CompTIA A+ Core 1 | Domain 3: Hardware (25%)

CompTIA A+ Core 1 | Domain 3: Hardware (25%) | Reading (1, 2, 3 & 5)

3.1 PC Hardware Overview

A computer system is made up of internal components (inside the case) and external peripherals (outside devices). Understanding how these interact is essential for troubleshooting and upgrades.

3.2 Motherboards (System Board)

What is a Motherboard?

The main circuit board that connects all components.

Key Components on a Motherboard

CPU Socket

Holds the processor
Must match CPU type (Intel vs AMD)

Chipset

Controls communication between CPU, RAM, and devices
Determines features and compatibility

RAM Slots (DIMM Slots)

Typically 2–4 slots on desktops
Dual-channel configurations improve performance

Expansion Slots

PCIe (Peripheral Component Interconnect Express)
- x1 → small cards
- x16 → graphics cards

CMOS Battery

Maintains BIOS/UEFI settings
Failure causes time reset

Power Connectors

24-pin motherboard power
4/8-pin CPU power

Form Factors (MEMORIZE)

Type	Description
ATX	Standard desktop
Micro-ATX	Smaller
Mini-ITX	Compact systems

3.3 Central Processing Unit (CPU)

CPU Basics

“Brain” of the computer
Executes instructions

CPU Features

Feature	Description
Cores	Physical processing units
Threads	Virtual cores
Clock Speed	GHz rating
Cache	Fast memory (L1, L2, L3)

Cooling the CPU

Heat sink
Fan
Thermal paste (critical for heat transfer)

3.4 RAM (Memory)

Types of RAM

Type	Description
DDR4	Common
DDR5	Faster, newer

RAM Characteristics

Volatile (data lost when power off)
Measured in GB
Speed measured in MHz

Form Factors

Type	Use
DIMM	Desktop
SODIMM	Laptop

3.5 Storage Devices

Types of Storage

HDD (Hard Disk Drive)

Mechanical
Slower
Larger capacity

SSD (Solid State Drive)

No moving parts
Faster boot times

NVMe SSD

Uses PCIe
Fastest storage type

Interfaces

Interface	Use
SATA	HDD/SSD
PCIe	NVMe

3.6 Power Supply Unit (PSU)

Function:

Converts AC power → DC power for components

Connectors:

24-pin motherboard
4/8-pin CPU
SATA power
PCIe (GPU)

Wattage:

Must support all components
High-end GPUs require more power

3.7 Expansion Cards

Common Types

Card	Purpose
GPU	Graphics processing
NIC	Network connection
Sound Card	Audio processing
RAID Card	Storage control

3.8 Input Devices

Examples:

Keyboard
Mouse
Touchscreen
Scanner

Types:

Wired (USB)
Wireless (Bluetooth)

3.9 Output Devices

Monitors

Types:

LCD
LED
OLED

Display Specs:

Spec	Meaning
Resolution	Clarity (1080p, 4K)
Refresh Rate	Smoothness (Hz)
Response Time	Speed

Printers

Types:

Type	Description
Inkjet	Home use
Laser	Office, fast
Thermal	Receipts

3.10 Connectors & Cables

Video Connectors

Type	Use
HDMI	Audio + video
DisplayPort	High resolution
VGA	Analog (legacy)

USB Standards

Type	Description
USB 2.0	Slower
USB 3.x	Faster
USB-C	Reversible, modern

3.11 BIOS / UEFI

BIOS vs UEFI

Feature	BIOS	UEFI
Speed	Slower	Faster
Interface	Text	GUI
Security	Basic	Secure Boot

Functions:

Boot order
Hardware configuration
System diagnostics

3.12 Hardware Installation

General Steps:

Power off system
Unplug power
Use ESD protection
Install component
Reconnect and test

Safety:

Avoid static electricity
Handle components by edges

3.13 Hardware Troubleshooting

Common Issues

No Power

Causes:

PSU failure
Loose cables

No Display

Causes:

GPU issue
Monitor cable

Beep Codes

Indicate hardware errors
Vary by manufacturer

Overheating

Causes:

Dust buildup
Fan failure

Slow Performance

Causes:

Low RAM
HDD bottleneck

3.14 Preventive Maintenance

Cleaning:

Remove dust regularly
Clean fans and vents

Updates:

BIOS updates
Driver updates

Safety:

Surge protectors
Proper shutdowns

Videos Hardware

3.1 – Displays

Display Types (9:13)

Our displays provide an important output technology, and there are many options for display types, configurations, and specifications. In this video, you’ll learn about LCD technologies, OLED, Mini LED, touchscreens, digitizers, and inverters.

Display Attributes (12:01)

Display technologies can vary, and it’s important to purchase the best monitor for the task at hand. In this video, you’ll learn about pixel density, refresh rates, screen resolution, and color gamut.

3.2 – Cables and Connectors

Network Cables (12:14)

We rely on our network cables to provide high-speed connectivity. In this video, you’ll learn about twisted pair cables, unshielded vs. shielded, direct burial STP cable, and plenum-rated cable.

568A and 568B Colors (5:41)

Network cables use a standard color scheme to maintain consistency around the world. In this video, you’ll learn about T568A and T568B color schemes for eight-conductor twisted pair cabling.

Optical Fiber (4:14)

Many organizations use optical fiber to connect locations over high-speed network topologies. In this video, you’ll learn the fundamentals of optical fiber and the differences between multimode fiber and single-mode fiber.

Peripheral Cables (8:59)

There are standard methods for connecting peripheral devices to our computers. In this video, you’ll learn about USB, USB-C, serial cables, and Thunderbolt technologies.

Video Cables (7:03)

Our monitors and displays connect to our computers using a number of different methods. In this video, you’ll learn about HDMI, DisplayPort, DVI, VGA, and video over USB-C.

Storage Cables (4:10)

Many of the storage devices in our modern computers rely on a cable for connectivity. In this video, you’ll learn about connecting drives with SATA and eSATA interfaces.

Adapters and Converters (4:05)

We don’t always have exactly the right cable or connector, but we might have a handy adapter or converter. In this video, you’ll learn about converting or adapting DVI to HDMI, DVI, to VGA, USB to Ethernet, USB-C to USB-A, or using one of the many interfaces on a USB hub.

Copper Connectors (8:33)

Do you have the right cable for the job? In this video, you’ll learn about RJ11, RJ45, F-connectors, punchdown blocks, USB, USB-C, Molex, Lightning, and DB-9 connectors.

Fiber Connectors (2:49)

Optical fiber allows for high-speed communication over long distances. In this video, you’ll learn about fiber optic SC, ST, and LC connectors.

3.3 – Memory

An Overview of Memory (8:38)

Memory is one of the most important components of any computer. In this video, you’ll learn about RAM, DIMMs, SO-DIMMs, SDRAM, and DDR3, DDR4, and DDR5 memory.

Memory Technologies (8:44)

Memory technologies include features to identify errors, correct issues, and improve performance. In this video, you’ll learn about parity memory, ECC memory, and multi-channel RAM.

3.4 – Storage Devices

Storage Devices (14:54)

There are many different options available for long-term data storage. In this video, you’ll learn about hard drives, solid state drives, PCIe storage, NVME, serial attached SCSI, mSATA, M.2, flash memory, and optical drives.

RAID (8:08)

We can combine multiple drives together to optimize data throughput and provide redundancy. In this video, you’ll learn about the redundant array of independent disks (RAID), and an overview of RAID 0, RAID 1, RAID 5, RAID 6, and RAID 1+0.

3.5 – Motherboards

Motherboard Form Factors (6:18)

When purchasing or building a computer, you have a many options for motherboard type and form factor. In this video, you’ll learn about the ATX motherboard standard, the micro-ATX standard, and the ITX motherboard form factors.

Motherboard Expansion Slots (7:14)

If you’re adding on features to an existing motherboard, then you may be connecting to one of the available expansion slots. In this video, you’ll learn about PCI (Peripheral Component Interconnect) and PCIe (PCI Express) expansion slot technologies.

Motherboard Connections (5:45)

There are many connectors on a typical motherboard. In this video, you’ll learn about power connections, storage drive interfaces, and working with motherboard header pins.

Motherboard Compatibility (3:29)

There are many options available for motherboard features and capabilities. In this video, you’ll learn about the differences between Intel-based and AMD-based motherboards and the specifications commonly found on server motherboards.

The BIOS (4:42)

The BIOS is responsible for getting our systems running each time we hit the start button. In this video, you’ll learn about the Basic Input/Output System and how the UEFI BIOS is used to manage and protect our modern computer systems.

BIOS Settings (19:29)

The BIOS configuration options provide extensive customization. In this video, you’ll learn about boot options, USB permissions,

HSM and TPM (7:47)

The trusted platform module (TPM) is an important security feature on today’s motherboards. In this video, you’ll learn about the technologies and use cases of TPMs and hardware security modules (HSMs).

CPU Features (5:13)

Our modern CPUs include a number of valuable features. In this video, you’ll learn about the differences between 32-bit and 64-bit processors, the advantages associated with ARM processors, and how CPU cores can be a useful measurement of processing power.

Expansion Cards (6:17)

Our computers are designed for expandability through the use of expansion cards. In this video, you’ll learn about sound cards, video adapters, capture cards, network interface cards, and best practices for installing new drivers.

Cooling (6:37)

One of the by-products of computing is the generation of heat. In this video, you’ll learn how we cool our computing systems using fans, passive cooling, heat sinks, thermal paste, thermal pads, and liquid cooling.

3.6 – Power

Computer Power (15:31)

Without power, our computers aren’t very useful. In this video, you’ll learn about computer power supplies, power specifications, redundant power supplies, and power supply efficiency ratings.

3.7 – Multifunction Devices

Multifunction Devices (14:25)

Today’s all-in-one multifunction devices can act as a printer, scanner, copier, and more. In this video, you’ll learn about setting up a multifunction device, configuring a printer language, setting individual print features, configuring badging and secure printing, and working with a flatbed scanner.