Introduction
An output device is something that takes a signal from the computer
and makes it into something that makes sense to you. All computers
think in billions of 1s and 0s which makes no sense to you when
you to simply see or hear them.
Many output devices use a digital-to-analog conversion, which
involves converting billions of 1s and 0s into sights and sounds,
which are interpreted by your senses.
In this module we discuss three kinds of output devices:
Display Adapters
We are going to discuss the display adapter and some of its basic
functions. All of the intricacies of a display adapter are not going
to be covered due to the fact that we do not need to know everything
about the display adapter in other to troubleshoot it.
Monitors
The monitor is the main device that you use for any sort of display.
We will be discussing the basic functions of a monitor so we can
know when it is defective and how to troubleshoot it appropriately.
Sound Cards
Almost all users will use sound for one reason or another. The most
common reasons are for music and for games. All eMachines sound
cards are built into the motherboard. We are going to be discussing
the basic function so that we are better able to troubleshoot the
sound card.
Display Adapters
Your display adapter has the job of taking complex video
instructions from many different types of applications and
converting it into an image that you can understand. Because there
is so much to keep track of, sometimes your display adapter needs to
have memory. The more memory you have, the higher resolutions,
faster refresh rates, and smoother rendering you can achieve. This
is especially important for DVD movies and gaming.
Shared Memory vs. Dedicated Memory
Shared memory means the card uses motherboard memory. Dedicated
memory means that the card has its own memory, which is built right
into the card. There are different advantages to each configuration.
Imagine you are sitting at a desk with a cabinet within arms reach.
Now imagine sitting at a desk where reaching into a cabinet means
having to get up and walk across the room. It is easy to see which
setting is more convenient. Having a cabinet within arms reach is
like having dedicated memory.
On-Board Video vs. AGP Display Adapter
Short for Accelerated Graphics Port, a bus on the motherboard
designed specifically for the display adapter. AGP introduces a
dedicated channel so that the display adapter can directly access
motherboard memory more efficiently. AGP is also designed
specifically for the throughput demands of 3-D graphics. AGP offers
various levels of throughput: 1X (266 MBps), 2X (533 MBps), 4X (1.07
GBps), and 8x (2.1 GBps).
Sometimes system specifications will advertise an AGP accelerated
onboard graphics adapter. This means not only is the display adapter
part of the motherboard but it also runs at the speed of AGP.
eMachines has systems which have an onboard display adapter and an
AGP slot so you have the option to upgrade at a later time.
Installing 3rd Party Display Adapters
Due to support limitations, eMachines only offers the most basic
instructions for upgrading to a 3rd party display adapter.
In most cases, plugging a display adapter into the motherboard is
not enough to disable the onboard video. You should walk the
customer through disabling the onboard display adapter by suggesting
the following steps to the customer, however you cannot walk them
through the installation of the 3rd party display adapter.
Here is the best method for installing a third-party display
adapter:
Remove the 3rd party display adapter (if it is already installed)
Disable the onboard video driver in Windows (do not uninstall it)
Shut down the computer
Now install the3rd party display adapter on the motherboard
Plug the monitor into the 3rd party display adapter
Turn on the computer
Install the 3rd party display adapter drivers
Refer them to the manufacturer or Priority One for any additional
support
Display Settings
There is an icon in Control Panel that allows you to change settings
regarding the screen area and color depth.
The screen area is defined as the number of pixels on the screen.
For example, a screen area of 1024x768 means it is 1024 pixels wide
by 768 pixels tall. Typical computer monitors are 4:3. Some
monitors, including our Notebook LCD display, are 16:9. Monitors
display pictures by dividing the display screen into thousands (or
millions) of pixels, arranged in rows and columns. These pixels are
so close together that they appear to be a solid image to the human
eye. A higher screen area will result in a smaller, sharper picture.
While a lower screen area will result in a larger, blockier picture.
Color depth refers to the number of unique colors that are displayed
on the screen at once. Imagine having a choice of only 3 colors and
not being able to mix them. How real could you make anything look?
Now imagine having a color choice of 16 million or more. Low color
settings will make the screen look washed out and less vibrant.
Follow the instructions below to modify display settings:
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Click on START
Click on Control Panel
Switch to Classic View (if necessary)
Double-click on the Display icon
Click on the Settings tab
Now you may adjust the screen area and color settings
Click on OK when you are finished |
Note: Windows XP prefers 800x600 screen area and 16-bit color depth
by default.
User-Specific Settings vs. System-Wide Settings
Whenever you make changes to the computer, some settings are
user-specific and some settings are system-wide. Changing an option
such as the background is usually a user-specific setting, while
other changes such as color depth and screen area are system-wide.
When creating a new user account on the system, all of the settings
that are imported by default (shortcuts, desktop wallpaper, sounds,
etc.) are system-wide settings. Any settings that are not imported
by default are user-specific settings.
For example, flipping the display upside-down and gamma settings are
often times system-wide. Many games make system wide changes to the
display when playing and if that game should crash and not undo
those changes often times it will create unwanted results for every
user account on the computer.
Monitors
Cathode Ray Tube (CRT) Monitors
This type of monitor uses magnets and an electron gun as its means
of projection. There is an electron gun that shoots electrons from
the back of the monitor to the front and magnets are used to evenly
space those electrons across the back of the screen. When you put a
magnet near the front of the monitor it can permanently damage it
because it draws more electrons than it should to one point on the
monitor.
Cleaning a CRT Monitor
Cleaning a monitor is very simple and easy. Spray a small amount of
ordinary glass cleaner on a paper towel in order to wash the glass
on the front of the monitor. Be careful not to let anything drip
down inside the monitor.
Liquid Crystal Display (LCD) Monitors
Extreme cold or heat will cause the liquid inside the LCD display to
expand/contract. If left out in the freezing cold range the liquid
can freeze and burst ruining the display. Imagine a strain of DNA
and how it wraps around each other in a double helix. The crystals
that are used in an LCD display look very much the same as a strand
of DNA. Depending on how much electricity that a crystal receives
then it unwinds and winds accordingly changing the color of light
that is seen.
Cleaning an LCD Monitor
An LCD display is drastically different in how you clean is versus
how you can clean a CRT. A CRT monitor has a glass panel that can
handle somewhat abrasive chemicals. LCDs are almost always plastic
and as such glass cleaners will damage the surface of the monitor.
The best thing to do is just use a damp cloth with some water and
wash the screen.
Monitors Use an SVGA Connector
A standard eMachines monitor uses a regular 15-pin SVGA cable. One
thing important about the 15-pin connection is that rarely are all
15-pins needed. Most monitors only have 14 or 13 pins and rarely is
15-pins seen.
Each pin corresponds to a different function of the monitor. If the
cable is only partially plugged in you can get anything from wrong
colors to a scrolling display.
On-Screen Display (OSD) Options
The On Screen Display allows you to make changes to your monitor
settings such as vertical, horizontal, pincushion, contrast, and
etc. The following is a list of the generic options that almost all
CRTs have:
Contrast: Adjusts the luminosity level of
the display
Brightness: Adjust the black level of the
display
H-Position: Used to center the image to
preference horizontally (side to side)
H-Size: Used to adjust the size of the image
horizontally to preference (side to side)
V-Position: Used to center the image to
preference vertically (top to bottom)
V-Size: Used to adjust the size of the image
vertically to preference (top to bottom)
Pincushion: Used to straighten the sides of
the image by pulling them in opposite directions
Trapezoid: Used to even the widths of the
top and bottom of the display (pulling the sides in opposite
directions)
Parallelogram: Use to center the top and
bottom of the display (pulling the sides in corresponding
directions)
Rotation: Use to rotate the image until
sides of the image are parallel to the edge of the bezel
Zoom: Used to Zoom IN/OUT of the image on
the screen
Degauss: Used to resolve issues with the
display when it becomes discolored or washed out in appearance
(often times used when magnet is put to the screen)
Recall: Resets the display settings to the
original factory reset values
Note: Notebook displays are not controlled by OSD settings. They are
controlled by software and keyboard shortcuts.
Sound Cards
A sound card takes a digital signal 1s and 0s and turns it into an
analog format or a sound wave. All sound is comprised of simple
vibrations. Sound cards are made to do this simple conversion also
it specializes is taking in sounds from the outside world and turn
them into 1s and 0s as well.
Codecs
Short for compressor/decompressor, a codec is any method for
compressing and decompressing data. Codecs can be implemented in
software, hardware, or a combination of both. A popular codec is
MPEG1 Layer 3 (mp3).
Codecs are needed because there is limited information that a
computer can keep track of. For example, the MPEG Layer 3 codec is
popular because it compresses files by omitting sounds that the
human ear cannot hear. Have you ever felt that music when listened
to in MP3 format sounds more flat then say a live band or
orchestra? Codecs take shortcuts allowing you to compress the data
and fit more information on your hard drive.
With regard to audio, if you do not have the proper codecs installed
you may not be able to hear sounds while watching certain videos or
listening to certain songs that require them.
Ports of a Sound Card
All the sound card ports both on the front and on the back are color
coded with a setup guide and whatever speakers came with the system.
There should be no reason for a customer to be able to get them
confused and plug them into the wrong port but it has and will
happen in the future. Depending on the system there are 2 on the
front and 3 on the back. There is a microphone and headphone on the
front and a speaker, line-in, and microphone on the back.
Amplified vs. Non-Amplified
Amplified speakers ship with a power adapter and a volume control
button. Non-amplified speakers do not have a volume control and draw
their power from the sound card.
A line-out port requires amplified speakers. A speaker port does
not. Think of it like this:
A lion would be a speaker port
A mouse would be a line-out port
Does a lion need a megaphone in order to be heard? Does a mouse need
a microphone to be heard? Amplified speakers would be using a
megaphone. Could the lion use a megaphone? Yes, they could and it
wouldnt cause any problems.
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