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Question bank
CompTIA A+ (Core 1)
43 CompTIA A+ (Core 1) questions with the correct answer and a written explanation, organised across 5 exam domains.
- 43 questions
- 5 domains
- Foundation level
certilumQuestion index
Jump straight to any question. Answers and explanations are inline.
Hardware
10 questions in this domain
- Question 1Single Choice
In laptop service, what does the term 'field replaceable unit' (FRU) mean?
- AA component that a technician can replace in the fieldCorrect answer
- BA component that is always user upgradeable
- CA component permanently soldered to the motherboard
- DA component that never requires service
Why this is the answer
A field replaceable unit is designed to be replaced on-site by a technician, but it may not be user upgradeable.
- Question 2Multiple Select
Which statements about M.2 keys are true? Select two.
- AM-key slots commonly support PCIe/NVMe devices.Correct answer
- BAn M-key slot always requires an NVMe drive.
- CB-key slots commonly support SATA devices.Correct answer
- DA B-key slot only works with NVMe drives.
Why this is the answer
M.2 keying indicates physical compatibility, not protocol. M-key commonly supports PCIe/NVMe, while B-key commonly supports SATA.
- Question 3Interactive
According to the service note shown above, what must be checked before installing a wireless card?
- ABIOS/UEFI whitelistCorrect answer
- BBattery health
- CScreen size
- DDigitizer cable
Why this is the answer
The note states that only certified wireless cards are allowed to boot, so the technician should check the BIOS/UEFI whitelist.
- Question 4Single Choice
A laptop has no display, but an external monitor works. Which failure is most likely?
- ADamaged eDP cable or backlightCorrect answer
- BThe LCD panel itself
- CThe keyboard
- DThe Wi-Fi card
Why this is the answer
When external display works, the GPU is functional; internal display loss usually points to the eDP cable, backlight, or panel.
- Question 5Multiple Select
Which components are commonly soldered in ultraportable laptops? Select two.
- ARAMCorrect answer
- BKeyboard
- CStorageCorrect answer
- DDisplay bezel
Why this is the answer
Ultraportables often solder RAM and storage to save space, making upgrades difficult or impossible.
- Question 6Interactive
What does a faint image in the flashlight test indicate?
- AFailed backlightCorrect answer
- BFailed LCD
- CFailed GPU
- DFailed eDP cable
Why this is the answer
A faint image shows the LCD is producing an image, so the failure is in the backlight, not the panel.
- Question 7Single Choice
What is the primary difference between eDP and LVDS display connectors?
- AThey use different pinouts and voltagesCorrect answer
- BThey are identical and interchangeable
- CeDP is used only for power
- DLVDS carries only audio
Why this is the answer
eDP and LVDS cables may look similar, but their pinouts and voltage requirements differ, so they cannot be interchanged.
- Question 8Multiple Select
Why should the battery be disconnected before replacing a display cable? Select two.
- ATo avoid exposed power during serviceCorrect answer
- BTo make the screen brighter
- CTo prevent electrical shortsCorrect answer
- DTo improve wireless signal
Why this is the answer
Disconnecting the battery protects against shorts and prevents power from reaching exposed components during repairs.
- Question 9Interactive
Based on the note, what should be checked when touch stops working after a screen replacement?
- ADigitizer cableCorrect answer
- BHinge screws
- CBacklight
- DWireless antenna
Why this is the answer
The digitizer cable carries touch signals from the screen; if it is disconnected, touch will not function.
- Question 10Single Choice
What can happen if hinge screws are overtightened?
- AThreads can strip in soft metal or plasticCorrect answer
- BThe screen becomes brighter
- CThe laptop runs faster
- DNo effect
Why this is the answer
Hinge holes are often threaded into soft material, so overtightening can strip the threads and damage the chassis.
Hardware and Network Troubleshooting
12 questions in this domain
- Question 11Single Choice
Which statement best describes a field replaceable unit (FRU) in a laptop?
- AA technician-replaceable componentCorrect answer
- BA user-only upgrade part
- CA motherboard-soldered part
- DA part that never fails
Why this is the answer
A field replaceable unit can be swapped at the customer site by a trained technician, but it is not necessarily user-upgradeable.
- Question 12Multiple Select
Which precautions should be taken when replacing a laptop display panel? (Select two.)
- ADisconnect the battery firstCorrect answer
- BCheck the eDP cable or backlightCorrect answer
- CAssume the LCD is defective
- DTighten hinge screws firmly
Why this is the answer
Display symptoms can be caused by the eDP cable or backlight, and battery power must be disconnected before servicing. Hinge screws must not be overtightened.
- Question 13Interactive
According to the hardware inventory in the diagnostic output, which component is soldered and cannot be upgraded?
- ARAMCorrect answer
- BSSD
- CWireless card
- DBattery
Why this is the answer
The output marks RAM as 'onboard,' meaning it is soldered to the motherboard and not user-replaceable in this ultraportable.
- Question 14Single Choice
Which M.2 key is most commonly associated with PCIe/NVMe solid-state drives?
- AM-keyCorrect answer
- BB-key
- CA-key
- DE-key
Why this is the answer
M-key slots commonly support PCIe/NVMe SSDs, while B-key slots are often used for SATA or less common PCIe designs.
- Question 15Multiple Select
A business laptop stops at POST with an 'unsupported wireless card' message. Which two steps should the technician take?
- ACheck the approved wireless card listCorrect answer
- BInstall an approved wireless cardCorrect answer
- CDisable the whitelist in the standard BIOS menu
- DUse any M.2 wireless card
Why this is the answer
Many business laptops use a BIOS/UEFI whitelist. Technicians must consult approved hardware lists and install a compatible card.
- Question 16Interactive
According to the diagnostic log, which component is the most likely failure?
- ALCD panel
- BBacklightCorrect answer
- CeDP cable
- DDigitizer
Why this is the answer
A faint image under the flashlight means the LCD panel is receiving image data, while the backlight is not glowing.
- Question 17Single Choice
Why can an eDP cable not be used in place of an LVDS cable?
- ADifferent connectors and signalingCorrect answer
- BElectrically identical parts
- COnly the cable length differs
- DSame connector but different color
Why this is the answer
eDP and LVDS are different display interfaces with different connector layouts and signals; mixing them can damage components.
- Question 18Multiple Select
Which two actions should be performed before servicing a laptop display assembly?
- ARemove AC adapter and disconnect batteryCorrect answer
- BUse an ESD wrist strapCorrect answer
- CKeep the battery connected to test voltage
- DRoute cables under hinge screws
Why this is the answer
Disconnecting power and using ESD protection are essential. Cables should not be routed under hinge screws, and the battery should be disconnected.
- Question 19Interactive
Based on the service note, why is touch not functional after the screen replacement?
- ADigitizer cable is disconnectedCorrect answer
- BLCD panel is defective
- CBacklight inverter has failed
- DWireless card is not approved
Why this is the answer
The digitizer cable must be reconnected when replacing a touchscreen display; ignoring it causes loss of touch input.
- Question 20Single Choice
What problem can result from overtightening laptop hinge screws?
- AThreads strip in soft materialCorrect answer
- BHinge moves faster
- CWireless range improves
- DLCD becomes brighter
Why this is the answer
Hinge holes are often threaded into soft material, so overtightening can strip threads and crack the surrounding casing.
- Question 21Multiple Select
Which two components are commonly soldered in ultraportable laptops?
- ALPDDR4x RAMCorrect answer
- BeMMC storageCorrect answer
- CM.2 NVMe SSD
- DSocketed CPU
Why this is the answer
Ultraportables often use soldered RAM and storage, such as LPDDR4x and eMMC, making upgrades difficult or impossible.
- Question 22Interactive
The user's laptop screen is very dark. Based on the backlight output, what should be checked first?
- ABrightness settingCorrect answer
- BLCD panel
- CeDP cable
- DDigitizer
Why this is the answer
The backlight log shows a brightness value of zero, indicating the display is dark because the system brightness is set to minimum.
Mobile Devices
6 questions in this domain
- Question 23Single Choice
A laptop internal part is labeled as a field replaceable unit (FRU). What does this label typically indicate?
- AIt is designed to be replaced by a qualified technician.Correct answer
- BIt is an easy user-upgradeable component.
- CIt is a software setting that must be changed.
- DIt is permanently fixed and cannot be replaced.
Why this is the answer
FRUs are parts that a technician is authorized to replace on a laptop, unlike user-upgradeable components. The term does not mean the user can hot-swap it without disassembly.
- Question 24Multiple Select
Which two statements about M.2 M-key and B-key slots on laptop motherboards are correct? Select two.
- AM-key slots are commonly used for PCIe/NVMe SSDs.Correct answer
- BB-key slots are commonly used for SATA SSDs and some wireless cards.Correct answer
- CAn M-key SSD can be installed in a B-key slot without an adapter.
- DB-key slots always support NVMe, and M-key slots always support SATA.
Why this is the answer
M-key slots usually support PCIe/NVMe, while B-key slots typically support SATA and other interfaces. Keying prevents cross-insertion, so the two designs are not interchangeable.
- Question 25Interactive
A technician replaced a laptop's wireless card with an aftermarket card. When the system boots, it shows the message in the code block. What should the technician do first?
- AInstall an approved wireless card listed in the BIOS/UEFI whitelist.Correct answer
- BDisable the BIOS whitelist using a motherboard jumper.
- CReflash the BIOS with unofficial firmware to bypass the check.
- DReplace the system board immediately.
Why this is the answer
Many business laptops enforce a BIOS/UEFI whitelist for wireless cards. Using an unsupported card triggers a boot-blocking error; the correct fix is to install an approved FRU.
- Question 26Single Choice
A laptop has a blank built-in display, but the backlight is on and an external monitor displays correctly. Which is the most likely failure?
- ADamaged eDP cable connecting the motherboard to the display.Correct answer
- BFailed backlight inverter.
- CDefective GPU.
- DIncorrect screen resolution setting.
Why this is the answer
Backlight on plus no image points to a video-signal problem, often a damaged eDP cable. Since the external monitor works, the GPU is functioning.
- Question 27Multiple Select
Which two components are frequently soldered to the motherboard in ultraportable laptops, preventing easy upgrades? Select two.
- ASystem memory (RAM)Correct answer
- BInternal storage (SSD)Correct answer
- CAC power jack
- DKeyboard
Why this is the answer
Many ultraportables use soldered LPDDR RAM and embedded storage to save space. Users should verify the configuration before purchase because these parts cannot be upgraded easily.
- Question 28Interactive
A technician uses a flashlight test on a laptop with a blank screen. The result matches the code block. Which component failed?
- ABacklight assemblyCorrect answer
- BLCD panel
- CeDP cable
- DGraphics chip
Why this is the answer
A flashlight test showing a faint image means the LCD is forming an image but the backlight has failed. Replacing the LCD would not correct the fault.
Networking
10 questions in this domain
- Question 29Single Choice
In laptop repair, what does the term 'field replaceable unit' (FRU) usually mean?
- AA part that can be replaced at a repair center without sending the whole laptop to the factoryCorrect answer
- BA part that any home user may upgrade without opening the case
- CA part that must be soldered to the motherboard and cannot be removed
- DA part that can only be replaced by the laptop manufacturer
Why this is the answer
An FRU is designed for field-level service. It may require a technician and is not necessarily user-upgradeable.
- Question 30Multiple Select
Which statements about M.2 slots are correct based on the playbook?
- AM-key slots usually support PCIe/NVMeCorrect answer
- BB-key slots are always SATA
- CB-key slots may support SATA or PCIe depending on the modelCorrect answer
- DAll M-key slots support only SATA
Why this is the answer
M-key usually pairs with PCIe/NVMe, while B-key is not always SATA; some B-key slots also support PCIe.
- Question 31Interactive
A business laptop displays the message shown after a new wireless card is installed. What is the most likely cause?
- AThe wireless card is not on the BIOS/UEFI whitelistCorrect answer
- BThe M.2 slot is physically damaged
- CThe display cable is not connected
- DThe digitizer cable is unavailable
Why this is the answer
Many business laptops have a BIOS/UEFI whitelist that blocks wireless cards not approved for that model.
- Question 32Single Choice
What is a common misconception about M.2 storage slots highlighted in the playbook?
- AM-key slots are always NVMe and B-key slots are always SATACorrect answer
- BM-key slots are always SATA and B-key slots are always NVMe
- CBoth M-key and B-key slots always support SATA only
- DM.2 slots are only used for wireless cards
Why this is the answer
Technicians often assume M-key always means NVMe and B-key always SATA, but B-key can also support PCIe.
- Question 33Multiple Select
Which components are commonly soldered in ultraportables, according to the playbook?
- ARAMCorrect answer
- BStorageCorrect answer
- CWireless card
- DDisplay panel
Why this is the answer
Ultraportables often solder RAM and storage to the motherboard, making replacement impossible without specialized equipment.
- Question 34Interactive
A dark laptop screen shows a faint image when a flashlight is held to it. What does this test reveal?
- AThe backlight has failedCorrect answer
- BThe LCD panel has failed
- CThe digitizer cable is disconnected
- DThe battery needs to be replaced
Why this is the answer
A faint image means the LCD is producing an image, but the backlight is not illuminating it.
- Question 35Single Choice
What is a key difference between eDP and LVDS connectors?
- AThey look similar but have different pinouts and are not interchangeableCorrect answer
- BThey are electrically identical
- CLVDS is the newer standard
- DeDP cables are always longer than LVDS cables
Why this is the answer
eDP and LVDS can look alike but have different pinouts; swapping them can cause display failures.
- Question 36Multiple Select
Which precautions should be taken before display cable replacement or panel swap?
- ADisconnect the batteryCorrect answer
- BKeep the battery connected to maintain BIOS settings
- CAssume the display area has no power hazards
- DHandle exposed power connections carefullyCorrect answer
Why this is the answer
Display repairs involve exposed power, so disconnect the battery and treat power connections as hazards.
- Question 37Interactive
A user says the new screen works, but touch is unresponsive. Which cable might have been overlooked?
- ADigitizer cableCorrect answer
- BeDP cable
- CWireless antenna cable
- DSpeaker cable
Why this is the answer
The digitizer carries touch signals. If it is not reconnected, the screen will work but touch will not.
- Question 38Single Choice
What does the playbook warn about overtightening hinge screws?
- AThe screw threads strip because hinge holes are often threaded into soft materialCorrect answer
- BThe backlight becomes brighter
- CThe touchscreen becomes unresponsive
- DThe wireless card is rejected
Why this is the answer
Hinge holes often have soft threads that strip easily when overtightened.
Virtualization and Cloud Computing
5 questions in this domain
- Question 39Single Choice
What is the key difference between a field replaceable unit (FRU) and a user-upgradeable component in a laptop?
- AAn FRU can only be replaced by the original manufacturer.
- BAn FRU is designed for replacement by technicians and might still require partial disassembly.Correct answer
- CA user-upgradeable part is always soldered to the motherboard.
- DFRU and user-upgradeable are interchangeable terms.
Why this is the answer
A field replaceable unit is a component technicians are expected to replace in the field, although it may require disassembly. User-upgradeable components are designed to be replaced by the end user with minimal effort.
- Question 40Multiple Select
Which statements about M.2 keys are correct based on common laptop misunderstandings?
- AAn M-key slot always provides SATA connectivity.
- BAn M-key slot usually supports PCIe/NVMe SSDs.Correct answer
- CA B-key slot can support SATA interfaces.Correct answer
- DA B-key slot always runs at SATA speeds only.
Why this is the answer
M.2 M-key slots commonly support PCIe/NVMe, while B-key slots are not restricted to SATA in all cases. Assuming B-key always means SATA is a common trap.
- Question 41Interactive
Based on the service note, why would a newly installed wireless card not be recognized?
- AThe BIOS/UEFI whitelist is blocking the unauthorized card.Correct answer
- BThe M.2 key is physically incompatible.
- CThe eDP cable is damaged.
- DThe battery was not disconnected.
Why this is the answer
Many business laptops include a BIOS/UEFI wireless whitelist that allows only specific approved part numbers to initialize and operate.
- Question 42Single Choice
A technician holds a flashlight to a laptop screen and sees a very faint image. Which component is most likely failing?
- ABacklightCorrect answer
- BLCD panel
- CeDP cable
- DDigitizer
Why this is the answer
A faint visible image when a flashlight is held to the screen indicates the LCD panel is producing an image, but the backlight has failed.
- Question 43Multiple Select
Which two conditions can cause a blank laptop display and are often mistaken for a failed LCD panel?
- ADamaged eDP cableCorrect answer
- BFailed backlightCorrect answer
- CUEFI wireless whitelist
- DDigitizer cable disconnection
Why this is the answer
A blank display can be caused by a damaged eDP cable or a failed backlight. Checking these first can prevent replacing a functional LCD panel.
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