# How To Assemble A Desktop PC/Assembly

Now that you have selected your parts, you get to what is arguably the
most fun part of the process: putting the parts together.

## Tools and equipment

!Combination flanged-hex/Phillips-head screw used in
computers
You won't need many tools to assemble your computer, in fact the only
one you must have is the screwdriver, but if you can get most of the
following together, you'll find things go a little easier.

### Basic tools

Before you begin building or refitting a computer, you should have some
basic tools:

1.  #2 Phillips-head (cross-shaped) screwdriver
2.  Needle-nose pliers
3.  A large level working space
4.  Brush

!An anti-static wrist strap with
crocodile
clip.

### Optional, but useful tools

Some other tools and equipment can come in handy as well, such as:

1.  Anti-static Wrist Strap (**Highly Recommended**)
2.  An Anti-static mat can help provide a safe place to set components
    down.
3.  Spring action parts grabber.
4.  Electrical tape
5.  Wire or nylon ties
6.  Flashlight, preferably hands-free
7.  A second, working computer to swap parts, look for tips, ask for
    help on-line, download drivers and patches, etc. - very useful
8.  A can of compressed air - useful when working with older parts that
    have collected dust. A better alternative but also more costly, is a
    vacuum cleaner designed for cleaning electronics.
9.  Magnetic screwdriver
10. Zip ties or velcro ties for cable management

## Preparation

Proper preparation is the key to a successful build. Before you begin,
make sure you have all the tools you will need, secure a clear, well-lit
workspace, gather all the components you'll be using and unpack them one
at a time, verifying that everything that is supposed to be there is
actually present. At this point you should leave the parts themselves in
their protective anti-static bags, and assemble all the accompanying
manuals. Now I know you want to get started, but trust me, *read the
manuals*, check the diagrams, make sure you understand where each part
goes and how it attaches. If there is anything you don't understand, now
is the time to do a little extra Internet research or call the
manufacturer with your questions.

Find a dry, well-ventilated place to do your work. You should have
plenty of light and if possible, you should choose an area without
carpet on the floor, as carpet tends to generate a lot of static. An
unfurnished basement is a good work location.


### Safety precautions

1.  Static electricity is the biggest danger to the expensive parts you
    are about to assemble. Even a tiny shock, which is much too small
    for you to feel, can damage or ruin the delicate electronic traces
    many times smaller than a human hair that make up your CPU, RAM and
    other chips. It's important to use your anti-static wrist strap to
    prevent damage to these components. Once you have the power supply
    installed in the case, clip the end of the wrist strap to the
    outside of the power supply. (Never plug your computer in while you
    are connected to it by a wrist strap.) This will ensure that you,
    the case and the power supply are all connected to a common ground,
    in other words there will be no inequality of charge that will allow
    a spark to jump from you to the case. It's also helpful to have an
    anti-static mat to set the case and other components on.
2.  Nobody but you is at fault if you shock your components with static
    electricity. Make sure that you take the precautions in the previous
    paragraph to ground yourself from static electricity. (Note: if you
    really must work on a computer and have not got proper anti-static
    equipment, it is *usually* OK if you make sure that you do not move
    about much; are not wearing any static-prone clothing; handle
    components by the edges; and regularly (once a minute or so), touch
    a grounded object.). The *case metal* of your PC\'s power supply
    will usually be a suitable grounded object (please note that the
    metal must be unpainted). As noted above, touch it every few minutes
    while you are working on your PC if you haven't got a wrist strap.
3.  Turn off your computer and switch off your Power Supply at the wall
    before installing or removing any components - if power is flowing
    to components as they are installed or removed, they can be
    seriously damaged. In order to have a computer properly grounded,
    you need it plugged in at the wall but turned off at the power
    supply and at the wall. The neutral line may be earthed.
4.  Never cut the grounding pin off your power cord. This \"safety
    ground\" stands between you and potentially lethal voltages inside
    the power supply.
5.  Be wary of sharp edges! Many lower-end PC cases have sharp,
    unfinished edges. This is especially so on interior surfaces, and
    where the case has been cut or punched-out. Use care and take your
    time to avoid cutting your hands. If your case has this problem, a
    little time with some sandpaper before you begin construction can
    spare you a lot of pain. Be extra careful not to cut yourself when
    installing the I/O Shield.
6.  Dismantling discrete electronic components such as your Power Supply
    or Monitor is dangerous. They contain high voltage capacitors, which
    can cause a severe electric shock if you touch them. These hold a
    charge even when the unit is not plugged in and are capable of
    delivering a fatal shock.

## Construction

Start by putting your case down on your work surface, with the case door
facing up, and open the case.

### Motherboard

!![](Mother_board_partial_name@ja.jpg "Kaunas_Priest_Seminary,_Kaunas,_Lithuania_-_Diliff.jpg"){width="800"
height="800"} Find the motherboard standoffs
(spacers) that should have come with the case. They are screws, usually
brass, with large hexagonal heads that are tapped so you can fasten
screws into the top. These hold the motherboard up off the case
preventing a short-circuit. Set these aside.

!A variety of io shields. Make sure to install this before installing
the
motherboard!.jpg "A variety of io shields. Make sure to install this before installing the motherboard!")

Remove the I/O Shield from the back of the case where the ports on the
back of the motherboard will fit, and put in the I/O Shield that came
with your motherboard. There may be small metal tabs on the inside of
this face plate, if so you may have to adjust them to accommodate the
ports on the back of the motherboard.

Some case styles make it difficult to install the motherboard or the CPU
with the power supply installed. If the power supply is in your way,
take it out and set it aside (we\'ll put it back in later).

Now locate the screw holes on your motherboard and find the
corresponding holes on the motherboard plate (or tray) in the case. Put
a standoff in each of these holes on the tray and position the
motherboard so that you can see the holes in the top of the standoffs
through the screw holes in the motherboard.

Now is the time to make sure the ports on the motherboard are mating
with the backplate you just installed, and make any necessary
adjustments. The small metal tabs are intended to make contact with the
metal parts of the connections on the back of the motherboard and ground
them, but you may have to bend these tabs a bit to get the ports all
properly mounted, this is where those needle-nose pliers may come in
handy.

Now fasten a screw through each of the motherboard screw holes into the
standoffs underneath. These screws should be snug but not tight, there
is no reason to torque down on them, hand tight is fine, otherwise you
can damage the motherboard.

Once the motherboard is installed, it is time to plug the other
components.

### CPU

!Some motherboard CPU sockets come with a plastic protector. This
should be removed before the CPU is inserted, and saved for
later.
!An example of a Intel CPU socket,
LGA2066.
!An AM4 socket for AMD
processors_02.jpg "An AM4 socket for AMD processors")

Installing the CPU, and the CPU's heat-sink
and fan, are by far the most difficult steps you'll have to complete
during your build. Here, more than anywhere else, it will pay to read
the instructions carefully, look at the parts, study the diagrams that
came with your CPU and/or third party cooling solution, and make sure
you thoroughly understand what you are going to do *before you try to do
it*. During the process, if anything does not seem to fit or make sense,
put the parts down and look things over carefully before you proceed.
Some operations, especially installing the heat-sink/fan combination,
can require pretty firm pressure, so don't be afraid to push a little
harder if you're sure everything is set up correctly.

The details of the installation process differ in slight but important
ways for each manufacturer's processors, and even within a
manufacturer\'s product line. Therefore, for these details, you should
rely on the instructions that are provided with the CPU.

The two things that go wrong the most often and most expensively
(minimum of a killed CPU, sometimes more) in building one\'s own
computer are both related to the CPU and its cooler:

1.  Switching the computer on \"just to see if it works\" before adding
    any CPU cooling unit. Without cooling, CPUs heat up at extreme rates
    (a CPU heats up anywhere between ten times and a thousand times as
    fast as a cooking area on your stove!). By the time you see the
    first display on the screen, your CPU will already be severely
    overheating and might be damaged beyond repair.
2.  Mounting the CPU cooler improperly. Read the instructions that came
    with your CPU and cooler very carefully and ensure you are using all
    components in the correct order and correct place.

!The base of a CPU heatsink. Remove any plastic film on the bottom of
the heatsink before
installation.
If you buy a third party cooling solution for your CPU make sure you get
one that is compatible with the CPU you have. \"Compatibility\" here
just means, \"Can you fit it in next to your RAM or whatever else is
sticking up in the neighborhood.\" Most brands come with multiple
mounting brackets that will suit many different chipsets, but it is best
to check for compatibility just in case.

After the CPU is installed in the socket and secured in place, it\'s
time to add thermal paste and then install the cooler. The plain metal
back of the CPU, which is what you\'re now seeing, is exactly matched by
the bottom plate of the cooler. You add thermal paste *only* on the CPU,
*never* on the cooler\'s surface. Very little is needed. The two flat
metallic surfaces will spread the paste between them, and it will spread
a bit more when it becomes hot. (The cooler surface may have a
protective piece of film over it; don\'t forget to remove it. But see
below for the possibility of \"thermal pad\" being supplied, instead of
paste. This is rare nowadays, but *read the instructions.*) A pea-sized
dot is the amount usually advised, though some people make a thin \"X\"
on the CPU surface, and some draw a line. (There are numerous videos on
YouTube advocating one or another, some with photos using glass plates.)
Don\'t overdo \-- you don\'t want paste squeezing out the edges. Some
people suggest spreading paste over the whole surface, then cleaning it
off with a razor blade, then adding the pea. The idea is to close
invisible imperfections in the metal. This is probably overkill, and
involves extra handling of the CPU, never a good idea. Try not to touch
the mating surfaces of the CPU and cooler \-- the oils from your skin
will impede heat transfer. You should receive a tube or applicator of
thermal paste in the CPU or cooler package, some CPU coolers come
pre-applied with thermal paste (such as AMD\'s wraith cooler), you can
optionally add your own to the CPU as extra or continue with the
pre-applied compound. If your CPU didn\'t come with thermal paste and
the cooler didn\'t have any pre-applied, thermal paste is readily
available from most computer retailers.

*See Arctic Silver
Instructions for more
info on how to apply and remove thermal paste/grease. (It was written to
be specifically for Arctic Silver paste, but the same techniques can be
applied to other brands of thermal paste.)*

If using a thermal pad supplied with your cooler, make sure you remove
any protective tape from the die just before installing and do not get
it dirty - and do not combine thermal pads with thermal paste, it is
either one or the other. Then, check that you install the cooler in the
right orientation and that you set it flat on the CPU die without
exerting undue pressure on any edges or corners - the latter can make
small pieces of the die break off, killing the CPU.

One option you may consider, before installing the heat-sink, is to
\"lap\" the heat-sink, which means to smooth out the bottom surface. To
do this, you will need a very flat surface; a piece of thick window
glass will work. Fasten your sandpaper on the flat surface, invert the
heat-sink on the sandpaper and sand in small circles, applying minimum
pressure. Check frequently and when you see a uniform pattern of
scratches, switch to finer grained sandpaper (the numbers go up as the
sandpaper is finer, so something such as 220 is coarse while 2000 will
be very fine.) Remember that you are not trying to remove any material,
just polish out surface irregularities. If you get it right, you should
have a surface which feels completely smooth to the touch (but don't
touch it, the oil in your fingers can cause corrosion of the fresh
surface) with a mirror finish. Some companies producing heat-sinks lap
the surface themselves, so if the surface already looks like a perfect
mirror, leave it alone. A lapped heat-sink is more effective as it will
have better surface contact with the chip.

Tighten the cooler using only the specified holding devices - if you did
everything right, they will fit. If they do not fit, check your setup -
most likely something is wrong. After mounting the cooler, connect any
power cables for the fan that is attached to the cooler.

As an aside to the instructions above, it has been my personal
experience that fitting the CPU and heat sink is best done on a
supportive surface (a telephone directory on a table in my case) prior
to installation, to avoid excessive flexing of the motherboard.

A last note: if something goes wrong and the cooler has to be removed
(like maybe you realize you didn\'t take the protective film off the
cooler surface), the paste will have to be removed from the CPU for the
restart. *Don\'t panic!* All it takes is a coffee filter (not paper
towels or anything else that will leave fibers) and a little isopropyl
alcohol (from the drugstore). Thermal paste removes easily with a little
gentle rubbing. Work from the outside edge in.

If you\'ve got the CPU and its cooler installed, and the motherboard in
the case, you're over the hump, there are just a few more easy pieces to
go before that momentous first power-up.

### Memory slots

!RAM module in a
socket{width="325"}

Next, you will need to install your RAM (random access memory). Find the
RAM slots on your motherboard; they will look something like the picture
on your left. To install the RAM modules, first push on the levers
(white plastic in the picture) on either side of the DIMM socket, so
that they move to the sides. Do not force them, they should move fairly
easily.

Put the RAM module in the socket. Line up the notch in the center of the
module with the small bump in the center of the RAM socket, making sure
to insert it the right way. Push down on the module until both levers
move up into the notches on the sides of the module. There should be a
small \"snap\" when the module is fully seated. Although this does
require a fair bit of force, do not overdo it or you may break the RAM
module.

!Motherboards often use color coded slots to indicate which slot
corresponds to which RAM
channel

Take a good look at your seated RAM, if one side seems to be higher than
the other, odds are it is improperly seated - take it out and try again.
As you handle the RAM, try not to touch the copper stripes you can see
along the bottom edge, as doing so is the best way to damage the part.

Start adding RAM at the slot labeled \"Bank 0\" or \"DIMM 1\". If you do
not have a stick in \"Bank 0\" or \"DIMM 1\" the system will think there
is no RAM and will not boot.

On motherboards with 4 slots, you\'ll see alternating colours. For
example, slot 1 is blue, slot 2 is black, slot 3 is blue, slot 4 is
black.

If you were to put 16 gigabytes of RAM in your personal computer, it is
best to use dual channel 8 GBx2 sticks. Put the first 8 GB stick in
**slot 1**, and put the 2nd stick in **slot 3** (the two slots that are
blue) - leaving slot 2 empty. This will give you better performance,
than putting 16 GB in slot 1 alone.

### Power supply

Installing your power supply is pretty straightforward, if it came with
your case it was pre-installed and if you took it out earlier to get the
motherboard in, now is the time to put it back. Otherwise a few moments
of screwdriver work will get the job done. Generally there will be a
bracket on the top of the case where the power supply is mounted and a
few screws used to fix it in place. Some cases place the Power Supply
differently, see the documentation that came with yours.

Some power supplies come with modular cables, so you can plug in only
those you'll be using; now is a good time to figure out what you'll need
and plug them in. Other power supplies have all the cables hardwired in,
you'll want to separate out the ones you'll need and neatly coil the
remainder somewhere out of the way.

If your power supply has a switch to select 115 V or 220 V make sure it
is set properly, this is important. Many newer power supplies can
automatically select and don't have such a switch.

Once you get the power supply installed make sure you check the
motherboard documentation carefully for the location of the power
sockets. You may then connect the main power, a 20 or 24 pin plug, into
the motherboard. There may also be an additional four or eight pin power
lead that needs to be plugged in to the motherboard (the CPU power
connector) usually located near the processor socket.

### Graphics card

!Insert the card into a matching slot on the
motherboard.{width="300"}

If your motherboard or CPU has a built-in graphics adapter you want to
use (like Intel HD Graphics), skip this section.

If you have a PCI Express video card, install it into the PCI Express
socket. Your computer will have a few of them, but choose the one which
is most convenient for you and will allow you to fit it into the desktop
case easily. Check your motherboard manual for instructions.

When your card is properly installed the line formed by the top of the
card will be exactly perpendicular to the motherboard, if one side seems
to be higher than the other, chances are that it is not fully inserted,
press a little harder on the high side or pull it out and try again.

### Installing drives

!A Serial ATA connector
!A M.2 slot on a motherboard with mounting posts
highlighted
Next install the storage drive and optical drives.

How a drive is physically installed will depend on the case.

Most drives are SATA (Serial ATA) which use simple, small cables for a
data connection. The ends of the cables are L shaped, just look
carefully at the cable ends and the connector on the drive and match
them up. Only one drive can be connected to each SATA port on the
motherboard.

Next install the SATA power cable. Some SATA drives also have a molex
power connector - make sure you connect **only one** of these ports to
the power supply, connecting both can damage the drive.

Newer SSD\'s will often use the PCI Express standard; for those, follow
the same instructions as you would do for a PCI Express graphics card.

### Other connections

!Some cables are attached to pins on a board (e.g. motherboard or
extension
card)"){width="300"}

In order to turn the computer on, you will need to connect the power
button and while you are at it, you might as well do the reset buttons
and front panel lights as well.

There will be a set of pins, usually near the front edge of the
motherboard to which you will attach the cables sometimes already
connected to the front of the case, or if needed to be supplied with the
motherboard. Most of the time the plugs will be labeled as the pins they
will connect to in the motherboard, there they can be difficult to read
since the print is very small or you may not be in the right orientation
to do so. The documentation that came with your case and motherboard
should tell where these connectors
are.

In addition, you can connect any case-specific ports if they are
supported by the motherboard. Many cases have front mounted USB ports
and audio jacks.

### Prepare for power up

Some people will put power to a system several times during assembly and
for experienced builders this may serve some purpose. For first timers
though, it's best to assemble a minimal complete system before powering
up. Minimal because that way there are comparatively few potential
sources of trouble, complete so that you can test everything at once and
because the fewer times you have to put power to an open machine, the
better..

If you've been working along with us you should now have such a minimal
system put together. Briefly this includes a case with a motherboard in
it, a processor (and its cooling unit) and some RAM plugged into the
motherboard, hard and floppy drives installed, and some kind of video
available. If your motherboard has built-in video, you might want to use
that for this first try, even if you are going to install a video card
later.

For this test, you'll want to have the computer open, so that you can
see all of the fans, and you'll need to connect a monitor and a keyboard
and a mouse (OK, you don't really need the mouse . . .)

!Comparison of VGA, DVI and
HDMI{width="180"}

Monitors will either have a VGA, DVI, HDMI (see picture, as they are a
lot less apparent than PS/2 / USB by comparison) or for newer ones, a
Thunderbolt 3/USB 3.1 plug. Most monitors use HDMI connectors, and so
most graphics cards have HDMI output. If you have one type of plug and
the graphics card has another, you can easily buy an adapter. Some cards
even come with one.

There are two standard connectors for mice and keyboards; PS/2
connectors and the more modern USB connectors. Plug the mouse and
keyboard in the appropriate slot.

Note: If you intend to install an operating system from a boot CD or
floppy, or modify BIOS settings you will need to use either a PS/2
keyboard, a USB to PS/2 converter, or a motherboard that supports USB
devices. Otherwise your keyboard will not work until the operating
system has loaded USB drivers.

Once you have this all set up, it's time to double check, then triple
check that you have made all the necessary connections and that you
haven't left any foreign objects (where's that screwdriver?) in the
case.

## Power up

Take a moment to check one more time that everything is as it should be
. On the first power up, you will be observing the computer itself to
confirm the cooling system is working correctly, making sure that your
fans work. The first thing to look for is that the CPU cooler fan spins
up, if it does not, cut the power immediately. This fan should start up
right away. If it does not, then something is wrong and you should
shutdown the computer immediately. When you are ready remove your wrist
strap, turn on the monitor, then press the power button, and observe the
inside of the open machine. (*Do not touch any part of the inside of the
machine while it is powered up*)

If the CPU fan spins up, check that all the other fans that should be
spinning -- case fans and fans on the power supply and video card (if
installed) are also spinning. Some of these fans may not spin up until a
temperature threshold is passed, check your documentation if anything is
not spinning.

If the fans spin, you can turn your attention to the monitor, what you
are hoping to see is the motherboard's splash-screen, usually featuring
the manufacturer's logo. If you see this, take a moment to bask in the
glow, you've built a computer!

If this happy event does not occur, if smoke appears, or if the computer
does not do anything, unplug the power cord immediately and check the
steps above to make sure you have not missed anything. Give special
attention to the cables and power connections. If the computer does
appear to come on, but, you hear beeps, listen carefully to the beeps,
turn the computer off, and refer to your motherboard\'s manual for the
meaning of the beeps. Some boards have an optional diagnostic device,
usually a collection of LEDs, which when properly plugged in will inform
you of the nature of the problem. Instructions for installing this as
well as the meaning of its display should be in the manual for the
motherboard. If the computer turns on but the only thing that comes on
is your power supply, turn it off. This probably means something is
shorted, and leaving it on could damage the parts.

If all is well it is time to turn the computer off, and close it up.
Then you may want to turn it on again and set certain options in the
computer\'s BIOS/UEFI (usually by pressing \'F1\' or \'Del\' a few
seconds after boot.) These options will be explained in the motherboard
manual. In general, the default options are OK, but you may wish to set
the computer\'s hardware clock to the correct time and date. The
BIOS/UEFI is also where you determine the default boot order of the
system, typically F\\floppy, then CD-ROM, then Hard Disc.

If you want a further quick test before you install an operating system,
you may find a bootable Disk or USB flashdrive such as
Knoppix extremely useful.

## Additional hardware and peripherals

Now that you have a working system it's time to think about installing
an operating system, which is covered in the next section. It's best to
leave the installation of additional components (like expansion cards,
and second video cards) and peripherals (printers, joysticks, etc.)
until after the OS install in order to allow the plug n' play features
of the OS to do their trick.

## References

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<references />
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