Comptia A+

Electrostatic Discharge (ESD)

Damage caused by the transfer of electrons from a statically charged body to an uncharged component

CompTIA Six-Step Troubleshooting Methodology

Identify the Problem, establish a theory of probable cause, test the theory to determine the cause, establish a plan of action, implement the solution, and document the results.

Components of a Custom PC

motherboard, central processing unit(CPU), Memory(RAM), storage devices, cooling fans, power supply unit(PSU)

USB (Universal Serial Bus)

Widely used interface standard that connects various devices, providing

both data transfer and power delivery capabilities while supporting

multiple devices via daisy-chaining

Serial Connections (Predecessor to USB)

Serial cables used DB9 and DB25 connectors with a D-shaped design and thumbscrews for secure attachment

■ These cables transmitted data at a slow speed of up to 115 Kbps by

sending one bit at a time

■ Serial connections were limited to one device per port and were primarily

used for older mice, keyboards, and external modems

■ Today, serial cables are rarely used but can still be found in legacy

applications such as connecting to routers and switches

USB 1.0 transfer speed

1.5 Mbps

USB 1.1

12 Mbps

USb 2.0

supports up to 480 Mbps

USB 3.0

Referred to as SuperSpeed USB, offers speeds of up to 5 Gbps

USB 3.1 Gen 2

superspeed+ usb reaches speeds of 10 Gbps

USb 3.2 gen 2X2

20 Gbps

USB 4.0

The latest USB standard that supports data transfer speeds of up to 40 Gbps and improves overall performance and power delivery.

USB Distance Limitations (1.0, 1.1, 2.0, 3.0)

USB 1.0 had a cable length limit of 3 meters (9 feet)

■ USB 1.1 and USB 2.0 increased the maximum cable length to 5 meters (15

feet)

■ USB 3.0 and later versions reduced the limit back to 3 meters (9 feet) to

maintain high-speed performance

USB 1.0 and 2.0 power delivery

maximum power output of 500 mA (0.5A)

USB 3.0 power delivery

900Ma

USB Type A connector types

Flat rectangular connector used in USB 1.0, 1.1, 2.0, 3.0, and above

■ Connects only in one direction due to a blocking piece inside the port

■ Commonly found on desktops and laptops

USB Type B connector types

Used for larger devices like printers

■ Includes three variations

Type B Connector

Square with rounded corners on top

●

Type B Mini Connector

Trapezoid shape; found on early tablets and smartphones

●

Type B Micro Connector

Shorter, skinnier version; used for wearables, smart

glasses, and small music players

HDMI Type A

Full size HDMI connector used in most devices

HDMI type c

mini hdmi for compact devices like camera

HDMI type D

micro hdmi for portable devices such as smart phones

Cable Categories

Standard (Category 1)

supports up to 1080p

cable categories high-speed(category 2)

supports 4k and 8k with speeds up to 48Gbps

Display port (DP)

Open-standard video interface developed by VESA to compete

with HDMI, offering high-speed video and audio transmission used for PC monitors, professional graphics applications, and high-end gaming

DP connector types

full size which includes a locking mechanism and mini DP used in compact devices like laptops

DVI( Digital Visual Interface)

Older standard version supports both analog and digital video signals used in older monitor systems limited to 1080p resolution and no native support for audio

VGA(video graphics array)

analog video connection standard used in older computers, projectors its a 15-pin d sub connector carriers red, green and blue colors separately with a maximum resolution of 640×480 pixels

thunderbolt

a high speed interface developed by apple that supports video, data and power with a single connection used in high performance laptops, workstations and data storage devices

thunderbolt 1 and 2 connector types

uses mini DP connectors

thunderbolt 3 and 4

uses Type-C connectors with speeds uo to 40 Gbps

storage cables

Cables used to connect storage devices such as hard drives, solid-state

drives (SSDs), and optical drives to computers, enabling data transfer

between the device and system

SATA( serial advanced technology attachment)

Standard internal storage connection used in desktops and

laptops

SATA connector types

data cable 7 pin L shape

power cable 15 pin connector

SATA 1 power speeds

1.5 Gbps

SATA II power speed

3 Gbps

SATA III power speeds

6 Gbps

eSATA

External version of SATA for connecting external drives

SCSI(small computer system interface)

Legacy storage interface for connecting multiple devices

narrow SCSI

supports up to 7 devices

Wide SCSI

supports up to 15 devices

SAS( Serial Attached SCSI)

Modern enterprise grade storage connection used in high performance environments

SAS speed supportage

up to 24 Gbps

Common uses of SAS

used in enterprise data centers, servers and mission critical applications

what storage cable power needs separate power connection

SATA

what is form factors for motherboards

Describes the shape, layout, and type of case and power supply compatible with a motherboard It determines the number and type of components that can be installed and is the foundation for building a custom PC

what is ATX(Advanced technology eXtended) size

12 × 9.6 inches

Mini-ATX size

11.2 × 8.2 inches

microATX size

9.6 × 9.6

why was ITX(Information technology eXtended) created

to replace ATX but the full size ITX was never commercially produced

Nano-ITX, Pico.ITX, Mobile-ITX uses

was built for embedded systems and portable devices

All ATX boards( Full, Mini, Micro) fit in

Full size ATX cases

what does the CPU do

executes program code in software or firmware also performs basic operations for instructions

how does the CPU operate

Fetches the next instruction from system memory or processor cache

■ Decodes the instruction through the control unit

■ Executes the instruction or passes it to a secondary unit for completion

■ Sends the result to the register, cache, or memory for storage or further

use

what is cache

high speed memory inside the processor

what are the three main types of architectures

x86, x64 and ARM

what are CPU Sockets

A connector on a motherboard that houses the central processing unit

(CPU) and facilitates communication between the CPU and other

components

what are the two primary manufactures of desktop computing CPU

Intel and AMD

what is socket mechanism ZIF(Zero Insertion Force)

A mechanism ensuring CPU can be installed without force

what are the socket types

LGA(land grid array) and PGA(Pinn Grid Array)

LGA specs

manufactured by intel pins are on the motherboard and commonly used in desktops, workstations and servers using intel processors

PGA specs

manufactured by AMD pins are on the cpu and motherboard has corresponding holes

soldered processors common uses

commonly used in mobile devices

single socket system used most commonly in

desktops and laptops and have a single physical cpu socket

multi socket system most commonly used in

workstations and servers needing high processing power and supports two or more CPU’s

what is advanced multi core processing

Combines multi-core and multithreading for enhanced performance

what is virtualization support

enables hardware to emulate multiple virtual computers

what are the types of cooling

passive cooling, active cooling, liquid cooling

explain closed loop liquid cooling system

Self-contained systems cooling a single component

explain open loop liquid cooling system

Customizable systems capable of cooling multiple components

How Open Loop Systems Work

Coolant absorbs heat from components via the water block/bracket

■ Heated coolant flows through tubing to the radiator

■ Radiator cools the liquid using airflow over its fins

■ Cooled liquid returns to components, repeating the process in a loop

what’s a PSU( power supply unit)

PSUs provide direct current (DC) power to computer components

■ Converts alternating current (AC) from wall outlets into low-voltage DC

key components of a PSU

transformer, regulators and filters and fans

types of PSU

traditional and modular

what’s voltage transformation

Input AC voltage is reduced and converted to DC using

transformers, filters, and rectifiers

what are rails

A rail refers to a wire or circuit providing a specific voltage level

Common rails are

+12 volts, +5 volts, +3.3 volts

what are power supply connectors

DC voltages are distributed to components via various connectors

what is RAM(random access memory)

Temporary storage for data and instructions before processing by the CPU

what is cache

high-speed memory in the cpu nut its a small capacity

what is memory addressing

processor accesses data in RAM using unique addresses

what is data bus

determines the amount of data transferred per clock cycle

what is address bus

determines how much memory the copy can address

how much memory can 32-bit address

up to 4 gb

how much memory can 32-bit address

16 exabytes

what’s the limitations of a 32-bit system with 4Gb of ram

it cannot efficiently run modern operating systems

what’s the advantages of a 64 bit system with 16gb of ram

well it allows for better performance and multitasking

what are the types of memory modules

DIMM(Dual in-line memory modules) and SODIMM(small outline DIMM)

what is DRAM(dynamic RAM)

requires constant refreshing

what is SRAM(static RAM)

Faster, used in CPU caches (L1,L2,L3), expensive