[MUSIC PLAYING] DEVAN SRI-THARAN: My
name is Devan Sri-Tharan. I've been working
in IT for 10 years. I'm a corporate
operations engineer at Google, where I get to
tackle challenging and complex IT issues. I'm really passionate
about IT infrastructure, but you can't understand
infrastructure until you understand hardware. So let's dig in. In IT, hardware is an
essential topic to understand. You might find yourself
replacing faulty components or even upgrading an entire
fleet of machines one day. By the end of this
lesson, you'll be able to describe all the
physical parts of a computer and how they work together. You'll even be able to
build your own computer. Once you figure out
how one computer works, you'll be able to understand
how any type of computer works. Excited? I am. Let's get started. [MUSIC PLAYING] Let's face it, computers
are everywhere. You come into contact with them
at home, work, the airport, the grocery store. You're using some type of
computer to take this course. You know what? There's probably one in
your pocket right now. While computers are complex
and can seem daunting to learn, they ultimately just calculate,
process, and store data. In this lesson, we're
going to take a peek at what's inside of a computer. We'll spend the next
few lessons explaining how each of these components
work, but for now, let's check out a typical desktop setup. Desktops are just computers that
can fit on or under our desks. So here we have a monitor,
a keyboard, a mouse, and a desktop. Sometimes, you might even add a
webcam, speakers, or a printer setup. We'll call these physical
components hardware. Let's take a look at the
back of the computer. You can see common
connectors here, the power outlet here,
and the common ports here. Ports are connection points
that we can connect devices to that extend the
functionality of our computer. We'll go into detail
about the ports you see here in a later lesson,
but here's a quick rundown. We have a port here to
connect to a monitor and a few ports here to plug
your keyboard and mouse. There's another important
one here for our network connection. With just these ports,
we're able to have the basic functionality to
browse the web and much more. Things look pretty
similar on a laptop. Here are some of the same
ports, a built-in monitor, and a keyboard. There are also
physical components inside the laptop case that
are hidden for portability. Once you figure out
how one computer works, you can figure out how
any other computer works. OK, this is my favorite part. Let's open up this desktop
and take a deeper look. Let me first clean up my desk. Get ready for it. Whoa, it looks pretty
complicated, but that's OK. We'll take you through it. Let's start with a
quick tour, then we'll dive deeper into each of these
parts in the next lesson. Right here, this component is
the CPU, or Central Processing Unit, which is covered
by this heat sink. You can think of the CPU as
the brain of our computer. The CPU does all the
calculations and data processing. It communicates pretty
heavily with this component right here-- RAM, or Random Access Memory. RAM is our computer's
short-term memory. We use this component
when we want to store data temporarily--
like let's say you're typing something into
a chat or a piece of text in a word processor. This information is
stored in the RAM. Don't worry, we'll cram
in more details on RAM in the later lesson. When we want to store
anything in long-term memory, we use this component here-- the hard drive. The hard drive holds all our
data, which can include music, pictures applications. Let me show you something
else interesting. Have you noticed
this large slab here? This is our motherboard. It holds everything in place
and lets our components communicate with each other. It's the foundation
of our computer. You can think of the motherboard
as the body or circulatory system of the
computer that connects all the pieces together. The last component
we'll talk about is our power supply,
which converts electricity from our wall
outlet onto a format that our computer can use. You know what's interesting? All these components make
up most computers, even a mobile phone. While it might look very
different from your laptop, a mobile phone just uses a
smaller version of the hardware that we saw in the
desktop and laptop today. So now that we've covered the
basic anatomy of a computer, we'll go over each of
these components in-depth in the next few lessons. Understanding how
computer hardware works is a really helpful
skillset in IT support. Since an IT department
maintains the hardware that a company uses,
a solid understanding of these computer internals
will come in handy when troubleshooting
hardware-related problems. And taking things apart
to see how they work is just super fun. [MUSIC PLAYING] Before we get our hands
dirty with learning how to build a computer,
let's talk theory first. In an earlier lesson,
we talked about binary and how computers
perform calculations. Remember that our
computer can only communicate in binary using
1's and 0's Our computers speak in machine language,
but we, of course, speak in human languages, like
English, Spanish, Mandarin, Hindi-- you get the idea. If we want to communicate
with our machines, we have to have some sort
of translation dictionary, just like if I wanted to
say something in Spanish, I'd look it up in an
English-to-Spanish dictionary. Well, our computers have a
built-in translation book. In this lesson,
we'll dive deeper into how our computer translates
the information we give it into instructions
that it understands. Right now, you're probably using
a web browser, music player, text editor, or something
else in your computer. We interact with these
applications on a daily basis. They're referred to as programs. Programs are basically
instructions that tell the computer what to do. We typically store programs on
durable media like hard drives. You can think of programs
like cooking recipes. We'll keep these recipes all
stored together in a cookbook just like apps stored
in a hard drive. Now, we want to
make a ton of food. So we hire a chef to
follow our recipes and whip up something good. The faster our chef works,
the more food she'll prepare. The chef is our CPU. She processes the recipes we
send her and makes the food. Our chef works super fast-- so fast that she can cook
faster than she can read, so we take a copy of the
recipes and put them into RAM. Remember that RAM is our
computer's short-term memory. It stores information
in a location our CPU can access
it faster than it could with our hard drive. Now we can give
our chef one or two recipes at a time
instead of reciting the entire cookbook to her. OK, now let's say I want to
make a peanut butter and jelly sandwich. I see a pretty good recipe and
send it to our chef to make. Remember that our chef needs
these instructions quickly, so I don't send her
the entire recipe. I send her one line at a time. One-- get two slices of bread. Two-- put peanut
butter on one slice. Three-- put jelly
on another slice. Four-- combine the
two slices of bread. Now, let me throw one
more thing at you-- our chef can only communicate
with us in 1's and 0's. So instead of sending
something readable, like the recipe for a peanut
butter and jelly sandwich, we have to send her
something like this. In reality, this process is
a little more complicated. Our CPU is constantly
taking instructions and executing them. These instructions
are written in binary. But how do they travel
around the computer? In our computer, we have
something called the External Data Bus, or EDB. It's nothing like a bus at all. It's a row of wires
that interconnect the parts of our computer,
kind of the veins in our body. When you send a voltage
to one of the wires, we say the state of the wire
is on, or represented by a 1. If there's no voltage, then
we say that the state is off, represented by a 0. This is how we send
around our 1's and 0's. Sound familiar? In the last lesson, we
talked about how transistors help us to send voltages. Now, we know how
our bits physically travel around the computer. The EDB comes in
different sizes-- 8-bit, 16-bit, 32, even 64. Can you imagine if you
had 64 wires going? You can move around
a lot more data. Right now, we're
just going to stick with using an EDB with
8 bits in our examples, sending 1 byte at a time. OK, so now our CPU
is receiving a byte and it needs to get to work. Inside the CPU, there are
components known as registers. They let us store the data
that our CPU works with. If, for example, our CPU
wanted to add two numbers, one number would be
stored in a register A. Another number
would be stored in register B. The result
of those two numbers would be stored in register C. Imagine the register is one
of our chef's work tables. Since she has a place to
work, she can start to cook. To do so, she uses
a translation book to translate her binary into
tasks that she can perform. Let's jump back for a second. Remember that our programs are
copied into RAM for the CPU to read. RAM is memory that's
randomly accessed, allowing our CPU to read
from any part of RAM as quickly as any other part. We don't actually send
data from RAM over the EDB. There would be way
too much stuff. RAM can hold millions, even
billions of rows of data. Despite our sandwich
example, most of our recipes aren't simple at all. They can be thousands
of lines long. We want to process them,
and we don't actually go in any particular order. Since we can only send one
line of data through the EDB at a time, we need the help of
another component-- the Memory Controller Chip, or MCC. The MCC is a bridge between
the CPU and the RAM. You can think of it like a
nerve in your brain connecting to your memories. The CPU talks to the
MCC and says, hey, I need the instructions for step
number three of this recipe. The MCC finds the instructions
for step number three in RAM, grabs the data, and
sends it through the EDB. There's another
bus that's nothing like a bus involved in the
process called the address bus. It connects the CPU to
the MCC and sends over the location of the data,
but not the data itself. Then the MCC takes the address
and looks for the data, and then data is then
sent over the EDB. Believe it or not, RAM
isn't the fastest way we can get more data to
our CPU for processing. The CPU also uses
something known as cache. Cache is smaller
than RAM, but it lets us store data that we
use often and lets us quickly reference it. Think of RAM like a
refrigerator full of food. It's easy to get into,
but it takes time to get something out. On the flip side of that,
cache is like the stuff we have in our pockets. It's used to store recently
or frequently accessed data. There are three different
cache levels in a CPU-- L1, L2, and L3. L1 is the smallest
and fastest cache. If you're interested in
learning more about this, you can check out the
supplemental reading I've included right
after this video. So now we understand how our
RAM interacts with our CPU, but how does our CPU know
when a set of instructions ends and a new one begins? Our CPU has an
internal clock that keeps its operations in sync. It connects to a special
wire called a clock wire. When you send or receive
data, it sends a voltage to that clock wire to
let the CPU know it can start doing calculations. Think of our clock wires
as the ticking of a clock. For every tick, the CPU does
one cycle of operations. When you send a voltage
to the clock wire, it's referred to
as a clock cycle. If you have lots of data you
need to process in a command, you need to run lots
of clock cycles. Have you ever seen
a CPU in the store, and it has something
labeled 3.4GHz? This number refers to the
clock speed of the CPU, which is the maximum
number of clock cycles that it can handle in
a certain time period. 3.40 gigahertz is 3.4
billion cycles per second. That's super fast. But just because it
can run at this speed doesn't mean it does. It just means that it
can't exceed this number. Still, that number doesn't
stop some people from trying. There's a way you can exceed
the number of clock cycles on your CPU on
almost any device. It's referred to
as overclocking, and it increases the rate
of your CPU clock cycles in order to perform more tasks. This is commonly used to
increase the performance in low-end CPUs. Let's say you're a
gamer and you want to have better graphics
and less lag while playing. You might want to overclock
your CPU when you play the game. But there are cons to doing
this, like potentially overheating your CPU. You can read more
about overclocking in the next
supplementary reading. [MUSIC PLAYING] If someone asked
you to calculate the square root of 5,439,493,
would you do the math by hand? Unless you really love
tedious math problems, you'd probably use a calculator. Well, what about binary? Well, you probably wouldn't
calculate binary by hand, either. There's actually a very
powerful calculator right inside of your computer
that process binary for us. We've already discussed
this calculator in detail. Do you know what it is? It's our CPU, the
brain of our computer. In this video, we'll cover
the more practical aspects of the CPU. Remember that translation
book that I talked about in an earlier lesson? The CPU uses this to
translate and perform functions on our data. This translation book is
called an instruction set, which is literally just
a list of instructions that our CPU is able to run. Functions like
adding, subtracting, copying data are
all instructions that our CPU can carry out. Every single program
on your computer, while extremely
complex, is broken down into very small and
simple instructions found in our instruction set. Instruction sets are
hardcoded into our CPU. So different CPU manufacturers
may use different instruction sets, but they generally
perform the same functions. It's like how car
manufacturers build their engines differently, but
they all get the same job done. You'll probably work
with computer hardware as an IT support specialist,
replacing failed hard disks, upgrading RAM modules, and
installing video cards, so you need to be aware
of what's out there. You've probably heard of a
few popular CPU manufacturers or chipsets like Intel,
AMD, and Qualcomm. These CPU manufacturers
use different product names to differentiate
their processors, like Intel Core i7, AMD Athlon,
Snapdragon 810, Apple A8, and more. Now when you hear these terms,
you'll know what they mean. Each of these CPU manufacturers
have their strengths and weaknesses. If you are interested in
learning more about why some CPUs are more
popular than others, you can check out the
next supplemental reading. When you select your
CPU, you'll need to make sure it's compatible
with your motherboard-- the circuit board that connects
all your components together. Heads up, you can't just
buy a bunch of parts and expect them
to work together. There are different ways
CPUs fit on motherboards using different sockets. Your CPU might have lots of
tiny pins that either stick out or have contact points
that look like dots. Depending on your
motherboard, you need to make sure these CPUs
fit correctly in the socket. There are currently two
major types of CPU sockets-- Land Grid Array, also known
as LGA, and Pin Grid Array, also known as PGA. In an LGA socket
like this one, there are pins that stick
out of the motherboard. The socket size
may vary, so always make sure your CPU and socket
are compatible beforehand. When you purchase a
CPU or motherboard, it will tell you right on the
box what type of socket it has. Make sure your CPU and
motherboard socket also both match. If it's not listed
on the box, you can go to the manufacturer's
website, where it usually lists what types of
CPUs are compatible with the motherboard. The other type of socket
is the PGA socket, where the pins are located
on the processor itself. When we install our CPU, we
need to do a few things to it to keep it cool. Since it does a lot of work,
it's prone to overheating. We have to make sure to
include a heat sink, too, which takes the heat from our
CPU and dissipates it through a fan or another medium. There's one last thing I
want to call out about CPUs. If you purchase
a CPU, you'll see that it has either a 32-bit
or 64-bit architecture. What does that mean? Well, we know we can
process 8 bits in binary. Now, imagine how we can process
with 32 or even 64 bits. CPUs that have 32-bit
or 64-bit architecture are just specifying
how much data they can efficiently handle. You can read more
about the differences between 32-bit and
64-bit architecture in the next reading. For now, the main
takeaway is that the CPU is one of the most important
parts of the computer, so we have to make
sure it's compatible with all other components
and can perform well for our computing needs. [MUSIC PLAYING] Let's talk about RAM, our
computer's short-term memory. We use RAM to store data that
we want to access quickly. This data changes all the
time, so it isn't permanent. Almost all RAM is
volatile, which means that once we power off
our machines, the data stored in RAM is cleared. Remember that our computer
is comprised of programs. To run a program, we
need to make a copy of it in RAM so our CPU
can process it. When you see a new
phone or laptop that says it has 16 gig of RAM,
that means it can run up to 16 gigs of programs, meaning
you can run lots of programs at the same time. When you type in a
document, you're using RAM. If you've ever
had the misfortune of working on an important
presentation or paper and losing power,
you know the feeling you get when all of the
work you've done is lost. It's a total bummer. This happens to anything
with RAM, even video games. Have you ever gone
on a long campaign without saving, then right
as you get to a save point, the power goes
off on the console and all the progress you've
made is lost forever? It's no fun at all. You spend the next
hour or so deciding whether or not just to rage quit
the game completely and start all over from scratch-- not that this happened
to me or anything. That was just a friend. Anyway, all of this happens
because RAM clears its data when powered off. There are lots of types
of RAM, and the one that's commonly
found in computers is DRAM, or Dynamic
Random Access Memory. Where a 1 or a 0
is sent to DRAM, it stores each bit in a
microscopic capacitor. This is either
charged or discharged, represented by a 1 or a 0. These semiconductors are put
into chips that are on the RAM and store our data. There are also different
types of memory sticks that DRAM
chips can be put on. The more modern
DIMM sticks, which usually stands for Dual
Inline Memory Module, have different sizes
of pins on them. I should call out
we don't really buy RAM based on the number
of DRAM chips they have. They're labeled by the
capacity of RAM on a stick, like an 8-gig stick of RAM. After DRAM was created,
RAM manufacturers built something
called SDRAM, which stands for Synchronous DRAM. This type of RAM is synchronized
to our system's clock speed, allowing quicker
processing of data. In today's system, we
use another type of RAM called Double Data Rate
SDRAM, or DDR SDRAM for short. Most people refer to this
Ram as DDR, even shorter. There are lots of iterations
of DDR, from DDR1, DDR2, DDR3, and now DDR4. DDR is faster,
takes up less power, and has a larger capacity
than earlier SDRAM versions. The latest version,
DDR4, is the fastest type of short-term memory currently
available for your computer, and faster RAM means that
programs can be run faster and that more programs
can run at the same time. Keep in mind that
any RAM sticks you use need a compatible
motherboard with a different
number of pins aligned with the motherboard RAM slots. Just like with the CPU, make
sure that your motherboard is compatible with any
RAM sticks that you buy. Up next, we'll take a deep
dive into motherboards. [MUSIC PLAYING] Oh, the motherboard--
the foundation that holds our computer together. It lets us expand our
computer's functionality by adding expansion
cards, it routes power from the power supply, and
it allows the different parts of the computer to
communicate with each other. In short, it's a total boss. Every motherboard has a
few key characteristics. First is the chipset, which
decides how components talk to each other on our machine. The chipset on motherboards
is made up of two chips. One is called the northbridge
that interconnects stuff like RAM and video cards. The other chip is
the southbridge, which maintains our I/O, or
Input/Output, controllers like hard drives and USB devices
that input and output data. In some modern CPUs,
the northbridge has been directly
integrated into the CPU so there isn't a separate
northbridge chipset. The chipset is a key
component of our motherboard that allows us to manage
data between our CPU, RAM, and peripherals. Peripherals are the
external devices we connect to our computer,
like a mouse, keyboard, and a monitor. You will learn more
about peripherals in an upcoming lesson. In addition to the
chipsets, motherboards have another key
characteristic which allows the use of expansion slots. Expansion slots also
give us the ability to increase the functionality
of our computer. If you wanted to upgrade
your graphics card, you could purchase one and just
install it on your motherboard through the expansion slot. The standard for
an expansion bus today is the PCI Express,
or Peripheral Component Interconnect Express. A PCIE bus looks like a
slot on the motherboard, and a PCIE base expansion card
looks like a smaller circuit board. The last component of
motherboards that we'll discuss is form factor. There are different
sizes of motherboards that are available today. These sizes, or form
factors, determine the amount of stuff we can put in it and
the amount of space we'll have. The most common form
factor for motherboards is ATX, which stands for
Advanced Technology eXtended. ATX actually comes in
different sizes, too. In desktops, you'll commonly
see full-sized ATXs. If you don't want to
use an ATX form factor, you could use an ITX, or
Information Technology eXtended, form factor. These are much smaller
than ATX boards. For example, the Intel NUC uses
a variation of the ITX board which comes in
three board sizes-- mini ITX, nano
ITX, and pico ITX. When building your
computer, you will need to keep in mind what
type of form factor you want. Do you want to build
something smaller that can't handle
as much workload, or do you want a
powerhouse workstation that you can add lots
of functionality to? The form factor will
also play a role into what expansion slots
you might want to use. Understanding motherboards
and their characteristics can be a big plus when fixing
hardware issues since things like the type of RAM
module or processor socket are dependent on the
kind of motherboard they need to fit into. Let's say you're responding
to a ticket for a user who's having video problems. You don't want to make it
all the way to their desk only to realize the
graphics card you bought as a replacement doesn't
fit the motherboard their computer uses. You will learn more
about customer service and troubleshooting tactics
later on in this course, but for now, make sure
that your motherboard can fit any replacement or upgrade
that you want to implement. [MUSIC PLAYING] So before we get into
computer storage, we need to fill in some gaps. I'm referring to things like
gigabytes, bits, et cetera. But we actually
haven't talked at all about what those metrics mean. Sorry, I kind of
"gigabit" ahead of myself. As you might have guessed,
these terms refer to data sizes. The smallest unit of a
data storage is a bit. A bit can store
one binary digit, so it can store a 1 or 0. The next largest unit of
storage is called a byte, which is comprised of 8 bits. A single byte can hold a
letter, number, or symbol. The next largest unit is
referred to as a kibibyte, but we typically use
the term kilobyte. A kilobyte is made
up of 1,024 bytes. If you're curious why 1 kilobyte
refers to 1,024 bytes and not 1,000 bytes, you can
read more about that in the next
supplemental reading. For now, here's a quick
data conversion chart. How much does 500
gigabytes even mean? Let's take a look at the size
of an average music file, which is about 3 megabytes. On a 500-gigabyte
machine, that's approximately
165,000 music files. That's a lot of music. We store all of
our computer's data on our hard drive, which allows
us to store our programs, music, pictures, et cetera. Have you ever had an
issue with your computer and lost all the data that
was on your hard drive? Yeah, me too. It was the worst. This actually happens a lot,
and you'll probably encounter it as an IT support specialist. Make sure you back up
your data to be safe. This means you should copy
or save your data somewhere else just in case
something goes wrong and your hard drive crashes. That way, you won't
lose all your data. There are two basic hard
drive types used today-- Hard Disk Drives, or HDDs,
use a spinning platter and a mechanical arm to
read and write information. The speed that the
platter rotates allows you to read
and write data faster. This is commonly referred to as
RPM, or Revolution Per Minute. A hard drive with a
higher RPM is faster, so if you go out and
buy a hard drive today, you might see something like
a 500 gigabyte with 5,400 RPM. HDDs are prone to
a lot more damage because there are a
lot of moving parts. This susceptibility
to damage went away with a new type
of storage called Solid State Drive, or SSD. SSDs have no moving parts. Are you familiar
with a USB stick? SSDs operate in a similar way. The information is
stored on microchips, and data travels a
lot faster than HDDs. The form factor for
SSDs is also slimmer compared to their HDD cousins. Sounds great, doesn't it? So why doesn't
everyone use SSDs? Well, both have
their pros and cons. HDDs are more affordable, but
they're more prone to damage. SSDs are less risky when
it comes to losing data, but they're also more expensive. So you may not buy as much
memory storage in SSDs than what you can get in HDDs. Believe it or not, there are
even hybrid SSD and HDD drives out there. They offer SSD performance
where you need it for things like
system performance, such as booting your
computer, along with hard disk drives for less important
stuff, like basic file storage. There are a few interfaces
that hard drives use to connect to our system. ATA interfaces are
the most common ones. The most popular ATA drive
is the Serial ATA, or SATA, which uses one cable
for data transfers. SATA drives are hot-swappable--
great term, don't you think? It means you don't have
to turn off your machine to plug in a SATA drive. SATA drives move data faster
and use a more efficient cable, like this one, than
its predecessors. SATA has been the de facto
interface for HDDs today, but people quickly found
that using a SATA cable wasn't good enough for some
of the blazing-fast SSDs that were coming on the market. The interface couldn't
keep up with the speeds of the new SSDs, so
another interface standard was created called
NVM Express, or NVMe. Instead of using a cable
to connect your drive to your machine, the drive was
added as an expansion slot, which allows for greater
throughput of data and increased efficiency. [MUSIC PLAYING] In order to get our computer to
work, let's give it some power. Computers have a power supply
that converts electricity from your wall to
something usable. There are two types
of electricity-- DC, or Direct Current, which
flows in one direction, and AC, or Alternating Current, which
changes directions constantly. Our computers use
DC voltage, so we have to have a way to convert
the AC voltage from our power company to something we can use. That's what our
power supply does. It converts the AC we get from
the wall into low-voltage DC power that we can
use and transmit throughout our computer. So let's talk about
power supplies. I actually have one right here. Let me show you
how one looks like. Take it out right here. So most power supply units have
a fan, which is right in here. They also have voltage
information, which is normally listed underneath
or on the side, and cables like this one
to power your motherboard and a power cable. Have you ever plugged
one of your devices into the wall outlet
and fried your device? If you haven't,
you're really lucky. After completing this
lesson, hopefully you will know how to
avoid that situation. To understand electricity, let's
use the example of water pipes. Our sinks have a
faucet that's connected to a pressurized water tank. When we turn on the
faucet, water comes out. This is sort of how
electricity works. When we plug an appliance into
a wall outlet and turn it on, a flow of electricity comes out. If we added more pressure
to our water tank, would more water come out of it? The higher the pressure, the
more water there will be. When it comes to
electricity, we refer to the pressure as voltage. So when I was on
vacation, to my surprise, when I plugged in a
120-volt appliance into a 220-volt
outlet, the power came bursting through
and fried my charger. If it was the other way around
and a 220-volt appliance was plugged into
120-volt outlet, I wouldn't have seen
the same outcome. I'll still be able to get
electricity, but slowly. This would be
similar to if a water tank was only half-pressurized. It would draw water, but slowly. In some cases, though,
this can deteriorate the performance of the
device and cause damage in the long term. As a general rule, be sure
to use the proper voltage for your electronics. We refer to the
amount of electricity coming out as
current, or amperage, and it's measured in amps. We can think of amps
as pulling electricity as opposed to voltage,
which pushes electricity. Amps will pull as much
electricity needed, but voltage will just give you everything. Look on the back of one
of your device chargers. You might see
something 1 or 2.1A. Charging a device with 2.1
amps will actually charge your device faster because it's
able to pull more current from a 2.1-amp than a 1-amp charger. Finally, the other
important part of the electricity that you'll
need to know is the wattage. Wattage is the amount of volts
and amps that a device needs. If your power supply has
too low of a wattage, you won't be able to
power your computer. So make sure you have enough. This doesn't mean that if you
have a large power supply, you'll overpower your computer. Power supplies just give you the
amount that your system needs. It's best to err on the side
of large power supplies. You can power most basic
desktops with a 500-watt power supply, but if you're
doing something more demanding on your computer like
playing a high-resolution video game or doing a lot of video
production and rendering, you will likely need a bigger
power supply for your computer. On the other hand, if all you're
doing is just browsing the web, the power supply that comes with
your computer should be fine. All kinds of issues are
caused by a bad power supply. Sometimes, the computer
doesn't even turn on at all. Since power supplies
can fail for lots of reasons, like burnouts,
power surges, or even lightning strikes, knowing how to
diagnose power issues and replace a
failed power supply is a skill every IT
support specialist should have in their toolbox. [MUSIC PLAYING] So let's take a look at the
back of our computer again. Here you'll see lots
of connectors or ports. We can plug in different
objects like a mouse, keyboard, and a monitor. These are known as peripherals. A peripheral is
basically anything that you connect to your
computer externally that adds functionality. You've probably used
USB devices before. USB, also known as
Universal Serial Bus, devices are the most popular
connections for our gadgets. USB has gone through lots
of changes since inception. You'll most commonly
encounter USB 2.0, USB 3.0, and 3.1 in today's system. Here's a quick rundown of
the different versions. USB 2.0 transfers speeds of
480 megabytes per second. USB 3.0 transfers speeds
of 5 gigabytes per second. USB 3.1 transfers speeds
of 10 gigabytes per second. In the chart, let's pay
attention to the details-- using Mb/s instead of using MB
to reference transfer speed. These are actually
different units. MB is megabyte, or
unit of data storage, while Mb/s is a megabit
per second, which is a unit of data transfer rate. People often
mistake speeds of 40 megabit a second to mean
that you can transfer 40 megabytes of data per second. Remember that 1 byte is 8 bits. So to transfer a 1-megabyte
file in a second, you need an 8 megabits per
second connection speed. So to transfer 40 megabytes
of data in a second, you would need a transfer speed
of 240 megabits per second. You'll also need compatible USB
ports to go with your devices. If you connect a USB 2.0
device into a USB 3.0 port, you won't get 3.0
transfer speeds, but you can still use the port
since it's backward compatible, meaning older hardware will
work with newer hardware. The ports are easy
to differentiate. Let me show you. In general, USB 2.0 are
black, and USB 3.0 are blue, and 3.1 ports are teal. This may change depending
on manufacturers. There are lots of types
of USB connectors, and you can read
about all of them in the supplemental reading
right after this video. Check it out. Back to USB connectors,
the most recent one is a type-C connector,
which is meant to replace many peripheral connections. It's quickly becoming
a universal standard for display and data transfer. In addition to USB
peripherals, you should also be aware
of display peripherals. There are some common
input standards to know. Most computer monitors
will have one or more of these connections, but you
might encounter some older standards, too. DVI-- DVI cables generally
just output video. If you need to hook up a
monitor or projector for a slide presentation and you want audio,
too, you may be out of luck. Instead, you want to look at
one of the following cables. HDMI-- this has
become a standard in lots of televisions
and computers nowadays and outputs both
video and audio. Another standard that's become
popular among manufacturers is a DisplayPort, which also
outputs audio and video. In addition to audio
and video, USB Type C can also do data
transfer and power. As an IT support
specialist, you'll work with peripherals
like USB devices and display devices a lot. Now you'll be able
to distinguish between the major types. [MUSIC PLAYING] OK, now we've seen
all the key components to get our computer running. The last thing
we'll go over is how our devices talk to each other. We know how programs execute
from our hard drive to our CPU, but how do other things like a
mouse click or a keyboard press get sent to our
CPU for processing? These are fairly basic devices. They don't contain
any instructions that our CPU knows how to read. If you just clicked on a
key from your keyboard, you'd only be sending
a byte to the CPU. The CPU doesn't
know what this is because it doesn't
have instructions on how to deal with it. Turns out our devices also
use programs to tell the CPU how to run them. These programs are called
services or drivers. The drivers contain
the instructions our CPU needs to
understand external devices like keyboards,
webcams, printers. Our CPU doesn't know that
there is a device that it can talk to, so
it has to connect to something called the BIOS,
or Basic Input/Output Services. The BIOS is software
that helps initialize the hardware in our computer
and gets our operating system up and running. Unlike the programs,
you're probably used to running, like, a web
browser or operating system. The BIOS isn't stored
on a hard drive. Our motherboard stores the BIOS
in a special type of memory called the Read-Only
Memory chip, or ROM chip. Unlike RAM, ROM is
nonvolatile, meaning it won't erase the data if
the computer is turned off. Once the operating
system loads, we're able to load drivers
from nonessential devices directly from the hard drive. In today's system,
there's another player for bios called UEFI, which
stands for Unified Extensible Firmware Interface. UEFI performs the same function
of starting your computer as a traditional BIOS,
but it's more modern and has better compatibility
and support for new hardware. Most hardware out there today
comes with UEFI built-in. Eventually, UEFI will
become the predominant bios. When you turn on a computer,
you might notice a beeping-- [BEEP] --from time to time. Our computers run a test to
make sure all the hardware is working correctly. This is called a Power-On
Self Test, or POST, and the BIOS runs it when
you boot up your computer. The POST figures out what
hardware is on the computer, so it happens before the
BIOS initializes any hardware or loads up essential drivers. If there's an issue with
anything at that point, there's no way to
display it on the screen since things like the video
driver haven't been loaded. Instead, the
computer can usually produce a series of beeps
almost like Morse code which will help identify the problem. Different manufacturers
have different beep codes. So if your computer successfully
boots up, you may hear a-- [BEEP] --single beep. If you hear two beeps-- [TWO BEEPS] --it could mean a POST error. It's best to refer to
your motherboard manual to find out what
each code means. Also, you should know
that not all machines have built-in speakers, so don't
worry if your computer boots without a beep. If it does have a
built-in speaker, being able to distinguish
what the beep codes mean is an extremely
helpful tool when troubleshooting boot issues. One last thing-- we'll
discuss our BIOS settings. There's a special chip on our
motherboard called the CMOS chip. It stores basic data about
booting your computer, like the date, time, and
how you want it to start up. You can change these settings
by booting into CMOS or BIOS Settings menu. It varies on
different computers, but usually, when you
boot the computer, there will be a
quick screen that tells you what button to push
to get into the settings. From there, you can
change the basic BIOS settings of your machine. In at IT support role, you
might interact with the BIOS more often than you think. BIOS settings control
which devices to boot to, and in an IT role,
you might need to change the settings
more often than not. A frequently performed IT task
is the reimaging of a computer. The term refers to a
disk image which is a copy of an operating system. So the process of
reimaging involves wiping and reinstalling
an operating system. This procedure is
typically performed using a program that's stored
on some external device like a USB memory
stick or a CD-ROM or even a server accessible
through the network. To access these programs
and perform the reimage, you need to use the BIOS to
tell the computer to boot up from that external device. SPEAKER: Congratulations
on finishing this lesson from the Google IT
Support Certificate. Access the full experience,
including job search help, and get the official
certificate by clicking the icon or the link in the description. Watch the next lesson in
the course by clicking here, and subscribe to our
channel for more lessons
