Introduction to Storage
Terms and Definitions
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Persistent data – data that does not require the presence of an electrical current to retain the data
Non-persistent data – this type of data requires the presence of an electrical current
Volatile – requires the presence of electrical current
Non-volatile – does not require the presence of an electrical current
HDD - Hard Disk Drive - a storage mechanism that stores data magnetically using multiple platters, a
read/write heads and motors.
SSD – Solid State Drive – a storage mechanism that stores data in integrated circuits called semiconductor
cells, like system memory. However, unlike system memory the data is persistent.
NVMe – Non-Volatile Memory Express – a host controller interface and storage protocol, allowing for the
connection of SSDs over Peripheral Component Interconnect Express (PCIe)
PATA – Parallel Advanced Technology Attachment - originally AT Attachment, is an interface standard for the
connection of storage devices such as hard disk drives, floppy disk drives, and optical disc drives in computers.
SATA – Serial Advanced Technology Attachment – An interface that connects drive controllers/ host bus
adapters to mass storage devices such as hard disk drives, optical drives and solid-state drives. Serial ATA
replaced the older Parallel ATA standard
SCSI – Small Computers Systems Interface – a set of standards that provide commands, protocols, electrical,
optical and logical interfaces to transfer data between computers and peripheral devices.
SAS – Serial Attached SCSI – is a point-to-point serial protocol that moves data to and from computer-storage
devices such as hard drives and tape drives. Serial attached SCSI replaced the older parallel SCSI bus
technology.
USB – Universal Serial Bus – an interface that allows a computer system to communicate with peripheral
devices such as storage drives, keyboards, mice, thumb drives, charging cables and more.
Hot Swappable – a term that defines the process of adding or removing a component without powering off the
system unit (Example: USB thumb drives can be plugged into and removed from a system while that system is
powered on.)
IOPS - Define the number of input/output instructions per second to non-contiguous storage locations
○ https://en.wikipedia.org/wiki/IOPS
transfer rate - a measurement how fast data can be transferred from contiguous storage locations
○ https://www.techopedia.com/definition/17315/transfer-rat
Magnetic Storage
Terms, Definitions, Specifications & Acronyms
➢ Magnetic storage – Magnetic storage or magnetic recording is the storage of data on a magnetized medium.
Magnetic storage uses different patterns of magnetization in a magnetizable material to store data. The
information is accessed using one or more read/write heads.
➢ HDD - Hard Disk Drive - a storage mechanism that stores data magnetically using multiple platters, a
read/write heads and motor
➢ SATA – Serial Advanced Technology Attachment – An interface that connects drive controllers/ host bus
adapters to mass storage devices such as hard disk drives, optical drives and solid-state drives. Serial ATA
replaced the older Parallel ATA standard
➢ AHCI – Advanced Host Controller Interface - is a programming standard that defines a new mode of operation
for SATA that adds two extra features; Native Command Queuing (NCQ) and hot-plugging/hot-swapping
➢ NCQ – Native Command Queuing – is a technology designed initially to increase performance of SATA hard
disks under certain conditions by allowing the individual hard disk to internally optimize the order in which
received read and write commands are executed.
➢ SCSI – Small Computers Systems Interface – a set of standards that provide commands, protocols, electrical,
optical and logical interfaces to transfer data between computers and peripheral devices.
➢ HBA – Host Bus Adapter - In computer hardware, a host controller, host adapter, or host bus adapter connects
a computer, which acts as the host system, to other network and storage devices. the terms are primarily used
to refer to devices for connecting SCSI, Fiber Channel and SATA
➢ SAS - Serial Attached SCSI – is a point-to-point serial protocol that moves data to and from computer-storage
devices such as hard drives and tape drives. Serial attached SCSI replaced the older parallel SCSI bus
technology.
➢ Hot Swappable – a term that defines the process of adding or removing a component without powering off the
system unit (Example: USB thumb drives can be plugged into and removed from a system while that system is
powered on.)
➢ Parallel Advanced Technology Attachment /Parallel ATA (PATA), originally AT Attachment, is an interface
standard for the connection of storage devices such as hard disk drives, floppy disk drives, and optical disc
drives in computers. ○ https://en.wikipedia.org/wiki/Parallel_ATA for the PATA standards
➢ Floppy drives (Obsolete/Legacy)
○ Mechanical
○ Magnetic
○ 34 pin data connector
○ 4 pin Berg power connector
○ Two form factors
■ 5.25” (oldest)
■ 3.5”
○ 3.5” single-sided disk = 720 KB
○ 3.5” double-sided disk = 1.44 MB
Magnetic Storage Performance articles
➢ https://en.wikipedia.org/wiki/Hard_disk_drive_performance_characteristics
➢ http://www.buildcomputers.net/hard-disk-speed.html
➢ SATA Express* – (SATAe) - is a computer bus interface that supports both Serial ATA (SATA) and PCI Express
(PCIe) storage devices, initially standardized in the SATA 3.2 specification
➢ SATA Specifications
SATA 1.0
SATA 2.0
SATA 3.0
SATA 3.2
1.5 Gbps
3 Gbps
6 Gbps
SATA Express
SCSI Specifications
SCSI Specification
Width(bits)
Throughput (per sec)
Cable Characteristics
SCSI-1
8
5 MBps
6m meter cable
Fast SCSI
8
10 MBps
3m cable
Fast-Wide SCSI
16
20 MBps
3m cable
Ultra SCSI
8
20 MBps
3m cable
Ultra-Wide SCSI
16
40 MBps
3m
Ultra2 SCSI
8
40 MBps
Introduced Low Voltage
Differential (LVD), 12m cable
Ultra2-Wide SCSI
16
80 MBps
LVD, 12m cable
Ultra3 SCSI
16
160 MBps
Adds cyclic redundancy check
(CRC = error detection)
Ultra-320
16
320 MBps
Most common at the end of
parallel SCSI’s implementation
Ultra-640
16
640 MBps
Not popular, replaced by Serial
Attach SCSI (SAS)
➢ Serial SCSI Standards
➢ SSA – Serial Storage Architecture – 192 hot-swappable hard disks per system, using SCSI commands at 80
MBps
➢ Fiber Channel – is a high-speed data transfer protocol providing in-order, lossless delivery of raw block data,
primarily used to connect computer data storage to servers. Fiber Channel is mainly used in storage area
networks (SAN) in commercial data centers
➢ SAS – Serial Attached SCSI - is a point-to-point serial protocol that moves data to and from computer-storage
devices such as hard drives and tape drives. With the use of expanders, 65,535 devices can connect to a
system.
➢ Serial Attach SCSI Specifications
SAS Specification
Throughput
SAS-1
3 Gbps
SAS-2
6.0 Gbps
SAS-3
12 Gbps
SAS-4
22.5 Gbps
➢ SAS SCSI connectors
➢ https://en.wikipedia.org/wiki/Serial_Attached_SCSI
➢ Tape Drive Specifications
Model/Specification
Capacity
Digital Linear Tape (DLT)
DLT = 40 GB, Super DLT = 110 GB
Linear Tape Open
LTO-1 = 100 GB, LTO-2 = 200 GB, LTO-3 = 400 GB, LTO-4 = 800 GB, LTO-5 = 1.5
TB, LTO-6 = 2.5 TB, LTO-7 = 6 TB, LTO-8 = 12 TB
Electrical Storage
Electrical Storage Characteristics
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https://smallbusiness.chron.com/features-solid-state-drives-81288.html
https://www.kingston.com/en/community/articledetail/articleid/48543
https://searchstorage.techtarget.com/definition/mSATA-SSD-mSATA-solid-state-drive
https://searchstorage.techtarget.com/definition/M2-SSD
https://www.tomshardware.com/reviews/glossary-m2-definition,5887.html
NVMe Specifications
➢ https://nvmexpress.org/resources/specifications/
➢ AHCI is used by SATA drives
➢ NVMHCI or Non-Volatile Memory Host Controller Interface (now just called NVMe or Non-Volatile Memory
Express) is the interface used in NVMe drives rather than AHCI which was built for traditional spinning
platter-based drives. NVMe reduces the request/transfer delay that is present in the SATA interface
➢ NVMe revisions
○ 1.3 (May 2017)
○ 1.4 (June 2019)<<<<<Current
➢ M.2 NVMe – this bus is provided via PCI Express 3.0 or PCI Express 4.0 with up to four lanes
PCI Express Revision
x1 (1 Lane)
x2
x4
PCI Express 3.0
984.6 MBps
1.969 GBps
3.94 GBps
PCI Express 4.0
1.969 GBps
3.938 GBps
7.88 GBps
PCI Express 5.0
still
in
draft
SATA Express (SATAe)
➢ Standardized as SATA 3.2, allows for both SATA and PCI Express bus interfaces.
➢ SATA Express (SATAe) – The SATA interface allows for 6 Gbps. PCI Express 2.0 and PCI Express 3.0 are available
for SATAe.
SATAe PCI Express
x1
x2
PCI Express 2.0
500 MBps
1 GBps
PCI Express 3.0
984.6 MBps
1.969 GBps
SDCard
➢ Storage capacities are defined by four names:
SDCard Name
Capacity
File System
SD
2 GB or less
FAT 12 or FAT 16
SDHC
2 GB – 32 GB
FAT 32
SDXC
32 GB – 2 TB
ExFAT
SDUC
2 TB – 128 TB
ExFAT
➢ SDCard Speeds are defined by three classes each with different ratings
➢ Speed Class, UHS Speed Class, Video Class
➢ https://www.sdcard.org/developers/overview/family/index.html
xD Cards
Type
Capacity
Read Speed
Write Speed
Standard
16 MB, 32 MB
5 MBps
1.3 – 3 MBps
Type M
64MB, 128 MB, 256MB, 512 MB
4 MBps
2.5 MBps
Type H
256 MB, 512 MB, 1 GB, 2 GB
5 MBps
4 MBps
Type M+
1 GB, 2 GB
6 MBps
3.75 MBps
➢ https://en.wikipedia.org/wiki/XD-Picture_Card
CompactFlash
Standard
Interface
Speed
CompactFlash 6.0
PATA – UDMA 7
167 MBps
CFast 1.0
SATA 2.0
300 MBps
CFast 2.0
SATA 3.0
600 MBps
CFExpress
PCI Express 3.0 x2
1.969 GBps
➢ CompactFlash Type I card = 3.3mm thick
➢ CompactFlash Type II card = 5 mm thick
MMC or MultiMediaCards
MMC Variant
Pins
Width
Height
Thickness
Capacity
MMC
7
24 mm
32 mm
1.4 mm
128 GB
RS-MMC
7
24 mm
18 mm
1.4 mm
2 GB
Optical Storage
Optical Formats
➢ Formats
Format
Writes
Reads
CD-ROM
No
Many
CD-R
Once
Many
CD-RW
Many
Many
DVD Formats
Format
Writes
Reads
DVD-ROM
No
Many
DVD-R
Once
Many
DVD-RW
Many
Many
Blu-ray Formats
Format
Writes
Reads
BD-ROM
No
Many
BD-R
Once
Many
BD-RE
Many
Many
Optical Capacities
CD – 700 MB
DVD – can have single-sided discs and double-sided disc with to writable sides (front and back)
DVD – can have single recordable data layer (single layer) or dual recordable data layers (dual layer)
The DVD+R DL specification is capable of storing the most data. It can hold up to 8.5 gigabytes (GBs) of data
because it writes to multiple layers on the disc. DVD-RW DL is a double-layer DVD drive that is rewritable,
meaning that it can be written to multiple times.
➢ DVD-R, DVD-RW, and DVD+RW can hold up to 4.7 GBs of data. The R designation means that data can be
recorded to the disc one time. The RW designation means that data is rewritable. The - designation specifies
that the format used by the disc is authorized by the DVD Forum. The + designation specifies that the format
used by the disc is not authorized by the DVD Forum.
➢ DVD-R discs are compatible with any DVD player, no matter what designation it is given.
➢ Blu-ray discs can currently hold up to 50 GBs of data. Standard Blu-ray discs hold 25 GB of data (50 GB if dual
layer). The newer BDXL format increases that capacity to 128 GB.
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Format
Capacity
DVD single-sided, single-layer
4.7 GB
DVD double-sided, single-layer
9.4 GB
DVD single-sided, dual-layer
8.5 GB
DVD double-sided, dual-layer
17 GB
➢ Like DVD, Blu-ray also can utilize multiple recordable data layers
Format
Capacity
Blu-ray single layer
25 GB
Blu-ray dual-layer
50 GB
Blu-ray BDXL
100 GB, 128 GB (BD-R) and 100 GB (BD-RE)
➢ CD have a base transfer speeds of 150 KBps with multipliers up to 52x
➢ DVD has a base transfer speeds of 1.385(1.4 MBps) with multipliers up to 24x
➢ Blu-ray has a base transfer speed of 4.5 MBps and multipliers up to 16x
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Configuring Storage
HDDs
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Sector – is the small unit of measurement on a HDD
Clusters(Allocation Units) – group of sectors, smallest unit allocated for file storage
Tracks – a concentric portion of the HDD that passes under a stationary read/write head
Cylinders – a collective set of tracks defined by all read/write heads in the assembly
SSDs
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SSDs perform page-level write operations and block-level erasure operations
When a page needs erased the entire block must be erased
SSDs cannot overwrite pages (HDDs can overwrite clusters at will) with existing data
Pages can contain:
○ No data – the page is ready for write operations
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Stale data – data that was modified. When data is “modified” the data and modifications are written to
new pages
Deleted data – data that has been marked as deleted by the operating system
Garbage Collection
➢ “Garbage collection involves having the controller search through its inventory of written pages for pages that
have been marked as “stale”—that is, they were written to and then the data they contained needed to be
modified by the OS; because changing the page’s state is impossible without first erasing it, the changes are
always written to new pages and the old pages marked stale. Garbage collection looks for blocks that contain a
mix of good and stale pages and then duplicates all the good pages into new blocks and leaves behind only stale
pages in the old block. Then it erases the old block and marks it ready for use.”
➢ https://getprostorage.com/blog/ssd-garbage-collection-trim/
TRIM Command
➢ “SSD TRIM is an Advanced Technology Attachment (ATA) command that enables an operating system to inform
a NAND flash solid-state drive (SSD) which data blocks it can erase because they are no longer in use. The use
of TRIM can improve the performance of writing data to SSDs and contribute to longer SSD life.”
➢ https://searchstorage.techtarget.com/definition/TRIM
File Systems
File System
File size (max.)
Volume size (max.)
FAT16
4 GB
4 GB
FAT32
4 GB
2 TB
exFAT
128 PB
16 EB
NTFS
16 TB
16 TB (default)
ext2
16 GB – 2 TB
2 TB – 32TB
ext3
4 TB – 32 TB
16GB – 2TB
ext4
16 TB
1 EB
APFS
8 EB
8 EB
HFS+
8 EB
8 EB
Troubleshooting Storage Resources
➢ http://www.buildcomputers.net/hard-disk-speed.html
➢ https://docs.microsoft.com/en-us/windows-server/storage/disk-management/troubleshooting-disk-managem
ent
➢ https://support.hp.com/us-en/document/c03458013
➢ https://www.windowscentral.com/how-troubleshoot-and-fix-external-drives-when-not-detected-windows-10
➢ https://www.computerhowtoguide.com/2014/08/hard-disk-problems-solutions.html
➢ https://www.technology-solved.com/chattanooga-tn/common-hard-disk-problems-and-solutions/
Motherboard
Form Factors Learner Resources
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https://www.lanner-america.com/blog/types-motherboard-form-factors/
https://www.webopedia.com/DidYouKnow/Hardware_Software/motherboard_form_factors.asp
https://computer.howstuffworks.com/motherboard1.htm
http://www.codesandtutorials.com/hardware/computerfundamentals/motherboard-types-form_factor.php
https://www.utilizewindows.com/types-of-computer-cases-and-motherboard-factors/
Form Factor
Manufacturer/Date
Dimensions
Standard-ATX Intel 1995
12 × 9.6 in
Workstation/Desktop
Micro-ATX
Intel 1997
9.6 × 9.6 in
Small Form Factor
Mini-ITX
VIA 2001
6.7 × 6.7 in
Small Form Factor
Nano-ITX
VIA 2003
4.7 × 4.7 in
Embedded Systems
Pico-ITX
VIA 2007
3.9 × 2.8 in
Embedded Systems
Mobile-ITX
VIA 2009
2.4 × 2.4 in
Embedded Systems
Connections
➢ PCI
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Applications
○ Version ----Speed
○ PCI 33 MHz, 32-bit 133 MBps
○ PCI 33 MHz, 64-bit 266 MBps
○ PCI 66 MHz, 32-bits 264 MBps
○ PCI 66 MHz, 64-bits 538 MBps
AGP
○ AGP 1.0 66 Mhz,266 MBps 1x
○ AGP 1.0 66 MHz, 533 MBps 2x
○ AGP 2.0 66 MHz, 1.06 GBps 4x
○ AGP 3.0 66 MHz, 2.133 GBps 8x
○ AGP 3.5 66 MHz, 2.133 GBps 8x
PCI-X
○ Version ----Speed
○ PCI-X 133 MHz 1.0 = 1.06 GBps
○ PCI-X 266 MHz 2.0 = 2.1 GBps
○ PCI-X 533 MHz 2.0 = 4.2 GBps
○ PCIe
Version ----Speed ----Lane --- Full bandwidth
PCIe 1.0 = 250 MBps 1x (500 MBps full duplex)
PCIe 1.0= 1 GBps 4x (2 GBps full duplex)
PCIe 1.0 = 2 GBps 8x (4 GB full duplex)
PCIe 1.0 = 4 GBps 16x (8 GB full duplex)
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PCIe 2.0 = 500 MBps 1x (1 GBps full duplex)
PCIe 2.0= 2 GBps 4x (4 GBps full duplex)
PCIe 2.0 = 4 GBps 8x (8 GB full duplex)
PCIe 2.0 = 8 GBps 16x (16 GB full duplex)
PCIe 3.0 = 1 GBps 1x (2 GBps full duplex)
PCIe 3.0= 4 GBps 4x (8 GBps full duplex)
PCIe 3.0 = 8 GBps 8x (16 GBps full duplex)
PCIe 3.0 = 16 GBps 16x (32GBps GB full duplex)
PCIe 4.0 = 2 GBps 1x (4 GBps full duplex)
PCIe 4.0= 8 GBps 4x (8 GBps full duplex)
PCIe 4.0 = 16 GBps 8x (16 GBps full duplex)
PCIe 4.0 = 32 GBps 16x (64 GBps full duplex)
PCIe 5.0 = 4 GBps 1x (8 GBps full duplex)
PCIe 5.0= 16 GBps 4x (32 GBps full duplex)
PCIe 5.0 = 32 GBps 8x (64 GBps full duplex)
PCIe 5.0 = 64 GBps 16x (128 GBps full duplex)
IO panel
➢ USB Speeds
○ USB 1.0 = 12 Mbps
○ USB 2.0 = 480 Mbps
○ USB 3.0 = 5 Gbps
○ USB 3.1 = 10 Gbps
➢ USB Device per port = 127 devices
➢ USB power = 5V
➢ Firewire (IEEE1394)
○ Firewire 400
■ 400 Mbps
■ 4-pin square-shaped (unpowered) connector
■ 6-pin bullet-shaped (powered) connector
○ Firewire 800
■ 800 Mbps
■ 9 pin square-shaped connector
○ Firewire devices per port = 63 devices
○ Firewire power = 12V
➢ S/PDIF
○ Digital audio
○ Copper transmission over coaxial RCA jacks and XLR connection
○ Optical transmission over TOSLINK cable
➢ Thunderbolt
○ Version 1.0
■ 10 Gbps (20 Gbps full duplex)
■ Cable length
● 10 ft for copper
● 200 ft for optical
■ Connector type = Mini DisplayPort
■ Connector pins = 20
○ Version 2.0
■ 20 Gbps(40 Gbps full duplex)
■ Cable length = same as Version 1.0
■ Connector type = Mini DisplayPort
○
■ Connector Pins = 20
Version 3.0
■ 40 Gbps (80 Gbps full duplex)
■ Cable length = same as Version 1 and 2
■ Connector Type = USB-C
■ Connector Pins = 24
➢ eSATA
○ Speeds follow the SATA standard
○ Cable length
■ Standard SATA cable is 3.28 ft or 1 m
■ eSATA cable increases this limit to 6.6 ft or 2 m
○ Used to connect the external storage
➢ TRS Audio Jacks
○ Analog audio
○ Colors
■ Pink: Mic in
■ Blue: Line in
■ Green: Front speakers out
■ Black (or dark blue on some older boards): Rear speakers out
■ Orange: Center/subwoofer out
■ Gray: Middle speakers out
Firmware
➢ Lenovo BIOS/UEFI Simulator
○ https://download.lenovo.com/bsco/index.html
➢ Firmware has traditionally been stored in three types of ROM (Read-only memory) chips
➢ PROM (Oldest type – Obsolete)
○ Programmable Read-only Memory
○ BIOS code stored in these chips could be programmed by the vendors.
○ Making it difficult to ensure the firmware was up to date
➢ EPROM (Older type – Obsolete)
○ Erasable Programmable Read-only Memory
○ BIOS code stored in these chips could be reset by removing the chip and shining a UV light into a glass
window on the chip
➢ EEPROM (Currently used to store BIOS/UEFI instructions)
○ Electrically Erasable Programmable Read-Only Memory
○ BIOS/UEFI settings stored in these chips are reset/reprogrammed via an electrical current sent across
the integrated circuit (motherboard). The benefits of these chips is that they do not have to be
removed from the motherboard. Software can control the reprogramming in the form of “firmware”
updates.
➢ https://www.wikihow.com/Change-Computer-BIOS-Settings
➢ https://www.lifewire.com/bios-settings-831400
➢ https://www.pcgamer.com/how-to-a-guide-to-bios-settings/
➢ https://www.pcgamer.com/ultimate-bios-guide-every-setting-decrypted-and-explained/
➢ https://www.maketecheasier.com/common-bios-settings/
➢ https://www.pcworld.com/article/241032/how-to-enter-your-pcs-bios.html
➢ CMOS (Complementary Metal Oxide Semiconductor):
○ Holds configuration settings
○ Provides real-time Clock
○ Uses CR2032 3V battery
➢ BIOS uses master boot record, UEFI uses GPT
○ UEFI allows for greater security, and greater drive size
➢ Motherboard Settings:
○ Firmware versions
○ System Date and Time
○ CPU type and speed
○ Installed memory
○ Network settings
○ Voltages
○ Keyboard and mouse
○ Drive interfaces
○ Boot order
○ Virtualization
➢ BIOS/UEFI Security:
○ User Password and Supervisor Password. Supervisor password can reconfigure BIOS/UEFI settings,
user password cannot
○ Drive Encryption can be done in BIOS/UEFI
○ Secure Boot is UEFI ONLY! not in BIOS
○ Trusted Platform Module (TPM)- Security processor integrated into the motherboard, stops computer
from booting if things are added that it does not recognize
○ LoJack - GPS tracking of computer if stolen
Cooling Systems
Cooling Learner Resources
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https://www.pcgamer.com/pc-cooling-basics/
https://dealna.com/en/Article/Post/722/Types-of-Computer-Cooling-Systems-Which-to-Choose
https://www.howtogeek.com/192196/5-cooling-solutions-to-prevent-your-pc-from-overheating/
https://medium.com/computing-technology-with-it-fundamentals/system-hardware-component-cooling-syst
em-in-a-computer-7d8602523c4a
https://techpp.com/2012/09/25/how-to-choose-pc-cooling-system/
CPUs generate large amounts of heat
Heat can cause major system damage
Overheating causes system failure
Fans:
○ Move hot air away from system parts
○ Characteristics: Size, RPMS, CFMS, Noise level
○ Connectors: 3 pin kk connector, 4 pin kk connector, 4 pin molex connector
Heat Sinks:
○ Increases CPU Surface area
○ Dissipates heat away from the processor
○ Cooling types:
■ Passive Cooling- No fan, low power situations, not as much heat, chipsets, nano ITX
■ Active Cooling - Fan assisted cooling, most CPUs use this, greater heat dissipation
Thermal Compound:
○ Bridges the gap between CPU and heat sink, does not allow a gap to exist between CPU and heatsink
○ Essential for heatsink to function properly
Liquid Cooling:
○ Silent cooling
○ Hoses, fittings, pumps, ethylene glycol
Power Supply Units
Power Learner Resources
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https://computer.howstuffworks.com/power-supply.htm
https://www.makeuseof.com/tag/power-supplies-explained-pick-perfect-psu-computer/
https://www.pcworld.com/article/456490/how-to-pick-the-best-pc-power-supply.html
https://centralvalleycomputerparts.com/articles/power-supply-specifications-explained/
https://www.tomshardware.com/reviews/power-supplies-101,4193.html
PSU converts AC power to DC power, performs voltage regulation
Considerations:
○ Wattage is important when buying a PSU
○ Form Factor
○ Connectors
Fixed Input PSU - Dedicated switch to manage voltage that is manually configured
Auto-Switching PSU
Input Voltages:
○ 110V (USA)
○ 220V (Everywhere else)
○ Dual Voltage PSU
Power output:
○ 3.3V
○ 5V
○ 12V
○ The Power Good signal is a +5 voltage sent over a specific wire in the connector. This wire sends power
from the power supply to the motherboard. If the motherboard does not receive the signal, the
computer will not boot. If this is occurring, the only solution is to replace the power supply. The +5
voltage provides power to the motherboard. It also provides power to older CD/DVD drives, hard
drives, PCI cards, and Pentium III and earlier processors
○ The +3.3 voltage provides power to certain video cards and the motherboard. However, it has nothing
to do with the Power Good signal
○ The -5 voltage provides power to the ISA or AT bus adapter cards.
○ The -12 voltage provides power to some older network adapters and serial ports
○ The +12 voltage provides power to newer CD/DVD drives, hard drives, and Pentium 4 and Athlon
processors
○ A Molex connector is the power connector that is larger than the connector used for floppy diskette
drives, and it is commonly used with PATA drives. A Berg connector is used with floppy disk drives
Form Factors of PSU:
○ Original ATX standard used 20 pin keyed locking connector
■ ATX12V 1.x brought in the 20+4 connector
■ ATX12V 2.0 Brought in the 24 connector supports PCIe
○ EPS12V
■ Server side power and is backwards compatible with ATX12
■ Often Implemented as two 4 pin connectors
P4 12v CPU power connector was part of the ATX12v 1.x standards for the pentium 4 processors
ATX 12v CPU power connector 8 pin connector was part of the ATX12V 2.0 standard powers multi core CPU
SATA Connector
○ 15 pins
○ L-shaped connector
Molex Connector
○ 4 pin connector
○ System Fans
➢ PCI Express
○ 6 pins
○ 6+2 pins
○ 8 pins
Troubleshooting Cooling and Power
Cooling
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➢
https://www.hongkiat.com/blog/cool-down-heating-pc/
https://www.dell.com/support/article/us/en/04/sln113205/how-to-troubleshoot-fan-issues?lang=en
https://www.howtogeek.com/174288/how-to-tell-if-your-computer-is-overheating-and-what-to-do-about-it/
https://www.wikihow.com/Fix-Computer-Overheating-Caused-by-Blocked-Heat-Sink
https://pcpluglife.com/fix-cpu-overheating/
https://www.domstechblog.com/overheating-computer-causes-and-solutions/
Power
➢ CAUTION NEVER OPEN POWER SUPPLIES, IF DAMAGED REPLACE
➢ http://www.informit.com/articles/article.aspx?p=31105&seqNum=12
➢ https://www.dell.com/support/article/us/en/04/sln285154/how-to-troubleshoot-a-no-power-issue-on-your-de
ll-desktop?lang=en
➢ https://www.pcmag.com/how-to/what-to-do-when-your-computer-wont-start
➢ http://www.linuceum.com/Hardware/hwPrbPSU.php
➢ External Power Issues
○ Line noise
○ Power sag
○ Undervoltage or brownout
○ Frequency Variations
○ Overvoltage
○ Power Failure
➢ Internal Power Issues
○ Fans do not work usually happens if they are clogged
○ No power
○ UPS (uninterruptible power supply) makes sure system shutdown properly when power goes out
○ Fans spin, no device power
○ Computer reboots
○ Burning smells
○ Smoke coming from the computer
○ Loud noise coming from the power supply
Memory
➢ Single inline memory module (SIMM)
➢ Rambus dual inline memory modules (RIMM)
○ Required continuity blanks called C-RIMMS
➢ Continuity Rambus inline memory modules (C-RIMM)
➢ Dual inline memory module (DIMM)
➢ Small outline dual inline memory module (SODIMM)
○ Found in laptops
➢ Micro dual inline memory module (MicroDIMM)
○ Found in laptops
➢ Dynamic random access memory(DRAM)
○ Not synchronized with system clock
○ Slow
➢ Synchronous dynamic random access memory (SDRAM)
○ Synchronized with the system clock
○ Faster than DRAM
➢ Single data rate (SDR SDRAM) or SDRAM
➢ Retro named standard (Legacy)
➢ Double data rate (DDR SDRAM)
○ 184 pins
100 – 200 MHz
○ 2.6 V, 2.5 V
➢ Double data rate 2 (DDR2 SDRAM)
○ 240 pins
200 – 400 MHz
○ 1.8 V, 1.55 V
○ 4 GB memory modules
➢ Double data rate 3 (DDR3 SDRAM)
○ 240 pins
○ 8 GB memory modules
400 MHz – 1066 MHz
○ 1.5 V, 1.35 V
➢ Double data rate 4 (DDR4 SDRAM)
○ 288 pins
○ 64 GB memory modules
800–1600 MHz
○ 1.2V
Memory Standard
Speed
Format
DDR500
4,000 MBps
PC4000
DDR533
4,266 MBps
PC4200
DDR2-667
6,000 Mbps
PC2-5300
DDR2-800
6,400 MBps
PC2-6400
DDR3-800
6,400 MBps
PC3-6400
DDR3-1600
12,800 MBps
PC3-12800
DDR4-1866
14,933 MBps
PC4-14900
DDR4-2133
17,067 MBps
PC4-17000
DDR4-2666
21,333 MBps
PC4-21333
DDR4-3200
25,600 MBps
PC4-25600
SODIMM Standards
Standard
Pins
SDR SDRAM
100 pins
SDR SDRAM
144 pins
DDR SDRAM
200 pins
DDR2 SDRAM
200 pins
DDR3 SDRAM
204 pins
DDR4 SDRAM
260 pins
UniDIMM
260 pins
MicroDIMM Standards
Standard
Pins
SDR SDRAM
144 pins
DDR SDRAM
172 pins
DDR2 SDRAM
214 pins
➢ Memory can be volatile or non-volatile
○ RAM is volatile memory, it requires power. If power is lost all data will be lost on volatile memory
○ NVRAM and ROM non-volatile memory, does not require power to keep data stored. BIOS is stored here
➢ Parity
○ Used as an error detection method
○ Adds a parity bit to every 8 bits data (1 byte)
○ Even and Odd Types
➢ ECC
○ Error-code Correction
○ Server-level
○ Expensive
○ Compatibility issues
➢ Memtest86+
○ https://www.memtest.org/
➢ Windows Memory Diagnostic Toolkit
○ https://docs.microsoft.com/en-us/previous-versions/technet-magazine/cc745953(v=msdn.10)?redirec
tedfrom=MSDN
Troubleshooting Memory
http://www.centon.com/support/54-ram-memory-troubleshooting
https://www.flexxmemory.co.uk/pages/help/troubleshooting-memory-problems.html
https://www.ifixit.com/Wiki/Troubleshooting_Computer_Memory
https://www.crucial.com/usa/en/support-install-memory-troubleshooting
https://www.streetdirectory.com/travel_guide/156663/computer_troubleshooting/step_by_step_troubleshoo
ting_ram.html
➢ http://www.informit.com/articles/article.aspx?p=1416688&seqNum=10
➢ Common Issues:
○ Unsuccessful POST:
○ Improperly seated module
○ BIOS/UEFI settings
○ ECC vs Non-ECC
○ Reboots:
○ Overheating
○ Misconfigured BIOS UEFI
○ Improperly seated module
○ ESD damage
○ Module Failure
○ System Lockups
○ Frozen system
○ Misconfigured BIOS/UEFI System
○ Improperly seated module
○ Module failure
○ Slow Performance
○ Limited memory capacity
○ Mismatched memory
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CPU Features & Characteristics
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https://www.indiastudychannel.com/resources/152510-Features-of-a-Central-Processing-Unit-CPU-.aspx
https://www.pcworld.com/article/221559/cpu.html
https://www.ifixit.com/Wiki/Computer_Processor_Characteristics
Brains of the system unit
Performs all calculations
Positioned on the system bus. System bus has these names:
○ Front-side bus (generic)
○ Intel-Quickpath Interconnect (QPI)
○ AMD- HyperTransport
CPU Architecture:
○ 32-bit and 64-bit
Single CPU vs Multiple CPUs
○ Multiple CPU support:
○ Intel-Xeon
○ AMD- Opteron
○ AMD-EPYC
Multicore Processors
○ More than one processing unit on one CPU
Clock speed:
○ How many calculations a CPU can perform in a given amount of time
CPU speed:
○ How fast the instructions are sent across the system bus
Overclocking:
○ Increase CPU speed by applying higher voltage, dangerous
Throttling:
○ Reduce voltage to CPU to slow down the processor. Conserve battery life
Hyperthreading
○ Intel ONLY
○ A way to overlap instructions and send instructions to a single core within a multicore processor
○ Performance increase of 30%
○ Sending more than one instruction to the CPU. Doubles cores. 4 cores = 8 cores
Cache:
○ Small amount of RAM for recently used instructions inside the CPU
○ L1, L2 cache
○ Makes CPU much faster
○ SRAM
Virtualization support:
○ CPU must support virtualization
○ Intel VT-x
○ AMD-V
○ Second level Address Translation (SLAT) increases performance
■ Intel - Extended Page Tables (EPT)
■ AMD - Rapid Virtualization Indexing (RVI)
Voltage Regulator Modules (VRM)
○ Regulates voltage to the CPU. Embedded into the motherboard
○ CPU operates on a 1.5V
Multimedia Extensions:
○ Intel - MMX
○ AMD 3DNow!
○ Additional instructions included so CPU can have video sound etc
➢ Execute Disable bit (EDB)
○ Intel- XD bit
○ AMD - Enhanced Virus Protection
○ NX bit
○ Security feature that prevents execution on programs in certain sections of memory
➢ Integrated GPU
○ Put graphics processing unit into CPU
○ Intel - HD graphics series
○ AMD - Vega
➢ Overclocking
○ You can specifically overclock the processor, RAM, and system bus. No other computer components
can be overclocked. However, overclocking the system bus may also cause other components to be
overclocked. Overclocking allows you to run the processor or system bus at a higher speed than the
manufacturer's rating to gain increased performance.
Form Factors
➢ PGA
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➢ LGA
Pin grid Array
ZIF (zero insertion force) socket
Integrated Circuit
Through hole method
Socket 603 – Intel Xeon
■ https://en.wikipedia.org/wiki/Socket_603
Socket 754 – AMD Athlon 64
■ https://en.wikipedia.org/wiki/Socket_754
Socket 939 – AMD Athlon 64
■ https://en.wikipedia.org/wiki/Socket_939
Socket 940 – AMD Athlon 64 & Opteron
■ https://en.wikipedia.org/wiki/Socket_940
Socket AM2 – AMD Athlon 64 series
■ https://en.wikipedia.org/wiki/Socket_AM2
Socket AM2+ - AMD Athlon 32, Athlon 64 x2, Phenom, Phenom II
■ https://en.wikipedia.org/wiki/Socket_AM2%2B
Socket AM3 – AMD AMD Phenom II, Athlon II, Sempron
■ https://en.wikipedia.org/wiki/Socket_AM3
Socket AM3+ - AMD FX Vishera, AMD FX Zambezi, AMD Phenom II, AMD Athlon II
■ https://en.wikipedia.org/wiki/Socket_AM3
Socket AM4 – AMD Ryzen
■ https://en.wikipedia.org/wiki/Socket_AM4
Socket P – Intel Core2
■ https://en.wikipedia.org/wiki/Socket_P
G1/G2/rPGA 988A/B – Intel Core iSeries (all)
■ https://en.wikipedia.org/wiki/Socket_G1
■ https://en.wikipedia.org/wiki/Socket_G2
Socket FM1 – AMD A-series
■ https://en.wikipedia.org/wiki/Socket_FM1
Socket FM2 – AMD Trinity Processors
■ https://en.wikipedia.org/wiki/Socket_FM2
Socket FM2+ - AMD Kaveri
■ https://en.wikipedia.org/wiki/Socket_FM2%2B
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➢ BGA
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Land grid array
Integrated circuit
Surface mount packaging
LGA 775 (Socket T) – Intel Core 2 Duo, Quad
■ https://en.wikipedia.org/wiki/LGA_775
■ LGA 775 sockets also support Pentium 4, Celeron, Pentium 4 Extreme Edition, Core 2 Quad, and
Xeon processors
LGA 1366 (Socket B) – Intel Core i7, i5, Xeon
■ https://en.wikipedia.org/wiki/LGA_1366
LGA 1156 (Socket H) – Intel Core i7, i5, Xeon, Pentium
■ https://en.wikipedia.org/wiki/LGA_1366
LGA 1155 (Socket H2) – Intel Celeron, Core Series (all), Pentium
■ https://en.wikipedia.org/wiki/LGA_1155
■ An LGA 1155 CPU socket supports Core i3/i5/i7, Pentium, Celeron, and Xeon CPUs
LGA 1150 (Socket H3) – Intel Core Series
■ https://en.wikipedia.org/wiki/LGA_1150
LGA 1151 (Socket H4) – Intel Celeron, Core Series, Pentium
■ https://en.wikipedia.org/wiki/LGA_1151
LGA 2011 (Socket R) – Intel i7, Xeon
■ https://en.wikipedia.org/wiki/LGA_2011
LGA 2066 (Socket R4) – Intel i5, i7, Xeon
■ https://en.wikipedia.org/wiki/LGA_2066
Ball Grid Array
Surface-mount technology
Integrated
Used in chipsets and mobile CPUs
Display Devices
➢ Output devices that displays information received from a graphics card
➢ Various Types
○ LCD (Liquid Crystal Display)
○ LED (Light Emitting Diode)
○ OLED (Organic Light Emitting Diode)
➢ LCD
○ Flat panel display
○ Thinner and brighter that CRT tech
○ Used backlighting
➢ LED
○ Flat panel display
○ Thinner than LCD
○ Use the same tech as LCD
○ Backlighting
■ WLED
● White LED
■ RGB LED
● Red Green Blue LED
➢ OLED
○ Organic electroluminescent compound
○ Very thin and flexible
○ Low power
○ Mobile devices
➢ LCD Display Technologies
○ Passive Matrix
■ Uses rows of transistors
■ Less power required compared to active matrix
■ Slower refresh rates
■ Lower image quality
■ Dimmer image than active matrix
■ Narrow viewing angle
○ Active Matrix
■ Also called Thin-Film transistor (TF)
■ Each pixel has a transistor
■ Faster refresh rate
■ Brighter Image
■ Requires more power
○ Twisted Nematic
■ Older LCD tech
■ Cheapter
■ Uses nematic liquid crystal
■ Fast response times
■ Restricted viewing angles
○ In-Plane Switching
■ Uses liquid crystals in parallel
■ Better viewing angle than TN displays
■ Excellent color accuracy
■ Susceptible to motion blur
■ Slower response times than TN screens
○ Backlighting
■ Fluorescent
● Older tech used CCFL (cold cathode fluorescent lamps) and single straight glass tube
● Thicker than LED backlight screens
■ Full array light emitting diode
● Array of LEDs arranged in a uniform pattern
● Array spans entire back of the screen
■ Edge light emitting diode
● Array spans edges of the screen
● Smaller, dimmer compared to full array LED
Cables and connections
➢ Several cables and connectors are used for display devices
➢ Standardization
➢ Characteristics
○ Name
○ Shape
○ Gender
➢ Display Connections Types
○ Video Graphics Array (VGA)- https://en.wikipedia.org/wiki/VGA_connector
○ Digital Visual Interface (DVI)- https://en.wikipedia.org/wiki/Digital_Visual_Interface
○ High Definition Multimedia Interface (HDMI) - https://en.wikipedia.org/wiki/HDMI
○
○
○
○
○
○
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➢ VGA
○
○
○
➢ DVI
○
○
DisplayPort - https://en.wikipedia.org/wiki/DisplayPort
Component video - https://en.wikipedia.org/wiki/Component_video
Composite video - https://en.wikipedia.org/wiki/Composite_video
RCA - https://en.wikipedia.org/wiki/RCA_connector
S-Video (Separate video) - https://en.wikipedia.org/wiki/S-Video
Coaxial - https://en.wikipedia.org/wiki/Coaxial
Bayonet Neill–Concelman (BNC) - https://en.wikipedia.org/wiki/BNC_connector
Also known as DB-15
15 pins
Analog video output
Digital video and analog varieties
Variants:
■ DVI-A
● Analog only
■ DVI-I
● Integrated, supports digital and analog (18 pin)
■ DVI-D
● All digital interface (24 pin)
➢ HDMI, Mini-HDMi, Micro-HDMi
○ 19-pin connector
○ Digital audio and video
○ 50 ft cable lengths
○ Supports multiple modes
■ SDTV
■ HDTV
■ EDTV
➢ DisplayPort, Mini-DisplayPort
○ Digital audio and video single cable
○ 20 pin connector
○ Royalty free
➢ Component Video
○ Carries analog video
○ 3 connections
➢ Composite Video
○ Analog video
○ Standard definition
➢ RCA
○ Radio corporation of America
○ Carries analog video
○ Left and right audio
➢ S-Video (separate video)
○ 480i or 576i modes
○ miniDIN-4 connector
➢ Coaxial
○ Shielded cable with copper conductor
○ Shield increases resilience to electromagnetic interference
○ Copper conductor
■ Solid
■ Braided
○ Must have matching resistance
■ 50 Ohms
■ 75 Ohms
➢ Bayonet-Neil Concelman (BNC)
○ Twist-to-lock connector
○ Terminates coaxial cables
➢ Adapters
○ DVI to HDMi
○ DVI to VGA
○ Thunderbolt to DVI
○ HDMi to VGA
Display Device Features
➢ Display Resolutions, Aspect Ratios and hyperlinks for more information
Standard
Aspect
ratio
Width (px)
Height
(px)
SVGA
4:3
800
600
XGA
4:3
1024
768
WXGA
16:9
1280
720
WXGA
16:10
1280
800
SXGA
5:4
1280
1024
Standard
Aspect
ratio
Width (px)
Height
(px)
SVGA
4:3
800
600
XGA
4:3
1024
768
HD
≈16:9
1360
768
HD
≈16:9
1366
768
WXGA+
16:10
1440
900
HD+
16:9
1600
900
WSXGA+
16:10
1680
1050
FHD
16:9
1920
1080
WUXGA
16:10
1920
1200
QWXGA
16:9
2048
1152
QHD
16:9
2560
1440
4K UHD
16:9
3840
2160
➢ Shoulder surfing - the practice of spying on the user of an ATM, computer, or other electronic device in order to
obtain their personal access information.
➢ https://www.lifelock.com/learn-identity-theft-resources-what-is-shoulder-surfing.html
➢ Resolution:
○ The number of pixels that make up the dimensions of the display
○ Written width by height
○ Resolutions follow different standards
➢ Aspect Ratio:
○ A ratio of width of height of the display
○ Common aspect ratios:
■ 4:3
■ 16:9
■ 16:10
➢ Native Resolution
○ Only support for a single resolution on the monitor
○ Fixed resolution
○ LCD and LED monitors
○ Requires the signal input and native resolution to be the same
➢ Refresh Rate
○ Number of times the screen is redrawn
○ Measure in Hertz
○ Applies to CRT monitors
○ No need to adjust LCD/LED displays
➢ Brightness
○ Amount of brightness emitted from the display
○ Measured in lumens
➢ Analog vs Digital
○ Analog
■ VGA
■ DVI-A
■ DVI-I
■ Composite
■ Component
■ S-video
○ Digital
■ HDMi
■ DVI-I
■ DVI-D
■ DisplayPort
➢ Privacy and Anti-Glare
○ Reduces glare
○ Screen protection
○ Reduces successful shoulder surfing
➢ Color Depth
○ Number of bits used to represent the color of pixel
○ Common color depths
■ 8-bit (color) 256 colors
■ 16-bit 2^16
■ 24-bit 2^24
■ 32-bit 2^32
➢ Contrast Ratio
○ A ratio that expresses the difference in luminance between the white and black
○ Higher contrast ratio is desired
➢ Multiple Display
○ Multiple connections signal graphics adapter
Common display issues
➢ Dark screen
○ Power indicator lights?
○ General power problems
○ Surge protector
○ UPS
○ Circuit breaker
➢ Dim image on the screen
○ Connections
○ Brightness settings
○ Contrast settings
○ Power saving mode
➢ Display turns itself off
○ Power saver settings
○ Video card overheating
○ General overheating issues
➢ Application issues
○ Flickering
○ Erratic behavior
○ Application could required different:
■ Resolution
■ Color depth
➢ Defective pixels
○ Damage to the display/monitor
○ Two types:
■ Dead pixel - not fixable
■ Stuck pixel - fixable
➢ Color issues
○ Incorrect tint adjustment
➢ Physical damage
○ Repairs may not be possible
○ Check for vendor warranty
➢ Distorted geometry
○ Resolution settings
➢ Burn-in
○ More prevalent on older CRT monitors
○ Less likely on LCD/LED monitors
➢ Over-sized images
○ Resolution settings
➢ Video card issues
○ Boots to VGA mode
○ Visual artifacts
○ Distortions
○ BSOD
Expansion Cards
➢ The word cards and adapters are synonymous
➢ Expansion cards - https://techterms.com/definition/expansioncard
➢ Sound Cards - https://www.computerhope.com/jargon/s/souncard.htm
○ Receives audio inputs
○ Translates in audio output
○ Microphones- input
○ Speakers- output
➢ Video Cards - https://en.wikipedia.org/wiki/Video_card
○ Generates visual output
○ Can support multiple connection types
➢ Network Cards (Network Interface Cards) - https://simple.wikipedia.org/wiki/Network_card
○ Provides network communications
○ Can support different connections
■ Copper Ethernet (RJ-45)
■ Fiber Ethernet (SC, ST)
○ Contains a transceiver chips
➢ FireWire Cards - https://www.techwalla.com/articles/what-is-a-firewire-card
➢ Thunderbolt cards https://www.macworld.com/article/1158145/thunderbolt_what_you_need_to_know.html
➢ Modem cards - https://www.techopedia.com/definition/25901/modem-card
○ Allows for RJ-11 dial-up connections
➢ Wireless Cards - https://www.pcmag.com/encyclopedia/term/56199/wireless-adapter
Computer Cases
https://www.pcmag.com/news/buying-a-pc-case-20-terms-you-need-to-know
http://www.buildcomputers.net/computer-case-sizes.html
https://www.lifewire.com/what-is-a-computer-case-2618149
https://www.hackint0sh.org/computer-case-sizes/
https://www.pchardwarehelp.com/case.php
https://www.computer-hardware-explained.com/what-is-a-computer-case.html
Case Sizes
○ Full Tower 22 inches height or more, 6-10 externally accessible drive bays
○ Mid tower 18 inches, 2-4 externally accessible drive bays
○ Mini tower 1-2 externally accessible drive bays
○ Micro tower No externally accessible drive bays
○ Slimline Case thinnest of the cases
➢ Front panel headers
○ Power switch
○ Power light
○ Hard drive activity
○ Reset switch
○ Audio
○ USB
➢ Common Issues
○ Dust
○ Connections
○ Operating Environment
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Custom PC
➢ Graphic/CAD/CAM design workstation
○ Computer aided design
○ Computer assisted machinery
○ SSD
○ High-end video
○ Maximum RAM
➢ Audio/video editing workstation
○ Specialized audio and video cards
○ Large, fast hard drive
○ SSDs
○ RAID
○ Dual monitors
➢ Virtualization Workstation
○ Maximum RAM
○ More than one operating system
○ CPU Cores
➢ Gaming PC
○ SSD
○ RAID
○ High-end video GPU
➢ Network Attached Storage Device (NAS)
○ Media streaming
○ File sharing
○ Gigabit NIC
○ RAID array
➢ Standard thick client
○ Standard workstation
○ Supports desktop applications
○ Meets recommended requirements for selected OS
➢ Thin Client
○ Basic applications
○ Meets minimum requirements for OS
○ Network connectivity
Hardware Troubleshooting
➢ Unexpected shutdowns – Random shutdowns that are not accompanied with a particular error message are
usually the result of overheating. Make sure that all fans are working effectively. You may also want to deploy
additional cooling options. Make sure that all open ports in the computer have a cover. If an unexpected
shutdown is accompanied by a blue screen of death (BSOD), please refer to the BSOD section below.
➢ System lockups – System lockups occur when the system mysteriously stops functioning and no error or BSOD
is displayed. Examine the system log files to troubleshoot the issue. Usually system lockups are due to
memory issues, viruses, malware, or video issues.
➢ POST beep codes – When a system boots, the power-on self-test (POST) will check the devices for functionality.
If a device fails during the POST, a series of beep codes will sound to indicate the problem. The codes that are
used vary based on the manufacturer of the BIOS. An A+ technician should be familiar with the beep codes of
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the major BIOS manufacturers or know how to locate the beep codes. Keep in mind that one short beep
means that the system is operational.
Blank screen on bootup – For this issue, always test the obvious. Usually a blank screen is a video device
problem. Make sure the monitor is plugged in to the wall socket, plugged in to the computer, and turned. It
may also be necessary to test the wall outlet. You may also need to verify that the computer is plugged in to
the wall socket and turned on. Finally, you may want to replace the video card with a known good video card.
If you hear the system fan but the computer is not making the POST beep sound, you may have a failed
motherboard.
BIOS times and settings reset – If you encounter this issue, the problem is with the CMOS battery. Replace the
CMOS battery and make sure to reset your BIOS settings.
Attempts to boot to an incorrect device – This issue is usually related to the BIOS boot order. It was more
common when floppy drives were listed as the first boot device. If a non-bootable floppy were left in the floppy
drive at boot time, the computer would display a non-system disk or disk error at startup. Once the floppy disk
was removed from the drive, the computer would boot. Today, a CD-ROM or DVD drive is often listed as the first
boot device. You can change the boot order in the BIOS. This issue can also result from missing or corrupt boot
files. If you suspect that this error is due to boot files being missing or corrupt, you should enable boot logging
from the Windows Advanced Menu and replace the missing or corrupt boot files using the Windows installation
DVD.
Continuous reboots – Reboots are usually the result of electrical issues, power supply issues, or overheating.
Brownouts or blackouts cause computers to reboot. Attaching a computer to an uninterruptible power supply
(UPS) will ensure that you can safely shut down the computer if these occur. If the power supply in the
computer is the issue, you should replace it with one that supplies adequate power to the computer. Finally, if
overheating is causing the reboots, you should check all fans and ensure that the CPU heat sink is still
attached. You may need to replace these or add another cooling device to your computer.
No power – Once again, check the obvious. Make sure that the computer is plugged in and that the wall outlet
is supplying power. If a UPS or surge protector is used, check to see if its breaker was tripped by a power surge.
Finally, check the computer's power supply by replacing it with a known good unit.
Overheating – This is usually the result of cooling fan or cooling system failures. Make sure that all open slots
are covered. In addition, ensure that all system fans are functional.
Loud noise – Loud noise is usually caused by system fans, the power supply, or the hard drives because very
few internal devices have moving parts. Check those three devices to trace the noise. Replace the part that is
making the noise because the noise usually means that the device is close to failure.
Intermittent device failure – First, make sure that you have the latest driver for the device. If the problem
persists, you should replace the device. If intermittent failures are occurring with different devices, you could
have a motherboard that needs replacing.
Fans spin, no power to other devices – If no beep codes are heard, you probably have motherboard failure. If
you hear beep codes, record the code that is heard and research that code to find the problem device. This
problem could also mean that the power supply was not properly plugged into the motherboard.
Indicator lights – Many components in a computer have indicator lights. In most cases, indicator lights will
blink when activity is occurring and will be steady green when idle. However, some devices will have other
lights and/or colors. Always consult the vendor documentation. If problems continue, you should replace the
device.
Smoke – This is a horrible problem to have but is usually easy to trace. Shut down the computer immediately
and locate the device that is producing the smoke. Replace that device.
➢ Burning smell – This problem usually accompanies smoke. As with smoke, you should shut down the
computer immediately and locate the device that is producing the smoke. Replace that device.
➢ Proprietary crash screens (BSOD/pinwheel) – Windows Blue Screen of Death (BSOD) errors are usually the
result of hardware issues. You should always replace hardware one device at a time, followed by a system
boot. If the new hardware did not fix the issue, then that component is not the issue. Replace the component
with the original and try replacing another component. Some of the more common BSOD errors are listed
below:
➢ Data_Bus_Error – Faulty hardware has been installed or existing hardware has failed. Usually this error is
related to RAM, cache, or video RAM.
➢ Unexpected_Kernel_Mode_Trap – Remove or replace any recently installed hardware. Run hardware
diagnostics to determine which component has failed. Replace the failed hardware. This error can also be
caused if you set the CPU to run at a higher speed than the CPU supports.
➢ Page_Fault_in-nonpaged_area – This error is caused by RAM, cache, or video RAM. Replace the failed
component.
➢ Irq1_not_less_or_equal – This issue is usually caused by a device driver, system service, virus scanner, or
backup tool that is not compatible with the version of Windows you are running. Make sure that all your
drivers and software is updated to the version that is compatible with the Windows OS you are using.
➢ Pinwheel errors occur when users see the spinning rainbow pinwheel. Causes include bugs in applications,
event processing issues, and virtual memory issues.
➢ Distended capacitors – Capacitors are included in computers on the motherboards, video cards, and power
supplies. Capacitors can fail prematurely, causing the capacitor's case to bulge or rupture. In most cases, the
only way to fix this problem is to replace the card that has the swollen capacitor. It is possible to replace them,
but the process requires soldering experience. Replacing the capacitor is an electrical hazard and should only
be attempted with proper training.
Peripherals
Common peripherals
➢ Game controllers Camera/webcam
➢ Microphone
➢ Speakers Headset
➢ Printer Monitors
➢ Optical drive types
➢ Mouse
➢ Keyboard
➢ ADF/flatbed scanner
○ Auto document feed
○ Usually apart of the printer
○ Photo quality copies
○ Components
■ Stepper motors
■ Scanning assembly
○ Graphical input device
➢ Barcode scanner/QR scanner
○ Used to read input codes to identify products
○ Uses serial or USB connections
○ Input device
➢ VR headset
○ USB and HDMI
○ Graphical Output device
➢ KVM switch
○ Keyboard Video Mouse
○ Control multiple PCS from a single switch
○ Can be found in large data centers
○ Input and output device
➢ Magnetic reader/chip reader
○ Electronic transactions
○ Credit and debit cards
○ Serial and USB connections
➢ NFC/tap pay device
○ Near-field communications
○ 20 cm range
○ Transfer rate .424 Mbps
○ USB connections
○ Input device
➢ Smart card reader
○ Authentication mechanisms
○ Stores credentials
○ Plastic card
○ Input device
➢ Touchpad vs. signature pad
○ Embedded into laptops
○ Input device
○ USB connections
○ Signature pad is a special touchpad used in point of sale systems
➢ Projector
○ Output device
○ Connections:
■ VGA, DVI, HDMi, Displayport
■ Lumens/brightness
➢ External storage drives
○ Removable devices
○ Increase storage capacity
○ Input and output device
Laptop Hardware and Features
➢ http://www.laptoptips.ca/hardware/
➢ https://www.overstock.com/guides/laptop-components-explained
➢ https://www.dummies.com/consumer-electronics/tablets/for-seniors-understand-laptop-hardware-and-softw
are/
➢ Keyboard is an integrated component connected via a ribbon cable
○ Fewer keys than external keys
○ Fn key is used to access additional features
➢ Laptop Drives
○ SSD
Hybrid (mix of SSD and HDD)
Magnetic
■ Lower RPMS
■ 4200 RPM
■ 5400 RPM
○ Form Factor
■ 1.8” (Toshiba)
■ 2.5” (most common)
Laptop Memory
○ SODIMM
■ SDR SDRAM = 100 pins
■ SDR SDRAM = 144 pins
■ DDR SDRAM = 200 pins
■ DDR2 SDRAM = 200 pins
■ DDR3 SDRAM = 204 pins
■ DDR4 SDRAM = 260 pins
○ MicroDIMM
■ SDR SDRAM = 144 pins
■ DDR SDRAM = 172 pins
■ DDR2 SDRAM = 214 pins
Smart Card Reader
○ Authentication mechanism
○ Integrated vs peripheral
Optical drives in a laptop
○ Thinner/smaller than desktop
○ CD, DVD, Blu-ray
Wireless card/ Bluetooth module
○ WLAN card/adapter
○ Replaceable module
○ Antenna placement
Cellular card
○ Also known as a WWAN card/ adapter
○ Replaceable
○ Carrier-specific
Video card
○ Commonly integrated
■ Non-FRU (non-field replaceable unit)
Mini PCIe
○ Small form factor than PCIe
○ Successor to mini-PCI
○ 52 pin edge connector
○ M.2 is a mini-PCI express variant
○ Examples:
■ Graphics adapter
■ Wireless adapter
Screen
○ LCD
○ LED
○ OLED
○ Touchscreen
■ Resistive - several thin layers, top layers bend to touch lower
■ Capacity - less force to register touch
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Inverter
■ Takes DC and inverts it to AC
Wireless Antenna
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DC jack
○ Integrated
■ Non-FRU
○ Non-integrated
■ FRU
Battery
○ Rechargeable
○ 2-6 battery life is common
○ Replaceable
○ Vendor and model specific
■ Come in many shapes and sizes
Touchpad
○ Perform basic mouse function
Plastics/frame
○ Houses the components
○ Proprietary (non-standardization)
Speaker
○ Internal audio output device
○ Non-integrated
■ FRU
System Board
○ Proprietary (non-standardization)
○ FRU
○ Reduced power consumption
○ Throttling
○ Integrated components
CPU
○ Integrated vs non-integrated
○ Specialized cooling systems
○ Throttling technologies
■ Intel - Speed step series
■ AM- PowerNow!
Troubleshooting Laptops
➢ No display -–This is most often caused when the display is dimmed via the controls or when the display has
been sent to the external device. Try changing the screen dimness, or use the appropriate function key to cycle
through the different display options. If neither of these solutions fixes the problem, you could have a failed
backlight or inverter, which are both internal components that will need to be replaced to troubleshoot the
problem. For an iPhone or iPad that has dimmed or turned black, you should press and hold down the
Sleep/Wake button and the Home button simultaneously for at least 10 seconds. This should soon display the
Apple logo on the black background. For Android tablets and smartphones, you must take off the back cover,
reseat your battery, and then charge your phone for a few hours. However, just like the blue screen of death on
PC-based devices, Android can have the same issue. If this is the case, you will have to remove the SIM card
and battery and leave them out for 5–10 seconds. At this point, you need to charge the battery, as well. Finally,
sometimes you may have to perform a hardware factory reset. This process will permanently remove the
customer's data from the device. Make sure to back up all personal data to a computer or to the cloud. To
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perform a hardware factory reset, you would press and hold the Volume Up, Power, and Home keys
simultaneously and select Factory reset/wipe data using the volume keys. Then you would press the Power
key to start the hardware factory reset.
Dim display – This is most often caused when the display is dimmed. Change the screen dimness to see if this
fixes the problem. Also, you may need to check the switch on the laptop that tells the system that the lid is
closed. If neither of these solutions resolves the problem, either the backlight or inverter could be the cause.
Replace each of these components to troubleshoot the issue. Smartphones and tablets have dim screen
controls in the Settings menu. On an iPhone, you can swipe up the Control Center and change the display.
Android devices have apps you can download for free, such as Screen Dimmer. The dimmer feature is a great
way to change the brightness of your screen and save your battery.
Flickering display – This is usually caused by an incorrect video driver or low screen refresh rate. Update the
driver first. If this does not resolve the problem, consult the display device manufacturer's documentation for
the appropriate refresh rate. Finally, flickering can be caused by loose or bad connections. Check the internal
connections for the display if none of the other solutions works.
Sticking keys – Dust accumulation can cause keys to stick. In addition, most keys have a spring that can wear
out. First, you should try to blow out the keyboard using compressed air. It may also be necessary to clean the
individual keys. In some laptops, keys can be detached for individual cleaning. Be careful when detaching
individual keys because this can damage keyboard components. If this does not fix the problem, replace the
integrated keyboard or purchase an external keyboard. Spilled liquids are most often the cause of sticking
keys.
Intermittent wireless – This is usually caused by radio frequency interference (RFI). Research the wireless
network environment. Try to minimize the obstructions between the laptop and the wireless access point. For
example, microwaves and cordless phones can interrupt the flow or signal and cause disturbances to your
flow and connection, so do not place routers near those types of electronics. Also, research the particular
frequency in use on your wireless network to discover if you have deployed any devices that could be causing
the problem. You may need to increase the signal strength on the wireless access point. Finally, the problem
could be with the internal wireless card. Check the internal cable connections for the wireless card if none of
the other troubleshooting techniques has solved the problem.
Battery not charging – If the battery will no longer charge properly, you should totally drain the battery's
power to eliminate the memory effect. If this does not solve the problem, replace the battery with a new one.
However, the A+ number one rule is to always check the connection, so make sure that your plug snuggly fits
on the charging device. Loose or disconnected cables can be frustrating, so do not eliminate that step when
troubleshooting.
Ghost cursor/pointer drift – This usually occurs when the trackpad is too sensitive. You can change the
sensitivity settings to see if this fixes the problem. If the problem still exists, you should try installing the latest
driver for the touchpad. Finally, you could disable the touchpad and connect an external mouse. You can also
search Google for the Phantom Cursor to troubleshoot various devices.
No power – This is usually caused when you are no longer connected to an external power source and the
battery has been depleted. Make sure that the laptop is plugged into a functional external power source. Plug
the laptop into a power source and allow the battery to recharge. You may also want to reconfigure the power
settings to ensure that certain devices are not enabled when you are working using a battery.
Num Lock indicator lights – To enable or disable the number lock function, you may need to press a single
Num Lock key or use a function key combination. Read the laptop vendor's documentation to learn the
appropriate way to enable and disable the number lock function. If the number lock function is disabled, you
will notice that the cursor moves around when you use the number keys instead of numbers being entered on
the screen. If your keyboard has calculator type keys built in, you will need to enable Num Lock to use the
calculator as desired.
No wireless connectivity – This is usually caused when the wireless device has been disabled. Read the laptop
vendor's documentation to learn the appropriate function key combination that can be used to enable/disable
wireless. The device can also be disabled in Device Manager. If neither of these solutions fixes the problem,
you should check the wireless card to make sure that it is seated properly and attached to the antenna.
Replacing the wireless card or antenna may be necessary. For most mobile devices, you simply need to make
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sure that Wi-Fi is enabled or turned on. You also may need to make sure that Airplane Mode is turned off.
Airplane Mode disables several features, including WiFi.
No Bluetooth connectivity – This is usually caused when Bluetooth has been disabled. Read the laptop
vendor's documentation to learn the appropriate function key combination that can be used to enable/disable
Bluetooth. If this does not fix the problem, you should check the wireless card to make sure that it is seated
properly and attached to the antenna. Replacing the wireless card or antenna may be necessary. For mobile
devices, you probably only need to make sure that Bluetooth is enabled. As with Wi-Fi, Airplane Mode disables
Bluetooth on most devices.
Cannot display to external monitor – This is most often caused when the display has been sent to the internal.
Use the appropriate function key to cycle through the different display options. If this does not fix the
problem, you should check the cabling to the external monitor. For some displays, you will also need to make
sure that that display device itself is set to the appropriate source.
Touch Screen unresponsive – This is most often caused by a dirty screen. First, remove any screen protectors
and try to clean the touchscreen. If that does not work, reboot the device. If the problem persists, the screen
may need to be repaired or replaced. Keeping your screens clean, dust-free, and protected will extend the life
of your tablet or laptop screen. Remember that they are very fragile, so you should handle them with care.
Apps not loading – First, you should make sure that your app and the device operating system is updated.
Next, ensure that your firewall isn't configured to block the app. You could then synchronize the license for the
app. As a last resort, try removing and reinstalling the app.
Slow performance – This is usually caused by too many apps running in the background. Stop any unneeded
apps from running. If this does not resolve your issue, reboot the device. Finally, it could be that the drive in
your device is reaching its storage capacity. If that is the case, you will need to remove some data and/or apps
and possibly back up unused files to an external backup device, like a server or an external hard drive.
Unable to decrypt email – This is usually caused by a missing or expired key or certificate. Make sure the
appropriate key or certificate is installed. It may be necessary to restore them from backup. It also could be
that the device is configured to not allow encrypted email. If this is the case, then you need to enable
encrypted email.
Extremely short battery life – Always try completely draining and recharging the battery first. If the battery
continues to only have a short life, you need to replace the battery. For mobile devices, you may try changing
battery settings through the Control Panel or Settings.
Overheating – If your mobile device overheats, try removing the protective case that you have it in. Other
solutions are to remove the device from direct sunlight, shut down apps you are not using, or buy a glare
screen and turn down the brightness. Finally, turn your mobile device off or put it in Airplane Mode when not
in use.
Frozen system – First, try plugging the mobile device into a power supply. Then you should try to power down
or restart the device the normal way. If that is not possible, then remove the battery for a few seconds. Next,
you should delete the app that is causing the device to freeze. As a last resort, reset the device to the factory
defaults. For an Apple mobile device, another possible solution is to restore the device using iTunes. You can
also consult the manufacturer's website or device documentation on how to reset the device.
No sound from speakers – This is most often caused by the sound being muted or the device being in silent or
vibrate mode. If that does not fix the problem, try adjusting the volume. As a last resort, reboot the device. If
you are using Bluetooth speakers, remove the device through Settings, re-add the speakers, and resync.
GPS not functioning – First, you should ensure that the GPS function is enabled. If that is not the problem,
reboot the device. Then try turning location services off and then back on. Finally, you could perform a GPS
reset.
Swollen battery – Swollen batteries are an explosion or leaking hazard and should be replaced immediately.
Swollen batteries are usually found in devices like laptops and mobile devices that use lithium batteries.
Batteries can become swollen due to manufacturing defects or by not using the right charger. Lithium-ion
batteries do not like to be overcharged because there is no place for the gasses in the overheated cells to go.
The overheated batteries expand, swell, and appear warped. Always replace swollen batteries.
Mobile Devices
➢ Tablets
○ Proprietary designs
○ Touchscreen displays
○ Operating systems
■ iOS
■ Android
■ Windows 10
○ Features
■ Embedded RAM
■ SSD (NVRAM)
■ Cameras
■ Audio ports
■ Charging ports
■ Power button
■ Screen orientation button
➢ Smartphones
○ Proprietary designs
○ Small computers
○ Touchscreen displays
○ Operating systems
■ Android
■ iOS
○ Features
■ Cameras
■ Power button
■ Charging port and wireless charging
■ Volume button
■ Audio port
➢ GPS
○ 31 satellites (27 operational, 6 stand-by)
○ Arranged in a constellation
➢ Wired Devices
○ USB
■ Mini-USB
■ Micro-USB
■ USB-C
○ Lightning
■ iOS
○ Proprietary vendor-specific port
■ Microsoft surface tablet charger
■ ASUS Tablet
➢ Wireless
○ NFC (Near field communication)
○ Bluetooth
○ Infrared (IR)
➢ Tethering vs Hotspot
○ Tethering
■ Wired connection
■ Connect a single device
■ Internet access
○
■ Greater security
Hotspot
■ Wireless connection
■ Creates a small wireless network
■ Connect multiple devices
■ Internet access
■ Less security
Mobile Connectivity and App Support
➢ http://www.differencebetween.net/technology/difference-between-tethering-and-hotspot/
➢ https://www.soundguys.com/how-to-use-bluetooth-12881
➢ Gmail Support
○ https://support.google.com/mail/answer/7126229?hl=en
➢ iOS mail
○ https://support.apple.com/en-us/HT202304
➢ S/MIME
○ https://www.globalsign.com/en/blog/what-is-s-mime/
➢ Exchange for Android
○ https://support.office.com/en-us/article/set-up-email-in-the-outlook-for-android-app-886db551-8dfa4fd5-b835-f8e532091872
➢ Wireless and Cellular
○ Hotspot
○ Tethering
○ Airplane mode
➢ Bluetooth
○ Enable bluetooth on host device
○ Enable pairing
○ Find device for pairing
○ Enter pin code
○ Test connectivity
➢ Corporate and ISP email configuration
○ IMAP - Connect to email server and manage email. Port 143
○ POP3 - Retrieve email off a server. Port 110
○ S/MIME
■ Keeping emails secure
○ SSL/TLS
■ Secure websites
➢ Integrated commercial provider email configuration
○ iCloud
○ Google
○ Exchange Online
○ Yahoo mail
➢ PRI (Product Release Information)
○ Radio Settings
○ Provider network information
○ Identifiers
➢ PRL (Preferred Roaming List)
○ Built by providers
○ Database allowing for roaming
➢ IMEI (International Mobile Equipment Identity)
○ Uniquely identifies phones
○ Validates a device
○ Can be used to blacklist stolen phones
○ 15-digit number
○ 16-digit number (newer)
➢ IMSI (International Mobile Subscriber Identifier)
○ Uniquely identifies every used of a cellular field
○ 64-bit field
Mobile Synchronization
➢ Exchange on iOS
➢ https://support.apple.com/en-us/HT201729
➢ Syncing iPhone, iPad using Mac or PC
○ https://support.apple.com/en-us/HT201253
➢ Syncing on Android
○ https://support.google.com/android/answer/9453724?hl=en
○ https://www.google.com/sync/index.html
➢ We synchronize to keep mobile devices data up to date with data on our computers
➢ Keeps data consistent across multiple mobile devices
➢ Common data synchronization
○ Contacts
○ Applications
○ Email
○ Pictures
○ Music
○ Videos
○ Calendar
○ Bookmarks
○ Documents
○ Location data
○ Social media data
○ E-books
○ Passwords
➢ Common connection types
○ USB
○ WiFi
○ Bluetooth
○ NFC
➢ SSO
○ Single sign-on
○ Enter single set of credentials
○ Reduces how often you enter credentials
○ Used for Active Directory Domain, Facebook, Google, Microsoft
Printers
➢ Types:
○ Inkjet printers
○ Thermal printers
○ Impact printers
Laser printers
3D printers
MFD printers
Virtual printers
■ Print to file
■ Print to PDF
■ Print to XPS
■ Print to image
Home Printers
Point-of-sales printers
Business printers
Industrial printers
Inkjet printers
○ Sprays ink onto the media
○ Most common
○ Also known as a page printer
○ Components:
■ Ink cartridge
■ Print head
■ Roller
■ Feeder
■ Carriage (where cartridge goes)
■ Belts
○ The nozzle gate controls the flow of ink from the ink cartridge to the paper. When an inkjet printer
starts printing, the nozzle gate opens and allows the nozzle to spray the ink onto the paper. After
printing is stopped, the nozzle gate shuts down to stop the flow of the ink. When the printer is idle, the
nozzle gate remains closed to prevent the flow of the ink from the ink cartridge
Thermal Printers
○ Use heating element to produce graphical output
○ Types:
■ Direct thermal
■ Thermal wax transfer
■ Dye sublimation
○ Components
■ Feed assembly
■ Heating element
■ Thermal printer paper
Impact Printer
○ Striking element and ink ribbon produced graphical output
○ Good at multi layer printing
○ Types:
■ Daisy wheel
■ Dot-matrix
■ Line (fastest)
○ Components:
■ Print head
■ Ink ribbon
■ Tractor feed
■ Impact paper
Laser Printers
○ Produces graphical output through light and electrical current
○ Also a page printer
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Components:
■ Imaging drum and toner cartridge
■ HVPS (high voltage power source)
■ Laser scanning assembly
■ Primary corona - puts a uniform negative charge (-400V) on the photosensitive drum
■ Transfer corona - Puts a positive static charge on the paper as it rolls in
■ Transfer roller
■ Transfer belt
■ Pickup rollers
■ Separator pads
■ Fuser assembly
○ Laser printer toner cartridges ordinarily contain a photosensitive drum and electrostatically charged
toner, which is fused to paper during the printing process. To reduce maintenance costs, printer
manufacturers typically incorporate laser printer components into replaceable toner cartridges
○ A laser printer's photosensitive drum has a cylindrical surface that laser light strikes. The light writes a
path on the drum and leaves an electrical charge wherever it strikes the drum, eventually placing the
image of an entire page on the drum. After a page of the document is completely replicated by the
electric charge on the drum, the drum is rolled in toner, which is powdery ink consisting of plastic
particles bonded to iron particles. The iron particles in the toner are sensitive to the electric charge,
and therefore, adhere to the charged image of the document on the drum
○ The printer's fuser contains two rollers, which use heat and pressure at this point in the process to fuse
the image onto the paper. After the document is printed, the electrical charge is removed from the
drum and the excess toner is collected for reuse. A fuser can also be referred to as a fuser assembly
○ The transfer corona applies an electric charge to printer paper with a polarity opposite to that of the
toner particles to generate electrostatic attraction between the paper and the ink. Attractive
electrostatic force then causes the toner to move from the drum to the paper. At this point, the toner is
resting on the paper but still needs to be attached to the paper to create a permanent image
○ Laser printer toner cartridges should only be purchased from the laser printer manufacturer to ensure
highest quality printing and protect against printer malfunction. Recycled cartridges should be
avoided. In addition, you should never attempt to refill a laser printer toner cartridge
○ The formatter board, also known as the formatter card, control board, or system board, contains all
the circuitry required to operate the printer and control its many components. It receives control
signals from the computer and formats the data to be printed. The formatter board or system board
also monitors the conditions within the printer and responds to input from its various sensors.
➢ 3D Printers
○ Computer controls printer to create 3D object
○ Components:
■ Controller board
■ Filament
■ Frame
■ Stepper motor and belts
■ Print Head (extruders)
■ Print Bed
■ Print Surface (allows you to remove 3D object)
➢ MFDs
○ Multi function Device
○ All-in-one
○ Functions:
■ Printing
■ Copying
■ Scanning
■ Fax
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➢ Duplexing Assembly
○ Duplexing paper feed
○ Allows for two-sided printing
○ Passes the paper through twice
➢ Virtual Printers
○ Converts documents to a specified format
○ Not physical printers
○ Print to file
○ Print to PDF
○ Print to XPS
○ Print to image
Printer Processes and Maintenance
➢ Inkjet print
○ http://www.image-specialists.com/ink_int_injet_printer.aspx
○ https://www.custompartnet.com/wu/ink-jet-printing
○ http://facweb.cs.depaul.edu/sgrais/how_inkjet_printers_work.htm
○ https://www.explainthatstuff.com/inkjetprinters.html
➢ Inkjet Maintenance
○ https://www.internet-ink.com/blog/Printers/2015/04/10-Printer-Care-8-Ways-to-Care-For-Your-InkjetPrinter
➢ Thermal Wax Transfer Print
○ https://www.webopedia.com/TERM/T/thermal_printer.html
○ https://www.pcmag.com/encyclopedia/term/thermal-wax-transfer-printer
➢ Direct Thermal Printer
○ https://www.zebra.com/us/en/resource-library/faq/printing/difference-between-direct-thermal-and-t
hermal-transfer-printing.html
○ https://www.labelvalue.com/blog/labels/what-is-direct-thermal-printing.html
➢ Dye Sublimation Printer
○ https://magicard.com/knowledge-centre/what-is-dye-sublimation-printing/
➢ Thermal printer maintenance
○ https://www.blancolabels.com/blog/thermal-printer-printhead-maintenance-tips/
○ https://www.labelsontime.com/maintenance-for-a-thermal-printer
➢ Dot Matrix Printers
○ https://smallbusiness.chron.com/dot-matrix-printer-work-56581.html
○ How does a dot matrix printer work? - Printerbase News Blog
➢ Dot Matrix Printer Maintenance
○ https://www.fixmyprinters.com/7-rules-keep-dot-matrix-printer-best-condition/
➢ Laser Printer Print Process
○ Laser printing - Wikipedia
○ The Laser Printing Process: How Does It Work? - Bright Hub
○ https://www.howtobuildtheperfectprinter.com/laser-printer-working-process/
➢ Laser Printer Maintenance
○ Laser Printer Cleaning and Maintenance Tips#2 – TonerParts
○ One Computer Guy Acquires pctechbytes.com
○ Printer Maintenance Plan for Laser Printers: 5 Important Tips to Follow - Ink Toner Store Blog
➢ Inkjet Print Process
○ Preparation
○ Ink Dispersion
Inkjet printers use either of two methods to push ink onto the print medium, typically paper.
One method is to precisely vibrate a piezoelectric crystal, which then pumps ink through a
nozzle. The other method is to apply a voltage to a resistor, which heats ink to the boiling
point. When the ink boils, the vaporization pressure pushes the ink through fixed-position
nozzles and onto paper. The first method is referred to as mechanical vibration, and the
second method is referred to as thermal shock.
○ Ink deposit
■ Print head assembly does not touch paper
○ Paper advance
○ Maintenance
■ Clean heads
■ Replace cartridges
■ Calibrate
■ Clear jams
➢ Thermal Printer Process
○ Direct Thermal
○ Thermal Wax transfer- uses solid wax sticks with melts
○ Dye sublimation - use heat to change solid to almost gas
○ Maintenance
■ Replace paper
■ Clean heating element
➢ Impact Printer Process
○ Dot-matrix uses a pin that strike a ribbon
○ 24-pin variety produce NLQ
○ Line type can produce 3000 lines
○ Maintenance
■ Replace ribbon
■ Replace print head
■ Replace paper
○ A defective print head can cause a dot matrix printer to print only partial characters, and serious
defects can prevent printing completely. Dot matrix printers use an array of pins to strike an inked
printer ribbon that generates images on paper. The individual pins in the print head are controlled by
electromagnets, which move the pins to form specific characters
○ The failure of some or all of the pins in the print head to move in response to the electromagnetic force
will have an obvious and immediate effect on a printer's ability to print specific characters. However, a
print head could also be misaligned in such a way that only the bottom half of its pins strike the printer
ribbon. In such cases, the printer would render only partial characters, even if all components in the
print head are functioning correctly
➢ Laser Printer Process
○ Processing – The computer sends the printed document to the printer spooler. The printer spooler
contacts the printer. The printer processes the image.
○ Charging – The charge corona (also referred to as the primary corona) applies a uniform charge
(typically negative) to the imaging drum. This creates a "blank slate" to which the laser will write.
○ Exposing – The modulated laser beam writes an electrostatic image on the rotating drum. Any areas on
the imaging drum that the laser beam touches lose most of their electrostatic charge. This differential
in electrostatic charge between the areas of the drum that have been written to and the remainder of
the drum allows the image to attract toner in the next phase.
○ Developing – Toner is transferred from the toner cartridge to the imaging drum. The toner cartridge
has a metallic roller called a developing cylinder that takes on a charge equal to the imaging drum.
The toner sticks to the developing cylinder, and as it rotates toward the paper, a "toner fog" is created
as the toner is both attracted to and repelled from the imaging drum. The toner is repelled from areas
that were not touched by the laser because they have the same electrostatic charge as the toner, and it
■
is attracted to the areas on the drum that were touched by the laser because of the difference in the
electrostatic charges. This creates an image that is ready to be transferred to a piece of paper.
○ Transferring – The transfer corona charges the paper so that the toner on the imaging drum is
attracted to the paper as the drum rotates and the paper and drum come into very close proximity. A
corona discharges the electrostatic charge on the paper immediately after the toner transfers from the
imaging drum to the paper, preventing the paper from sticking to the drum. Transfer rollers move the
paper through the transferring process.
○ Fusing – The final step permanently bonds the toner to the paper. A fusing roller, heated by a quartz
lamp, melts the toner to the paper, and the paper exits the printer.
○ Cleaning – A rubber cleaning blade removes any toner left on the imaging drum and deposits it into a
waste bin, and a discharge lamp neutralizes the charge on the drum.
○ Please Cows Won't Do The Fandango Cordially
○ Maintenance
■ Replace toner
■ Apply a maintenance kit
■ Calibrate
■ Clean
➢ 3D Printer Process
○ Creates objects by joining materials in multiple layers
○ Computer controlled
Printer Troubleshooting
➢ Inkjet
○ https://www.techrepublic.com/article/troubleshooting-common-inkjet-printer-problems
○ https://www.pcworld.com/article/181912/article.html
○ https://webpage.pace.edu/ms16182p/troubleshooting/inkjet.html
➢ Thermal
○ https://jet-marking.com/common-thermal-printer-problems/
○ http://printers.iyogi.com/help-support/troubleshooting/thermal-printer-troubleshooting.html
○ https://www.satoamerica.com/support/tech-tips/understanding-thermal-print-head-life
➢ Laser Printer
○ https://cash4toners.com/info/2018/10/16/7-common-laser-printer-problems/
○ http://www.lbrty.com/tech/articles/general/print_quality/ta_printquality.html
○ https://webpage.pace.edu/ms16182p/troubleshooting/laser.html
➢ Dot Matrix
○ https://panasonic.net/cns/pcc/support/printer/trouble_shooting/dmptrouble.html
○ https://compuprintplus.com/diagnosing-fixing-common-dot-matrix-printer-problems/
○ https://ranksheet.com/Solutions/kb-Windows-Vista/511_Troubleshooting-Dot-Matrix-Printer.aspx
➢ Streaks – This problem is usually caused by a malfunctioning fuser because the fuser is responsible for fusing
the toner to the paper. Replace the fuser. In inkjet printers, this could be caused by a malfunctioning ink
cartridge or dirty print head. Replace the cartridge, or clean the print head. In dot matrix printers, this is
caused by a dirty print head. Clean the print head
➢ Faded print – This is usually caused when a toner cartridge, ink cartridge, or ribbon is close to empty. You
should replace the cartridge or ribbon with a new unit
➢ Ghost images – Ghost images are light images of pages that were previously printed that are appearing on the
currently printed page. This is usually caused by the erasure lamp or cleaning blade. The cleaning blade is part
of the toner cartridge and is easier to replace than the erasure lamp. Try replacing it first. If it does not fix the
problem, you will need to replace the erasure lamp
➢ Toner not fused to the paper – This problem is usually caused by a malfunctioning fuser. Replace the fuser.
➢ Creased paper – This is usually caused by a paper jam. Check the printer internally to ensure that no paper
jams or small scraps of paper are obscuring the paper path. Creased paper can also be caused by worn pickup
rollers. Replace the pickup rollers. Pickup rollers are part of printer maintenance kits
➢ Paper not feeding – This is usually caused by worn pickup rollers. Replace the pickup rollers. Pickup rollers are
part of printer maintenance kits
➢ Paper jam – When a paper jam occurs, you need to first completely clear the paper jam. If the paper jam
continues to be a problem, you need to determine which printer part could be causing the paper jams. Check
to make sure that you are using paper that is approved for the printer. Paper that is too thick will cause paper
jams. Also, high humidity can cause the paper to stick together, which causes paper jams. Paper jams can also
be caused by worn rollers or broken drive gears. Rollers are part of the printer's maintenance kit. If you suspect
broken drive gears, you will need to contact a printer technician to replace the drive gear. If the paper jams
after reaching the corona assembly, the problem could be caused by the static eliminator strip, which needs to
be replaced by a printer technician
➢ No connectivity – If this problem is with a locally attached printer, make sure that the cable is properly
attached. Try replacing the cable with a new cable. If this problem is with a network printer, ping the printer to
see if it is available. If you can ping the printer, you probably have an incorrect setting or driver
➢ Garbled characters on paper – This problem is usually caused by an incorrect printer driver. Install the most
up-to-date version of the correct printer driver
➢ Vertical black lines on page – Vertical black lines are caused by scratches on the drum or dirty corona wire. If
you suspect that scratches are on the drum, replace the toner cartridge. If you suspect the corona wire, try
cleaning it first. If the problem still persists, replace the toner cartridge. For inkjet printers, you should try
cleaning the print head or replacing the ink cartridge
➢ Vertical white lines – Vertical white lines are caused by a dirty transfer corona wire. Clean the corona wires. The
corona wire is part of the toner cartridge and can be cleaned using a brush. For inkjet printers, clean the print
head. If these solutions do not work, you will need to replace the toner cartridge or ink cartridge
➢ Backed up print queue – You can try to delete the print job from the print queue that you suspect is causing
the problem. If this does not fix the problem, you will need to stop and restart the print queue. This will result
in all jobs in the print queue being deleted. All users will have to resubmit their print jobs
➢ Low memory errors – Often just turning the printer off and back on will fix this problem. If the problem
persists, you could print the page at a lower resolution or change the print page so that it is less complex. If
this does not fix the problem, you may try installing a different driver for the printer. You could also add more
memory to the printer
➢ Access denied – This is most often caused by the access control list (ACL) for the printer. Make sure that the
user has been granted print permission. This can also be affected by print availability and print priority. Print
availability is a way to set up a printer so that a particular group can print to the printer during certain times. If
a user attempts to print to the printer outside of the availability times, the print job is unsuccessful. Print
priority allows you to assign jobs from a particular group a higher priority. If this technique is used, jobs that
have a higher priority will take precedence over other print jobs. Print availability and print priority can
prevent or delay print jobs
➢ Printer will not print – If you are sure that the printer has power and paper, you should try printing a test page.
If the test page is unsuccessful, you probably have a connection issue. Replace the cabling if it is a local printer.
If it is a network printer, complete network troubleshooting techniques to troubleshoot the issue.
➢ Color prints in wrong print color – This is usually the result of a dirty print head. Clean the print head first. If
the problem persists, replace the toner cartridge or ink cartridge. Calibrating the cartridge may also help
➢ Unable to install printer – If this problem occurs, the account used to install the printer probably does not have
permissions to install the printer. Use an administrative-level account to install the printer
➢ Error codes – For any error codes you are given, consult the manufacturer's documentation or website to get
details on the error. Follow the manufacturer's suggested troubleshooting steps for the particular error you
receive.
➢ Printing blank pages – The most often cause of this problem is that the printer is out of ink or toner. It can also
be caused by clogged print nozzles in an inkjet printer. For a laser printer, the toner cartridge has sealant tape
over the toner dispenser. If this tape is not removed, pages will be blank.
➢ No image on printer display – This is most often caused because the printer is unplugged or in standby mode
Virtualization
Basics
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https://www.tutorialspoint.com/virtualization2.0/virtualization2.0_overview.htm
https://www.bmc.com/blogs/it-virtualization/
https://www.vmware.com/solutions/virtualization.html
Virtualization allows multiple OS to run on one system
Allows creation of virtual machine (VM)
○ Also known as guest machine
○ Created within a single computing environment
Host machine is the physical computer that the virtualized environment will be created on
○ Typically workstations or servers
Virtualization allows greater efficiency using hardware resources
○ Run software built for different platforms
○ Isolated computing environments
○ Can reduced amount of physical computers
Server-side virtualization
○ All guest machines are created within a server computing environment
○ Used is enterprises and cloud computing
○ Scalable
Client-side virtualization
○ All guest machines are created within a thick client computing environment
○ Great for testing
○ Not scalable
Hypervisors
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https://www.vmware.com/topics/glossary/content/hypervisor
https://www.ibm.com/cloud/learn/hypervisors
https://www.howtogeek.com/66734/htg-explains-what-is-a-hypervisor/
https://www.networkworld.com/article/3243262/what-is-a-hypervisor.html
Hypervisor is the process that allows for the creation of virtual machines
Runs the virtual machines
Allows a host computer to support multiple operating systems
Manages distribution of host resources to the virtual machine
Hypervisor Types:
○ Type 1 - Bare metal hypervisor, sits right on top of hardware
■ Greater performance level
■ Server-side virtualization
■ Mcirosoft Hyper-V
■ VMware ESXi
■ Citrix
○ Type 2 - Host-based hypervisor. sits on top of the host operating system
■ Lower performance
■ Not scalable
■ Client-side virtualization
■ Testing
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VMWare Fusion and workstations
Oracle VirtualBox
Requirements for Virtualization
➢ Host machine
➢ Virtual machine
○ VM set to internal network can communicate with other VMs and the host but not the internet
○ VM set to external network can communicate with other VMs, the host, and the internet
○ VM set to Private network can only communicate with other VMS not the host or internet
○ VM set to Local Host can only communicate with itself
➢ Physical resources
○ CPU - needs to support virtualization and enabled in UEFI/BIOS
○ RAM
○ Storage
○ Networking
➢ Network requirements
○ Virtual NIC
○ Virtual switch (allow communication)
■ VM-to-VM
■ VM-to-Host
■ VM-to-LAN
➢ Security requirements
○ Host security
○ Guest security
➢ Emulator requirements
○ A program that lets you run software from a completely different device on your computer
○ Different than hypervisor
○ Mimics the physical hardware that the software ran on, for example, ARM emulator allows use of
android apps
Cloud Computing
Models of Cloud
https://www.givainc.com/blog/index.cfm/2015/8/3/Three-Main-Categories-of-Cloud-Computing
https://www.paranet.com/blog/bid/128267/the-three-types-of-cloud-computing-service-models
https://www.ssh.com/cloud/computing/models
http://www.itmanagerdaily.com/3-cloud-computing-models-explained/
https://www.webopedia.com/TERM/C/cloud_computing.html
Cloud computing
○ Delivery of computing system over the internet
➢ Common Cloud Models
○ SaaS - Software as a Service
■ Google cloud, office 365
■ Applications run remotely and accessed via a web browser
■ Vendor Responsibilities:
● App maintenance
● App data
● Operating system
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● Virtualization infrastructure
● Hardware infrastructure
● Network infrastructure
■ Customer Responsibilities:
● Payment of services used
○ PaaS - Platform as a service
■ Provides customers with a development environment
■ Vendor responsibilities:
● Operating system
● Runtime environment
● Virtualization infrastructure
● Hardware infrastructure
● Network infrastructure
■ Customer responsibilities:
● App maintenance
● App data
○ Iaas - Infrastructure as a service
■ Provides the customer computing infrastructure
■ Virtual machines such as AWS
■ Vendor Responsibilities
● Virtualization infrastructure
● Hardware infrastructure
● Network infrastructure
■ Customer Responsibilities:
● App maintenance
● App data
● Operating systems
➢ Common cloud architectures
○ Public Cloud (AWS, Google, Azure)
■ Available to anyone
○ Private Cloud
■ Company owns the data center and the cloud resource
■ Expensive
■ Complete control of information
○ Hybrid Cloud
■ Provides private and public cloud
■ Most common
■ On premise cloud and external cloud
○ Community Cloud
■ Big company cloud that can be separated between different groups of people
■ Sales, Marketing, HR
■ Cloud within a Cloud
Features of Cloud
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https://www.controleng.com/articles/five-characteristics-of-cloud-computing/
https://searchcloudcomputing.techtarget.com/feature/7-key-characteristics-of-cloud-computing
https://thinkitsolutions.com/characteristics-of-cloud-computing/
http://comp1220uwikatrina.weebly.com/
Shared resources
○ Internal resources
■ On-premise
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■ Store locally
○ External resources
■ Cloud storage
■ Storage on the providers network
■ Cloud providers manage it
Rapid Elasticity
○ Cloud is easy to scale up and scale down very quickly this is called rapid elasticity
On-demand
○ Resources are available when you need it, they are available on-demand
Resource pooling
○ Taking all the infrastructure and leasing it to customers
Measured service
○ On pay for what you use
○ Occurs by using a meter (metering)
Off-site email applications
○ Gmail, outlook
○ Store emails in cloud
Cloud file storage services
○ OneDrive
○ Icloud
○ Google Drive
Synchronization apps
○ OneDrive
○ iCloud
○ Allows all apps to synchronize between multiple devices
Virtual application streaming/ cloud-based application
○ Apps for cellphones/tablets
○ Apps for laptops/desktops
Virtual Desktop
○ Cloud-based virtual desktop infrastructure
○ Web browsers can connect to the OS
○ Centralized virtual desktop infrastructure
○ Great for thin-client
Networking
Ports and Protocols
➢ TCP
○ Connection Oriented
○ Guaranteed delivery
○ Slower
➢ UDP
○ Connection-less (best effort)
○ Not guaranteed delivery
○ Faster
➢ HTTP traffic is sent over port 80 when browsing websites
○ Port is a logical end-point of a connection
➢ HTTPS traffic is sent over 443 for secure browsing
➢ FTP (file transfer protocol) is sent over port 21 to transfer files
➢ SMB/CIFS is sent over port 445 and ports 137-139
➢ AFP (apple filing protocol) is sent over port 548
➢ SMTP (simple mail transfer protocol) is sent over port 25
○ Sends emails
➢ POP3 is sent over port 110
○ Retrieves emails
➢ IMAP (internet mail access protocol) is sent over port 143
○ Sends and retrieves emails
○ Manage email in server
➢ DNS (Domain Name Service) is sent over port 53
○ Name resolution
➢ DHCP is sent over port 67 and 68
➢ Telnet is sent port 23
○ Clear text protocol
○ Not secure
➢ SSH is sent over port 22
○ Secure version of telnet
➢ SNMP AGENT is sent over port 161, SNMP TRAP sent over port 162
○ Track health of devices within network
➢ SLP (service location protocol) is sent over port 427
○ Locate services within a network
➢ LDAP is sent over port 389
○ Lightweight directory access protocol
○ Search directories within network
➢ RDP (remote desktop protocol) is sent over port 3389
○ Control another windows machine or server
➢ NetBIOS
○ Legacy
○ Windows networks
○ Application communication
○ Broadcast communications
○ Name resolution
○ Local area networks
○ Not routable
➢ NetBT
○ NetBIOSs over tcp/ip
○ Windows networks
○ Routable
○ Maps netBIOS names to IP addresses
➢ NetBIOS Name Service
○ Port 137
➢ NetBIOS Datagram Service
○ Port 138
➢ NetBIOS Session Services
○ Port 139
Devices
➢ Routers
○ Connect multiple networks together
○ Make decisions based on IP addresses
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○ WAN
○ Devices don't have to be directly connected
Switches
○ Allows for local communication
○ Limited to LAN
○ Devices have to be directly connected
○ Makes decisions based on MAC addresses
Access Points
○ Allows wireless devices to connect to the network
Hub
○ Not used as much
○ Dumb device
○ Just repeats data to every device connected
○ Multi-port repeater
Repeaters
○ Regenerate signal
Bridge
○ Makes decisions based on MAC address
○ Blocks communication if it is not needed
○ Similar to a switch but not as smart
Cloud-based network controller
○ Virtualized
Firewalls
○ Control network communication based on a set of rules
○ Security mechanism
○ Types:
■ Host-based - Screen traffic only a single computer not the entire network
■ Network-based - Screens all traffic coming into and out of the local network
IDS and IPS
○ Detect signs of intrusion
○ Alert administrator
○ Log information
○ IPS also implements counter measures, IDS just detects.
Cable/DSL modem
○ Connects home devices to the internet
Power over Ethernet (PoE)
○ Switch PoE
○ Injectors PoE
■ Injects power into communication channel or switch
Ethernet over power
○ Get ethernet from a power outlet
○ Power sourcing equipment
○ Powered device
Patch panel
○ Connects a pair of drop cables
Wireless Standards
➢ IEEE 802.11 Standard
○ February 8th
○ Standardized WLAN technologies
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Each revision of the standard has important characteristics
■ Speed
■ Frequency
■ Distance
■ Backwards compatibility
■ Antenna Tech
802.11a
■ Speed: 54Mbps
■ Frequency: 5GHz
■ Distance: 75 ft
■ Compatibility: 802.11n,ac
802.11b
■ Speed: 11Mbps
■ Frequency: 2.4GHz
■ Distance: 100-115ft
■ Compatibility: 802.11g,n
802.11g
■ Speed: 54Mbps
■ Frequency: 2.4GHz
■ Distance: 125ft
■ Compatibility: 802.11b,n
802.11n (MIMO)
■ Speed: Up to 600Mbps
■ Frequency: 2.4 and 5 GHz
■ Distance: 300 ft+
■ Compatibility: 802.11a,b,g
802.11ac (MU-MIMO)
■ Speed: 1.3Gbps (1300 Mbps)
■ Frequency: 5GHz
■ Distance: 100-115ft
■ Compatibility: 802.11a,n
➢ 2.4 GHz
○ There are up to 14 channels. US only uses 11 channels
○ Channels 1,6,11 are non-overlapping
○ Channel overlap can cause interference and issues
○ Access point usually handles this
○ Heavily saturated
➢ 5 GHz
○ 25 non-overlapping channels
○ Less congestion
○ Greater bandwidths
■ 20 MHz
■ 40 MHz
■ 80 MHz
■ 160 MHz
➢ Bluetooth standards
○ Bluetooth 1.1
■ Speed: 768 Kbps
■ Frequency: 2.4 Ghz
■ Distance: 10 m
■ Security: Low
■ NFS Support: No
Bluetooth 2.0 + EDR (enhanced data rate)
■ Speed: 2.1 Mbps
■ Frequency: 2.4 Ghz
■ Distance: 10 m
■ Security: Improved
■ NFS Support: Yes
○ Bluetooth 2.1+ EDR
■ Speed: 3 Mbps
■ Frequency: 2.4 Ghz
■ Distance: 10 m
■ Security: Improved
■ NFS Support: Yes
○ Bluetooth 3.0+ HS (high speed)
■ Speed: 24 Mbps
■ Frequency: 2.4 Ghz
■ Distance: 10 m
■ Security: Improved
■ NFS Support: Yes
○ Bluetooth 4.0 LE (Low energy)
■ Speed: 25 Mbps
■ Frequency: 2.4 Ghz
■ Distance: 50 m
■ Security: Improved
■ NFS Support: Yes
➢ Cellular Service
○ 3GPP Standards
○ 3G
■ Upload Speed: 2 Mbps
■ Download Speed: 7.2 Mbps
○ 3G HSPA+
■ Upload Speed: 22 Mbps
■ Download Speed: 42 Mbps
○ 4G LTE
■ Upload Speed: 50 Mbps
■ Download Speed: 150 Mbps
○ 4G LTE- Advanced
■ Upload speed: 150 Mbps
■ Download speed: 300 Mbps
➢ RFID
○ Electromagnetic fields
○ Identify and track objects
○ Components
■ RFID tags
■ RFID readers
➢ ZigBee
○ Low Power
○ Low bandwidth
○ Personal area network
○ 802.15.4 (IEEE 802.15 WPAN)
○ Examples:
■ Home Automation
■ Medical devices
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➢ Z-Wave
○ Low-latency
○ Low bandwidth
○ Mesh network
○ Home automation
○ Residential appliance control
Internet Connections
➢ Cable Connection
○ https://www.reviews.org/internet-service/cable-internet-work/
○ Cable Modems use RJ6 and RJ45
➢ DSL
○ https://computer.howstuffworks.com/dsl.htm
○ https://techterms.com/definition/dsl
○ DSL modems use RJ11 and RJ45
○ Digital subscriber line
○ Digital signals
○ Transmitted over telephone lines
○ Types:
■ ADSL
● Different uploads and download speeds
● Asymmetric DSL
■ SDSL
● Symmetric DSL
● 1.5Mbps upload and download
■ VDSL
● Very High DSL
● 52Mbps up and 16Mbps down
➢ Dialup
○ https://www.webopedia.com/TERM/D/Dial_Up_Networking.html
○ https://whatismyipaddress.com/dialup
○ https://www.speedcheck.org/wiki/dial-up/
○ Modem Card that connect to Dial Up modem
○ RJ11 connectors are used 4P4C
○ Digital signals
○ Transmitted over analog lines (PSTN/POTS)
○ Used in disaster recovery
○ Low cost, low bandwidth = 56Kbps
➢ Fiber Optics
○ Optical light transmission
○ Extremely long distance
○ High bandwidth
○ Expensive
○ Multimode
■ Shortest fiber lengths
■ Multiple light sources
■ 50 or 65 micron core
■ 125 micron outer shield
○ Singlemode
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Longest fiber lengths
Single light source
10 micron core
125 micron outer shield
➢ Satellite
○ Global communications
○ Line-of-sight (LoS)
○ https://whatismyipaddress.com/wireless
○ https://broadbandmatters.com/what-are-wireless-broadband-technologies
○ Latency issues
○ Slow connections
○ Components
■ Space segment - Consists of the satellite and space around it
■ Ground Segment - Satellite sends signal down to the base station which bounces signal to
reception equipment on your home
➢ ISDN
○ https://www.rfwireless-world.com/Tutorials/ISDN-tutorial.html
○ https://www.geeksforgeeks.org/integrated-services-digital-network-isdn/
○ Integrated services digital network
○ Similar to dialup
○ Uses RJ11 jack
○ Types:
■ Basic-rate interface (BRI) - Lower bandwidth, 128 Kbps, residential/home office
■ Primary-rate interface (PRI) - Higher bandwidth, 1.544 Mbps, enterprise
➢ Cellular
○ GSM (2G
○ CDMA (2G)
○ HSPA (3G)
○ LTE (4G)
○ 2020 (5G)
➢ LoS Wireless Internet Service
○ WiMax
■ IEEE 802.16
■ WMAN network type
■ Succeeded by LTE
○ LTE
■ Long-term evolution
■ 4G technology
■ VariantsL
● LTE
● LTE-A
● LTE-A pro
Network Types
➢ LAN
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Local area network
Single geographical region
Short-range links
Single administrative body
➢ WAN
○ Wide area network
○ Connects multiple geographical regions
○ Links owned and maintained by carrier
➢ PAN
○ Personal area network
○ All the devices connected inside a home
➢ WPAN
○ Wireless personal area network
○ IEEE 802.15
○ 2-8 wireless devices
➢ MAN
○ Metropolitan area network
○ Connects multiple LANs within a city or municipality
○ Spans just a single city
➢ WMN
○ Wireless Mesh Network
○ Google home, z wave, ubiquiti networks
○ Allows for easy communication
➢ Perimeter Network
○ A perimeter network (formerly called a Demilitarized Zone or DMZ) is a portion of a private network
connected to the Internet and protected against intrusion. Certain services may need to be made
publicly accessible from the Internet (such as a web, email, or Minecraft server) and they should be
installed in the perimeter network instead of in your intranet
Network Tools
➢ Cable stripper
○ Used for copper video
○ Coaxial cables, ethernet cables
➢ Cable crimper
○ Terminate end of copper media
○ Joins cables together
➢ Cable tester
○ Verify that copper cable has functionality
➢ Multimeter
○ Test electric current
➢ Tone generator and locator (probe)
○ Identify a single cable ends with an audible sound
➢ Loopback plug
○ Allows test of network adapter
➢ Punchdown tool
○ A hand tool used to connect telecommunications and network wires to a patch panel, punch down
block, keystone module, or surface mount box
➢ Wi-fi analyzer
○ Test signal strength,identify wireless access points close by and channels
IP Addresses - IPv4
➢ https://whatismyipaddress.com/ipv4-parts
https://docs.oracle.com/cd/E19455-01/806-0916/6ja85399u/index.html
https://www.colocationamerica.com/ip-services/ipv4.htm
32- bit binary number
Represented in dotted-decimal notation
Components:
○ Network identifier
○ Host identifier
➢ Subnet mask identifies these components
➢ IP Address:
○ 192.168.1.10
○ Dotted-decimal
○ 192.168.1 - street name (network ID)
○ .10 - house number (Host ID)
➢ Converting Decimal to Binary
○ Decimal : 192
○ Binary : 11000000
○ Decimal : 168
○ Binary: 10101000
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128
64
32
16
8
4
2
1
192-128=64
64-64=0
0
0
0
0
0
0
1
1
0
0
0
0
0
0
128
64
32
16
8
4
2
1
168-128=40
40-64=N/a
40-32=8
8-16=N/a
8-8=0
0
0
0
1
0
1
0
1
0
0
0
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➢ Subnet Mask
○ 32-bit binary number
○ Applied to IP addresses
○ Divides network portion (ID) and host portion (ID)
○ All hosts on a network must have the same subnet mask
○ Comprised of contiguous 1 bits
○ 1 bits are a part of the network identifier
○ 0 bits are a part of the host identifier
➢ Binary ANDing
○ 0 ANDed to 1 = 0
○ 1 ANDed to 0 = 0
○ 1 ANDed to 1 = 1
➢ Special Addresses
○ Automatic private IP Address (APIPA)
○ 169.254.x.y
○ No DHCP server
○ Cannot communicate in WAN, only local communication
➢ Loopback address
○ 127.0.0.1
○ Used for testing
➢ IPv4 Classes
Class
Range
First Octet Binary
Default Subnet Mask/CIDR
Class A
1.0.0.0 – 126.255.255.255
00000000-01111111
255.0.0.0 or /8
Class B
128.0.0.0 – 191.255.255.255
10000000-10111111
255.255.0.0 or /16
Class C
192.0.0.0 – 223.255.255.255
11000000-11011111
255.255.255.0 or /24
Class D
224.0.0.0 – 239.255.255.255
11100000-11101111
Multicast Range
Class E
240.0.0.0 – 255.255.255.255
11110000-11110111
Experimental
Private IPv4 Addresses
Class
Range
Class A
10.0.0.0
Class B
172.16.0.0-172.31.255.255
Class C
192.168.0.0-192.168.255.255
➢ ICANN registers and controls IP addresses
➢ Types:
○ Public addresses
○ Private addresses
IP Addresses - IPv6
➢ https://www.cisco.com/en/US/technologies/tk648/tk872/technologies_white_paper0900aecd8026003d.pdf
➢ https://www.ipv6.com/general/ipv6-addressing/
➢ https://www.computernetworkingnotes.com/networking-tutorials/ipv6-address-types-format-explained-with
-examples.html
➢ https://whstatic.1and1.com/help/CloudServer/EN-CA/d857940.html
➢ 2 to the power of 128
➢ 128-bit addresses
➢ Divided into 8 16-bit blocks
➢ Colon hexadecimal notation
➢ Abbreviation techniques
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○ Use double colon for ONE continuous blocks of zeros
○ Leading zeros can be removed
○ 2001:0db8:85a3:0000:0000:8a2e:0370:7334 - Full
○ 2001:db8:85a3::8a2e:370:7334 - Abbreviated
Slash notation for network and host identifier
○ 2001:db8:85a3::8a2e:370:7334/64
○ /64 will tell you how many bits are part of the network ID
○ First 64 bits are network ID last 64 bits are the host ID
Types
○ Global (2000::/3)
○ Unique local (FC00::/7) - PRIVATE
○ Link-local - (FE80::/10) - APIPA
More efficient routing
Eliminates broadcast communication
Communication Types:
○ Broadcast - One-to-all
○ Unicas - One-to-one
○ Multicast - One-to-many
IP Commands
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The ipconfig /all command will display all the TCP/IP settings for the computers
The ipconfig /registerdns command registers the computer's DNS host name with the DNS server
The ipconfig /displaydns command displays the contents of the computer's DNS cache
The ipconfig /renew command will renew the client's DHCP lease
The ipconfig /release command will release the client's DHCP lease
The ipconfig /showclassid command will display the DHCP class ID assigned to the client computer
The ipconfig /setclassid command will configure the DHCP class ID for the client computer
The ipconfig /flushdns command will flush the contents of the client computer’s DNS cache
Network Configuration Services
➢ Static addressing
○ Manual process
○ Administratively intensive
○ Prone to errors
○ Ip addresses do not change
○ Good for servers such as email servers, firewalls, routers, etc
➢ Dynamic addressing
○ DHCP Server automatically configures IP addresses
➢ D.O.R.A. lease process
○ Discovery
■ Client sends out request for IP addresses
○ Offer
■ DHCP server responds with IP addresses
○ Request
■ Client requests that IP addresses
○ Acknowledge
■ DHCP server leases that IP addresses to the client
○ IP addresses are leased for an amount of time
○ IP addresses can also be reserved for one MAC addresses
➢ DNS
○ Mapes user-friendly names to IP addresses
➢ DNS hierarchy
○ Root Servers ○ Top-level domain servers (TLD)
○ Second-level domain servers (SLD)
○ Hosts
○ Website DNS is read right to left
➢ FQDNs Gateways
○ Fully qualified domain name
○ Host name plus domain name = fully qualified domain name
○ web01.mycompany.com
○ Hostname = web01.
○ Domain name = mycompany.com
➢ VPNs
○ Creates a virtual point-to-point link
○ Allow for protected communications across public networks
○ Connects two or more local area networks (LANs)
○ Keep people from getting information
➢ VLANs
○ Virtual local area network
○ Allows switch to act like multiple switches
○ Devices can only communicate to other devices within the same VLAN
○ Better performance, security purposes
Cabling Standards
Cabling Standards
Note* - IEEE standards for LAN
IEEE Standard for Ethernet is 802.3
Ethernet Cable Standards (TIA/EIA Categories)
○ https://www.elandcables.com/the-cable-lab/faqs/faq-what-are-the-ethernet-standards
➢ TIA 568A and 568B
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➢ Fiber Cabling Standards
○ https://www.cablinginstall.com/home/article/16467353/standards-make-fibercable-specification-easi
er
➢ Fiber termination standards
○ https://www.ad-net.com.tw/16-types-fiber-optic-connectors-choose/
➢ Twisted Pair Cabling
○ 8 wires twisted into 4 pairs
○ Used for ethernet connections
○ Twists help improve resilience against EMF
○ Types:
■ UTP - Unshielded Twisted Pair
■ STP - Shielded Twisted Pair (shield further increase resiliency to EMF)
○ PVC vs Plenum
■ Plenum is used for HVAC system
● Not toxic when burned
■ PVC is toxic when burned
○ Termination standard
■ RJ-45 connector is the end of the twisted pair
■ 568A standard
■ 568B standard
■ 8p8c 8pin8conductor
➢ Cat Cabling Standards
○ Cat 3
■ Speed: 10 Mbps
■ Distance: 100m
■ Implementation: 10BASE-T
○ Cat 5
■ Speed: 100 Mbps
■ Distance: 100m
■ Implementation: 100BASE-T
○ Cat 5e
■ Speed: 350 Mbps
■ Distance: 100m
■ Implementation: 1000BASE-T
○ Cat 6
■ Speed: 1 Gbps
■ Distance: 100m
■ Implementation: 1000BASE-T
○ Cat 6a
■ Speed: 1 Gbps+
■ Distance: 100m
■ Implementation: 10GBASE-T
○ Cat 7
■ Speed: 1 Gbps+
■ Distance: 100m
■ Implementation: 10GBASE-T
➢ BASE standards
○ 10BASET
○ 10 = Transmission Speed (10 Mbps)
○ BASE = Signaling Type (Baseband)
○ T = Media Type (Twisted Pair)
➢ Coaxial Cabling
○ Audio and video transmission
○ Central copper conductor
○ Braided
○ Solid
○ Dielectric coating
○ Outer insulating jacket
➢ Coaxial Cabling Standards
○ RJ-59
■ Core: Thin
■ Termination: 75 Ohms
■ Implementation: Older CATV
○ RJ-6
■ Core: Thick
■ Termination: 75 Ohms
■ Implementation: Modern CATV
➢ Coaxial Cabling Termination Types
○ BNC connector - twist to lock
○ F connector -
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○ T connector- connects BNC and F connector
Fiber Modes
○ Multimode fiber cable
■ Shortest fiber length
■ Multiple light sources
■ 50 or 65 micron core
■ 125 micron outer shield
○ Singlemode
■ Longest fiber length
■ Single light source
■ 10 micron core
■ 125 micron outer shield
○ Termination Standards
■ ST connector - standard (straight) tip
● Older connector
■ SC connector - subscriber (standard) connector
■ LC connector - Lucent connector (little connector)
● Greater port density
● Current standard
Cat5 – Up to 100 meters and 100 Mbps
Cat6 – Up to 100 meters and 10 Gbps
ThinNet – Up to 185 meters and 10 Mbps
ThickNet – Up to 500 meters and 10 Mbps
Multi-mode fiber – Up to 500 meters and 10 Gbps
Single-mode fiber – Up to 40 kilometers and 10 Gbps
Network Adapter Configuration
➢ Wired or Wireless adapter
➢ MAC addresses are used to identify devices on the network
○ 6-byte or 48-bit address
○ Components:
■ OUI (Organizational unique identifier)
■ NIC (Network interface card)
■ 00-01-12-AA-BB-CC
■ First 3 bytes are OUI last 3 bytes are NIC
■ A MAC address is a 12-digit hexadecimal number
➢ TCP/IP Settings
○ Static vs Dynamic
○ IPv4 Settings
■ IP address
■ Subnet mask
■ Default gateway
○ Verify connectivity
➢ Communication Settings
○ Half vs Full Duplex
➢ Wireless adapter configuration
○ Enable wireless adapter
○ Discover wireless network (SSID, service set id)
○ Select wireless network to join
○ Enter passphrase
○ Join or connect network
○ Verify
SOHO Connectivity Devices
➢ Small Office Home Office
➢ DMZ
○ Demilitarized zone
○ Allows internet to get public access to a specific resource without access to the LAN
➢ NAT
○ Network Address Translation
○ Maps privates IP address to public IP addresses
➢ QoS
○ Quality of Service
○ Giving the exact amount of bandwidth needed for a application
➢ Multifunctioning devices
○ Router
○ Switch
○ Access Point
○ Port forwarding
Network Troubleshooting
➢ No connectivity
Wireless
■ Proximity to access point
■ Disabled wireless adapter
■ Right passphrase
■ Appropriate Drivers
○ Wired
■ Check cables
■ Network adapter failure
■ Power
■ TCP/IP settings
Intermittent connectivity
○ Wireless
■ Proximity
■ Antenna placements
■ EMI
■ Obstacles
■ Bandwidth overload
○ Wired
■ Bandwidth overload
■ ISP issues
■ Cables are damaged
Low RF signal
○ Proximity to access points
○ Obstacles
○ Antenna placement
SSID not found
○ Network name not found
○ Not broadcast
○ Access point is off
○ Access point is not in range
Slow transfer speed
○ Congestion
○ EMI
○ Old connectivity device
IP conflict
○ Falls back to the APIPA address
APIPA/link-local
Unavailable resources
○ Internet
Local Resources
○ Shares
○ Printers
○ Email
Software Utilities
○ ipconfig / ifconfig / ip addr
○ ping
○ nslookup / dig
○ tracert / traceroute
No connectivity – When there is no network connectivity, it is usually either the computer's hardware or the
network hardware. Check the network cabling, the network adapter, and the configuration of the network
adapter. For a wireless network, check the wireless card and its configuration.
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➢ APIPA/link-local address – An Automatic Private IP Addressing (APIPA) address is used when a computer
cannot communicate with a DHCP server. If a computer has been issued an APIPA address, the computer will
be unable to communicate with computers that have been issued addresses by the DHCP server. In this
situation, check to make sure that the DHCP server is functional and that the DHCP server has enough IP
addresses for its clients' needs. Make sure that all routers function as DHCP relay agents. Finally, ensure that
the computer's hardware is functional and allows it to connect to the network. A link-local address is IPv6's
version of APIPA. As with APIPA, a link-local address will only allow the client computer to connect to
computers and other devices on the same subnet.
➢ Limited connectivity – In this situation, a computer can connect to the network but cannot access a specific
resource on the network. The problem could be because the user does not have permission to access the
resource. If you can ping the resource but cannot access the resource by its host name, the DNS server could
be down. The problem could lie with the remote resource. See if other computers can connect to it.
➢ Local connectivity – This problem arises when a computer can connect to local resources but not to resources
outside the local subnet. This is usually due to an incorrect subnet mask, an incorrect default gateway
address, or a router problem. Check the TCP/IP settings for the computer's NIC. Check the connectivity to the
router.
➢ Intermittent connectivity – This problem can be hardware or software related. Check the network cable and
the NIC and its settings. Ensure that the DHCP and DNS servers are fully functional. If using wireless, check for
radio frequency interference (RFI).
➢ IP conflict – An IP address can be used by a single network host. If an IP address is duplicated on the network,
one or possibly both the computers will not be able to communicate on the network. This problem most often
occurs in situations where static IP addresses are used. You need to locate one of the computers involved in
the conflict situation and change its IP address. If the computers are both using dynamic addressing, you can
use the ipconfig /release command on one of the computers.
➢ Slow transfer speeds – This is usually caused by interference, incorrect cabling, a malfunctioning NIC, router
misconfiguration, or switch misconfiguration. If only one client is experiencing the problem, check that
computer's cabling and NIC. You only need to check for interference, router misconfiguration, or switch
misconfiguration if more than one client is experiencing this problem.
➢ Low RF signal – This wireless issue occurs because radio transmissions have a limited maximum distance. This
will require either moving the wireless router and wireless client so that they are closer together or increasing
the signal strength. In many cases, objects can cause obstruction or interference. Performing a site survey can
help you determine these issues.
➢ SSID not found – If a computer cannot find a Set Service Identifier (SSID), which is the identifier for a wireless
network, then it is usually either due to the wireless access point being turned off or the SSID being changed.
Try rebooting the wireless access point. Also, check the wireless access point to ensure that it is using the
same SSID
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