CompTIA A+ • Mission 03 • Core 1 Hardware

Motherboards & Connectors: Build Readiness

You already explored how power and data move through a computer. Now prepare for the hands-on PC build by learning the motherboard as a connection system, verifying component compatibility, explaining each part's job, and thinking about how A+ could turn the same concept into a scenario or performance-based task. The physical build happens in Mission 04.

Begin Mission 03 Open notebook builder Practice questions Mission 04: Build the PC

A+ quick navigation

Mission briefing

A technician does not build by shape alone.

A working PC depends on compatibility. The CPU must match the motherboard socket/platform. The motherboard must support the RAM generation and form factor. Storage needs the correct interface and slot/connector. The PSU needs appropriate capacity and connectors. Cooling must make proper contact and move heat away from the CPU.

Your job: install carefully, explain why each part belongs, and record evidence in the A+ notebook rather than copying every specification.

Meet the build

Know the job of each component before installation.

BOARD

Motherboard

The main circuit board provides physical and electrical connections for CPU, RAM, storage, expansion, firmware, power, and I/O.

PBQ: Could you identify the CPU socket, DIMM slots, M.2 slot, PCIe slot, SATA ports, and main power connector on a board image?

CPU

Executes instructions. Compatibility depends on platform/socket and motherboard support. A+ also expects awareness of x86/x64, ARM, core configurations, and cooling considerations.

Scenario clue: Fits physically does not automatically mean supported. Verify motherboard and CPU compatibility.

RAM

Fast volatile working memory. A+ compares DIMM vs. SODIMM, DDR iterations, ECC vs. non-ECC, and channel configurations.

Memory: DIMM = desktop-size module; SODIMM = smaller module commonly used in laptops and compact systems.

SSD

Storage

A+ compares HDDs and SSDs, including SATA and NVMe/PCIe interfaces, M.2 form factor, removable storage, optical drives, and RAID concepts.

PBQ: Could you select the correct storage device for a given slot and requirement?

PSU

Power Supply

Converts incoming AC to regulated DC outputs used by the computer. A+ expects input/output voltage awareness, 20+4-pin motherboard power, wattage, modular/redundant concepts, and efficiency.

Safety: Do not open a PSU enclosure. Hazardous energy can remain inside.

COOL

Cooling

Fans, heat sinks, thermal paste/pads, and liquid cooling move heat away from components. Poor contact or airflow can cause overheating, throttling, or shutdown symptoms.

Scenario: What evidence would make you investigate cooling before replacing the CPU?

Build-readiness sequence

Know the reason for every step before you install.

Important: Mission 03 prepares you to recognize the parts, connections, compatibility rules, and installation logic. The actual hands-on PC assembly happens in Mission 04.

Prepare & protect

Before the Mission 04 build, know the safety setup: power disconnected as appropriate, ESD controls in place, screws/stand-offs/tools organized, and sensitive parts handled correctly.

Exam thinking: identify the safest NEXT action before touching an internal component.

Verify compatibility

Check case/motherboard form factor, CPU socket/platform, RAM support, storage interfaces, PSU wattage/connectors, and cooler compatibility.

Notebook: make a must-match compatibility chain instead of copying full spec sheets.

CPU + thermal solution

Preview the correct logic: align the CPU correctly, secure it according to the socket mechanism, use the approved thermal interface material, and mount the cooler evenly. Never force the CPU. You will perform this in Mission 04.

RAM

Preview the correct logic: match the DDR generation and notch, use the recommended slots/channel configuration, open latches as designed, and press evenly until seated. You will perform this in Mission 04.

Storage

Identify whether the drive uses an M.2 slot, SATA data/power, or another supported interface. Know what will need to be secured and connected before Mission 04.

Mount board + PSU + cooling

Use the correct case stand-offs, install the PSU in the supported orientation, consider airflow, and keep cables clear of fans.

Stop point: the next mission can finish power/data connections, front-panel headers, expansion, firmware, POST, and boot configuration.

Compare devices you actually use

Same computing jobs, different packaging.

Function	Desktop gaming PC	Laptop	Raspberry Pi / SBC
Processor	Socketed desktop CPU in many systems	Often integrated or soldered in modern systems	SoC integrates major functions
Working memory	DIMMs	Often SODIMMs or soldered memory	Board-mounted RAM
Storage	M.2 NVMe, SATA SSD/HDD, and other supported drives	M.2/SATA or soldered storage depending on model	Commonly microSD; accessories/models may support other storage
Power	Internal PSU with multiple DC outputs/connectors	External adapter/USB-C plus battery	External low-voltage supply
A+ use	Direct Core 1 hardware installation practice	Direct Mobile Devices/hardware comparison	Architecture/Linux learning comparison; do not memorize Pi trivia for A+

A+ scenario practice

Make the build exam-ready.

1. A desktop motherboard supports a specific DDR generation. Which memory choice is BEST?

Best answer: B. Compatibility matters: form factor, DDR generation, platform support, and channel/configuration requirements.

2. Which choice describes an SSD using NVMe over PCIe in a common compact motherboard form factor?

Best answer: C. Keep form factor and interface/protocol separate: M.2 describes the physical form factor/slot, while NVMe commonly communicates over PCIe.

3. CPU temperature rises rapidly after a new cooler installation. What should the technician investigate FIRST?

Best answer: D. The evidence points to the thermal solution. Investigate the most relevant cause before replacing unrelated parts.

Notebook evidence

Build a quick-reference spread, not a copied spec sheet.

Recommended notebook spread: one large labeled motherboard/PC-build image; six short callouts for CPU, RAM, storage, PSU, cooling, and motherboard; a compatibility chain; and one box titled How could A+ ask this?

Memory vs. application: memorize fixed associations such as DIMM/SODIMM and important connector identities. Practice compatibility, installation order, symptom clues, and BEST/NEXT questions.

Certification alignment: CompTIA A+ Core 1 Domain 3 Hardware, especially 3.3 RAM characteristics, 3.4 storage devices, 3.5 motherboard/CPU/add-on-card installation and cooling, and 3.6 power supplies. This matches the class gaming-PC build focus on CPU, thermal solution, RAM, storage, motherboard, PSU, cooling, and compatibility.

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