A.R.T. error at boot. What does this indicate?

• a.The hard drive/SSD is reporting predicted failure✓
• b.The GPU is overclocked
• c.The network is down
• d.The RAM is dual-channel

A S.M.A.R.T. error means the drive's self-monitoring has detected conditions predicting failure, so back up data promptly and plan replacement. It is a storage warning, not a GPU, RAM, or network message.

A PC frequently shows blue-screen (BSOD) crashes citing memory errors. What is a sound diagnostic step?

• a.Replace the monitor
• b.Reset the BIOS clock
• c.Run a RAM diagnostic and reseat/test modules✓
• d.Change the wallpaper

Memory-related BSOD codes justify running a memory diagnostic and reseating or testing modules to find faulty RAM. Display and cosmetic changes are irrelevant to memory faults.

When a proposed theory is not confirmed by testing, what should the technician do?

• a.Establish a new theory or escalate✓
• b.Close the ticket
• c.Ignore the problem
• d.Delete system files

If testing disproves the theory, the methodology says to establish a new theory of probable cause or escalate if needed. Closing or ignoring the ticket leaves the issue unresolved.

A wired PC shows 'network cable unplugged' but the cable is seated. What should be tried next?

• a.Reinstall the OS
• b.Replace the CPU
• c.Test with a known-good cable and different switch port✓
• d.Change the monitor

The message points to a physical link problem, so swapping in a known-good cable and trying another switch port isolates a bad cable or port. OS and unrelated hardware changes do not address a link-layer fault.