CompTIA A+ Study Guide

1.1 Laptop Hardware

• • Display types: LCD, LED, OLED, TN, IPS, VA
• • WiFi antenna connector/placement
• • Webcam, microphone, speakers
• • System board, DC jack, battery
• • Keyboard, touchpad, function keys

1.2 Mobile Device Accessories

• • Connection types: USB, Lightning, USB-C, Thunderbolt
• • Accessories: headsets, speakers, game pads, docking stations

1.3 Mobile Device Connectivity

• • Wireless: Bluetooth, NFC, cellular, WiFi
• • Mobile device synchronization methods

2.1 TCP/IP and Ports

• • IPv4: Classes, private ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16)
• • IPv6: Address structure, link-local (FE80::)
• • Common ports: HTTP (80), HTTPS (443), FTP (20/21), SSH (22), Telnet (23)
• • DNS (53), DHCP (67/68), SMTP (25), POP3 (110), IMAP (143)
• • RDP (3389), SMB (445), AFP (548), NetBIOS (137-139)

2.2 Network Devices

• • Router, switch, access point, modem, firewall
• • Patch panel, PoE switch, hub
• • Cable modem, DSL modem, ONT

2.3 Wireless Standards

• • 802.11a (5 GHz, 54 Mbps), 802.11b (2.4 GHz, 11 Mbps)
• • 802.11g (2.4 GHz, 54 Mbps), 802.11n (2.4/5 GHz, 600 Mbps)
• • 802.11ac (5 GHz, 1+ Gbps), 802.11ax/WiFi 6 (2.4/5 GHz, 9.6 Gbps)

2.4 Network Types and Services

• • LAN, WAN, PAN, MAN, SAN, WLAN
• • DHCP, DNS, file sharing, print services

3.1 Cables and Connectors

• • Network: Cat 5, Cat 5e (100m), Cat 6 (55m for 10Gbps), Cat 6a (100m)
• • Fiber: Single-mode, multi-mode
• • Video: HDMI, DisplayPort, DVI, VGA, Thunderbolt
• • Peripheral: USB 2.0/3.0/3.1/3.2, USB-C, Lightning
• • Storage: SATA, eSATA, IDE/PATA

3.2 RAM Types

• • DDR3, DDR4, DDR5 (desktop: DIMM, laptop: SO-DIMM)
• • ECC vs non-ECC, registered vs unbuffered
• • Single-channel, dual-channel, triple-channel, quad-channel

3.3 Storage Devices

• • HDD: Magnetic storage, 5400/7200 RPM
• • SSD: SATA, M.2, NVMe (PCIe interface)
• • RAID: 0 (striping), 1 (mirroring), 5 (striping with parity), 10 (1+0)

3.4 Motherboards and CPUs

• • Form factors: ATX, microATX, Mini-ITX
• • Chipset, expansion slots: PCIe x1/x4/x8/x16
• • CPU sockets: Intel LGA, AMD AM4/AM5

3.5 Power Supplies

• • Input: 115V or 230V (voltage selector)
• • Connectors: 20/24-pin ATX, 4/8-pin CPU, 6/8-pin PCIe, SATA, Molex
• • Wattage ratings, efficiency (80 PLUS)

4.1 Cloud Models

• • IaaS (Infrastructure as a Service): Virtual machines, storage
• • PaaS (Platform as a Service): Development platforms
• • SaaS (Software as a Service): Web-based applications
• • Public, private, hybrid, community cloud

4.2 Virtualization

• • Hypervisor Type 1 (bare metal) vs Type 2 (hosted)
• • Virtual machine resource requirements
• • Network, storage, and security resources for VMs

5.1 Troubleshooting Methodology

1. Identify the problem
2. Establish a theory of probable cause
3. Test the theory to determine cause
4. Establish a plan of action and implement the solution
5. Verify full system functionality
6. Document findings, actions, and outcomes

5.2 Common Hardware Issues

• • POST beep codes, no power, overheating
• • Blue screen of death (BSOD), black screen
• • Distorted display, incorrect color patterns
• • Boot failures, grinding noises

5.3 Network Troubleshooting

• • No connectivity, intermittent connectivity
• • IP conflict, slow transfer speeds
• • Limited connectivity, unavailable resources