Computer Case
To start with, I will first look at the computer case. Modern computers always have ‘on circuits’. This essentially means that if the computer is plugged into power, there are a small number of circuits on the motherboard that are using this power. The internal clock will always be operating, and even when the power cable is disconnected a small battery will keep it running. Other small circuits will be operating that allow the computer to detect certain things. For example, a computer may wake up or start up when a key on the keyboard is pressed.
In order to do this, the computer must have enough power running through it to sense something has happened. This can include devices like network cards, so an administrator can start a computer up remotely. In this case, I will start by looking at the power button.
A single press of the power button will essentially trigger a start-up, shutdown, stand-by or hibernation. The power button is no longer a mechanical switch that controls electricity going to the computer, it is essentially a button that sends a signal to the motherboard. What effect this has can be configured by the operating system; it can even be configured to do nothing when pressed if you wish.
The problem with having a power button like this is, if the operating system were to crash, the power button would stop working. To get around this, if you hold the power button in for about three seconds, on some computers five seconds or more, this will power off the computer. This appears to have the same effect as switching off the computer. That is, everything in the computer will switch off including all the fans and the power supply. As before, there will be some power left to run the always on circuits, which can cause problems in some cases. Let’s have a look at when this may occur.
Hard Power Cycle
In some cases, you may need to perform a hard power cycle on the computer. This is basically the process of stopping all the power going to the computer for a short period of time and then reconnecting the power.
To understand this better, this computer is equipped with LED lighting on the motherboard, memory, and graphics card; this makes it easy to observe power flowing through the motherboard. You will notice that the fans are spinning and the LED lights are on. Notice the name on the graphics card, Windforce, is lit up as well indicating power is going to the graphics card.
On the front of the computer case there is a LED light indicating the computer is currently on. When I press the power button, after a few seconds the computer will go into stand-by mode. Notice that when it is in stand-by mode, the fans stop and the light on the graphics card goes out. However, the lights on the motherboard and memory are still on. The power light on the computer case may flash while the computer is in stand-by.
The state computer is in will determine which circuits are powered. While the computer is in stand-by, the memory in the computer will be powered as will some other devices to detect if the user wants to exit stand-by. For example, the user presses a key on the keyboard. The point to consider is, if the computer is shut down, there is stand-by power traveling through the computer. Particular devices that are able to wake the computer up even if the computer is completely shut down will still be using power.
I was once working on a computer that was completely shut down, but it still had power. I pulled the network card out of the computer and the computer without warning switched on. The power going to the network card was disrupted when the network card was pulled out, leading the computer to misinterpret this as a wake-up event and powering itself on.
The computer may not switch on like this if you pull out an expansion card. However, it illustrates how important it is to switch off the power before adding or removing hardware. If there is power traveling through the device or the slot you are plugging the hardware into, this can cause electricity to jump between the components and may cause damage to the device.
Thus, before adding or removing hardware, switch off the power and unplug the power cable. Not all motherboards, in fact most don’t, have LED lights letting you know the motherboard has power running through it. If you are not sure if the motherboard has power, unplug the power cable before you start working on it. If the computer is a laptop, you will need to remove the battery to ensure the computer is not powered. You can see the lights are now off in this computer and now it is safe to add and remove hardware. In some cases, the capacitors in the computer may take a little bit of time to drain. Some computers take longer than others.
The point to take away is that even when the computer is in stand-by or switched off, some circuits have no power while others will always have power. Knowing this, there are other times you may want to perform a hard power cycle. Sometimes, to fix certain hardware problems, you may need to perform a hard power cycle. Although when the computer first starts or resets itself, a signal should be sent to all the hardware to reset itself, if a component has a fault it may not respond. If all the components are not able to reset themselves it may cause the computer to lock up. A hard power cycle may fix this.
A common occurrence for this is when the computer has a black screen and won’t start. This generally happens more often with laptops then desktops. When this happens, make sure to disconnect the power cord from the computer, and let it sit idle to allow all power to drain. This removes the power from the computer, forcing chips in the computer that have failed to power down, effectively having the same effect as resetting them. Hopefully this does not happen to you with a laptop that has a battery that cannot be removed. If the problem is bad enough, you may need to let the laptop battery discharge in order to allow all the components in the laptop to discharge. Usually with no power, ten seconds should be enough time to allow all the components in the computer to fully discharge, but maybe longer for some computers.
Let’s have a look at an example of why it is important to unplug everything before performing maintenance on a computer.
Example Circuits with Power
Let’s consider an example motherboard. You can see that with this motherboard both power connectors are not plugged in, in fact nothing is plugged into this motherboard. Let’s now watch what happens when I plug an HDMI cable into the video card. You will notice that the CPU fan starts spinning. It is not a magic trick, plugging a HDMI cable into the video card provided power to spin the CPU fan.
There is one little piece of information that I have not told you. In this case, the HDMI connector I plugged in is connected to an output HDMI device rather than an input HDMI device like a monitor. Thus, an HDMI signal is traveling to the computer which is providing a small amount of power to the computer.
Although I have incorrectly used an HDMI cable to demonstrate this point, it shows that power can sometimes come from unexpected places. Keep in mind that one of the reasons you are there fixing a computer is because something has gone wrong. This is why you should unplug everything before you start doing maintenance inside a computer. In the real world, let’s face it, everyone takes shortcuts, so at least unplugging or switching off the power is a good start.
Reset Button
Your computer may have a reset button on the computer case. Shown here are three different computer cases. The power button will generally be a large button on the computer case, often circular in shape but it does not have to be.
The reset button will generally be a small button. It is done this way to make it harder to press by accident. On some computer cases, it may be located in a recess in the computer to make it harder to press. On some computers you may need to use a paperclip or something similar to press the reset button.
The reset button performs a hard reset of the computer. The function of the reset button can’t be changed like the power button. It will always reset the computer. A hard reset will mean the computer will reset and go back to the POST screen. Post means Power-on self-test. So, the computer will essentially perform the same checks that it did when it first starts up. A reset does not cut the power to the electronics, it just tells everything to reset itself.
A hard reset is different to a soft reset, such as pressing ctrl-alt-delete or selecting restart in the operating system. If you use either of these methods, the computer will not perform POST checks; however, many do some quick checks before starting up. Not all computers will include a reset button. Many laptops do not have a reset button. In some cases, the laptop may have a reset button, but to press it you will need something to press it with, like a screwdriver. If the laptop does have a reset button, and they are not that common, it will most likely be on the base of the laptop.
Let’s have a look at what effect the reset button has on a computer. The OS on this computer is currently running software. On the motherboard are two pins to which the reset switch is connected. Notice that when I press the reset button, the computer, without notice, immediately restarts. Unlike a soft reset, you don’t get any chance to save anything and any unsaved data will be lost.
A reset won’t cut power to the computer like switching the computer off will, so generally if I need to perform a hard reset of the computer, I don’t use the reset button, I will instead hold the power button down until the computer switches off. Then I will give it a few seconds and switch it back on. It is a little slower this way; however, you get a better result than the reset button, since it includes power cycling components of the computer rather than just resetting them. Given that holding down the power button and switching the computer back on has become a reliable way to effectively restart the computer, the reset button does not get used as much as it did.
Front IO Panel
On the computer case there will generally be a number of standard connectors. A lot of the time these are found on the front of the computer, and this is called the Front IO Panel. In the motherboard manual, most of these connections go to the same place and are referred to as the front panel connectors. In a later video I will look into these connections in a lot more detail.
Most computer cases have the same connections on the front, but it is possible for the manufacturer to include fewer or more connectors if they wish. These, however, are the standard ones that you will most likely come across on almost all computer cases.
The reset and power buttons I have already covered, so I won’t worry about going through them again. When I press the power button, notice that the power light goes on. The power light will be solid when on, when in stand-by they generally will flash and when off, well the computer is off!
Under this light is the Hard Disk Light. The hard disk light, otherwise known as the hard drive activity LED, traditionally flashed when the hard disk was accessed. Nowadays, Solid-State Drives are also commonly used. If the storage is connected internally, such as via a SATA connector on the motherboard or an M.2 slot, the hard disk light will blink whenever the storage device is accessed. However, if the storage is connected externally, such as via USB or an expansion card, the hard disk light will remain inactive when the storage is accessed.
These are the standard connectors provided by the motherboard. The next connectors I will look at are the audio connectors which you will find, nowadays, pretty much supported on all motherboards. These will generally be the speakers and microphone input. To use them, it is just a simple matter of plugging them in.
If these connections are present, which they usually are, you will typically find two. If you need more sound options, you can usually find additional jacks at the back of the computer. For instance, if you want to use surround sound, you will need more than a single speaker connector.
Lastly, other common connectors you will find on the front of the computer will be USB connectors. In the case of this computer, there are dust caps in the USB connectors that need to be removed before they can be used. Different computer cases will have different numbers of USB connectors, some more than others. It is fairly common for there to be at least one USB 2 connector and one USB 3 connector. The USB 2 connector is generally black and the USB 3 connector is generally blue.
This covers the basic connectors on the front of the computer. Let’s now have a look at what else is generally found on the front of a computer case.
Computer Drive Bays
On the front of the computer, you also may have some accessible drive bays. I say maybe, because most computer cases currently on the market do not have any drive bays accessible from the front of the computer. On this computer, there are two 5¼ inch drive bays and two 3½ inch drive bays.
The 5¼ inch drive bay is mostly used for optical drives; however, there are some other devices that use them, for example, for removable drive bays, SD card readers and digital displays. Digital displays allow you to monitor things on your computer such as CPU temperature and fan speeds.
With optical drives becoming less common on computers, accessible 5¼ inch drive bays are becoming rare on computer cases.
I will now have a closer look at the 5¼ inch drive bay. This computer has an optical drive installed, so I will have a look at how to remove it. Different computer cases will have different ways of performing maintenance on them. In this particular computer case, there is a slide at the back that, when pushed back, the side of the computer case opens. Once it is open, the side of the case can be removed.
For this computer case, two covers need to be removed before I can remove the optical drive. To do this, there is a blue slider I need to push to unlock the front case plate, and it can then be removed. There is another plastic cover that needs to be removed before I can get to the optical drive. Notice that it is locked into place. Before I can remove it, it needs to be unlocked.
This computer case has a locking mechanism that holds it in place, and for some computer cases, you will need to use a screwdriver to lever the clips so you can remove them. In this case, the locking mechanism is blue in color. When I have a closer look at it, notice there is a down arrow on it. Often computer cases will have some clues on how to perform maintenance on them. Look for arrows, numbers and for this computer, any plastic that is blue in color is some kind of lever or slide used to unlock something.
When I press down on the locking mechanism, notice that the plastic cover comes off easily. If you are not sure how to service the computer, have a look through the manual, because often if something is difficult to remove, there may be a trick to getting it out easily.
Before I remove the optical drive, I first need to unplug the SATA and power cable going into the optical drive. The optical drive can now be removed.
A locking mechanism also holds the optical drive in place. To remove the optical drive, push down on the locking mechanism and the optical drive can be pulled out. The optical drive has now been removed.
The 3½ inch drive bay is essentially a smaller version of the 5¼ inch drive bay. Traditionally, used for floppy disk drives. Floppy disk drives are long obsolete, thus externally accessible 3½ inch drives are even rarer on computers cases than the 5¼ inch drive bay. If you have a 3½ inch drive bay and you choose to use it, you will probably use it for an SD card reader or similar device. In the case of this example, the 3½ inch front panel adds three additional USB ports and some SD card reader slots. Don’t worry if you don’t have a 3½ inch drive bay; if you wish to add additional front panel connectors there are plenty of 5¼ inch front panel connectors you can purchase. If you don’t have any drive bays at all, you can also use an external USB hub. Many USB hubs on the market come with SD card readers, additional ports and even video connections.
Now that we have had a look at drive bays, I will next have a look at how the vents in the computer are used to keep the computer cool.
Vents
ATX computer cases are designed so the air flows from the front of the computer case to the back of the computer case. I have used an empty computer case so we can understand the concept better.
At the front of the case, there will be some intake vents. In this computer case, you can see there are a lot of holes at the front of the case where air can flow in. It is important that these vents are not blocked and are free of dust. If the computer has no vents on the front of the case, the vents are most likely on the side of the case. The vents will always be towards the front of the case somewhere; regardless of where they are, make sure that they are not blocked and are free of dust. If the vents get blocked with dust, this will affect the ability for the computer to get good airflow. Most likely the fans in the computer will have to work harder and the computer may become hotter.
Once the air is in the case, it needs to go somewhere. Without any extra fans, most of the air will exit out the Power Supply Unit. Computers are not sealed units, thus some air will always enter and escape through anywhere there is a gap in the computer case. This is the simplest case of air flow for a computer and without additional cooling devices in the computer, the airflow will follow this pattern. The main point to take away is, air is dragged from the front of the computer case across the motherboard and exits via the power supply. Since hot air rises, the power supply is often found at the top of the computer case, but not always.
Now that we understand how the air flow works, let’s look at what can affect air flow.
Poor Airflow
In this example, this computer has a missing blanking panel, side panel, blanking plates and poor cabling. All of these contribute to poor air flow inside the computer. At the front of the computer, notice that the blanking panel is missing. If I were to take a guess, I would say that an optical drive was installed at some stage. When the optical drive was installed the blanking panel was removed, however, when the optical drive was taken out the blanking plate was not replaced.
Some computer cases come with filters, and if you have a missing blanking panel like this, the air won’t come through the filter. Also, if the motherboard is at the bottom of the computer case, having a missing blanking panel at the top will mean the air will flow through the computer case from the top rather than the bottom. The air won’t then travel over the motherboard which effects the cooling of the components on the motherboard.
The side panel is missing, essentially completely disrupting the air flow. When building the computer or performing maintenance, it is fine to remove the side panel and use the computer for short periods of time. However, once you have completed the work, you should replace the side panel.
At the back of the computer, the IO shield is missing and also the blanking plates. You can see that there are holes at the back of the computer case and thus not a perfect seal. Having more holes prevents the air flowing the way it was intended to and allows more dust into the computer.
When I look inside the computer, you can see how much dust gets in. Over time, even a well-designed computer will get dust in it. So, you can’t really prevent it; however, you can reduce the amount of dust that does get inside. If you get too much dust inside the computer, this can prevent the fans spinning. If your computer is configured correctly, it will alert you if the fan has stopped; otherwise, you won’t know and the computer will start heating up. When the computer starts getting hot, it will automatically throttle down, reducing its performance to prevent it overheating. This can lead to decreased performance over time and accelerated wear-and-tear. If the system overheats, it can shut down without warning.
In the case of this computer, notice the amount of dust built up in the bottom of the computer. This dust won’t affect air flow, but when you see this much dust, it is more than likely to have got into other areas. You can see, in this computer, the dust has got in-between the blades of the heat sync of the CPU fan. This will reduce the efficiency of the heat sync and the fan.
Lastly, you can see the cabling is a mess. Poor cabling management like this blocks the air flow, and cabling can get stuck in a fan stopping it. Computer cases will often be designed with cabling in mind. If the computer case does not have cable management features, cable tie the cables so they are out of the way.
The next consideration is how much airflow you have in your computer case.
Additional Fans
If you want to improve the air flow in your computer, one option you have is to add additional fans. There are two different types of fans available, high airflow and static pressure. Looking at the fans, you won’t see much difference between them other than the blades used in the fans. The blades affect how the air travels through them.
High airflow allows more air to flow through; however, the air is spread out. These fans are good for case and exhaust fans since you want to get a lot of air out. You can also use them as case intake fans since you want to get air into the computer.
Static pressure fans have less air flow, but the air flow is concentrated. These fans are good for radiators and intake fans. You will also find them on heat syncs. Static pressure fans, although having less air flow, put more force behind the air. This makes them good to get air through material that may provide resistance, for example, heat syncs and filters. Thus, even though you could use a high airflow fan for an intake fan, if the computer case has filters, you are best using a static pressure fan. Also, the front of the case generally has more obstructions than the back, so static pressure fans generally work better in this case.
To make things more complicated, some fan manufacturers have hybrid fans which are a cross between the two. When using these fans, you can use them as high airflow and static pressure fans.
Now let’s have a look at where you would place these fans.
Rear Case Fans (Exhaust Fan)
The first fan that I will look at is the rear case fan. This fan is found at the back of the computer case. When you purchase a computer case, most times it won’t include this fan and you will need to add it.
Fans are not keyed, thus you can install them the wrong way. In the case of this fan, it is an exhaust fan and if you install it incorrectly, it will push air into the computer case rather than removing it. To determine which way the fan needs to be installed, most computer fans will have some arrows on them indicating the direction the fan spins in and the direction the air will travel through the fan.
The up or down arrow indicates which way the fan is spinning. The left or right arrow indicates which way the air flows through the fan. Let’s have a look how to install the fan.
In this example, I am going to install an 80mm high air flow fan. Fans come in a number of different sizes, it is just a matter of getting the right size for your computer.
When I have a look at the fan, notice the arrows on the side of it. If your fan does not have these arrows, you can always test it to see which way the air goes through it. In the case of this fan, it is powered using a Molex connector. So, I will plug the Molex connector into the power supply.
To make it easier to follow along with the installation process, this computer case does not have a motherboard installed, which makes it easier to see what is happening. For this reason, to start the computer and power the fan, I will use an ATX jumper switch. This switch effectively shorts the two pins in the ATX connector which triggers the computer to start up. Now, all I need to do is switch on the power switch.
To test the air flow of the fan, move a piece of paper slowly towards the fan making sure you stay far enough away that it does not get sucked into the fan. If you find you are not getting a result, try the other side. Air flow tends to be more noticeable on the exhaust side than the intake side.
Before I install the fan, I will exercise good maintenance practice and unplug the computer. In IT you will probably find that you take a lot of short cuts here and there, but if you are working on a customer’s site, it is always a good idea to exercise good practice, otherwise it looks unprofessional.
I will next place the fan in the case, making sure that I check it is oriented the correct way. Since it is an exhaust fan, it needs to blow air out of the computer case.
Next, I need to line the screw holes up. In this computer case, two different size fans are supported, thus there are two different sets of screw holes. This computer case has a lot of holes in the back of the case for ventilation. In this instance, I just need to locate the only holes that are round. To locate them, you just need to look around carefully as they can be hard to see.
Lastly, I need to screw in the four screws to hold the fan in place. I will usually put two diagonal screws in place first and half screw them in. This will hold the fan in place while I put the other screws in.
Once all the screws are in place, I can plug the power back into the computer and switch it on to complete a final test. You should be able to observe that the fan is operating as an exhaust fan, as intended.
When installing fans, make sure you are installing the fan in the correct orientation and using the right type of fan. Let’s now have a closer look at how the computer connects to external devices.
I/O Area/Panel (Aperture)
In the ATX standard there is an area dedicated for Input/Output. The official name is the I/O Aperture but pretty much nobody will refer to it by that name. If they do refer to it, it will probably be called I/O Area or I/O Panel. Any ATX motherboard is designed to be compatible with any ATX computer case; however, proprietary computers may have an I/O area that differs from the ATX standard. The ATX standard requires the I/O area to be a particular size, but proprietary motherboards can be of any size.
Under the ATX standard, the I/O Area is an empty canvas for manufacturers to customize as they desire, with no restrictions on where ports and connectors are put or what ports and connectors are used.
In order to prevent dust, dirt and help prevent electromagnetic interference, it is important to use the manufacturer-provided metal I/O shield. Since the manufacturer can customize what goes in this area, they also need to provide a customized I/O shield. It is important you use the I/O shield that came with the motherboard because even small changes in the connections in the I/O Area will cause the I/O shield not to fit correctly.
On some motherboards, you will find the motherboard does not have an I/O Shield. In this case, the motherboard completely fills the I/O area and an I/O shield is not required. So don’t be alarmed if you don’t find an I/O shield with your motherboard, as it may not be required.
Now that we understand where connectors may be found, let’s have a look at what you may expect to find.
Connectors/Plugs/Jacks/Ports/etc.
Let’s go through some terminology on how devices are connected to your computer. To make things simple, everything is essentially a connector. So, if you can’t remember, call it a connector since this is technically correct.
First, there are plugs. These essentially plug into something else. The something else is generally either a port or a jack. Jacks are usually referring to the 3.5mm connectors for audio. Ports are generally referring to everything else.
With newer technology, you will generally find these are all simply called connectors. In the old days, the cables tended to mainly pass data in one direction and there was a pretty clear host to device relationship. That is, the computer was the host and what was connected was the device. Nowadays, it is not a clear relationship like that. For example, a video signal is typically exported from the computer to a monitor. However, if you have a video capture card, you would plug a video cable into the computer and it would capture the video signal rather than transmit it. Thus, the direction that data is traveling has changed. So, is the computer with the video capture card now the host? Is the device transmitting the host? The answer is, it depends on your perspective. Now add devices like USB hubs and mobile devices, which can act as a host or a device. There are also video cables that can send audio in the reverse direction to the video.
When you say I am plugging this into the computer, it generally assumes the computer is the host, which nowadays may not be true or maybe partly true. Connectors cover the other end being either a host or a device, so you can see why the trend for new connections is to simply call them connectors, because connectors are technically always correct, regardless what you are connecting to the computer. There is no assumption about which way the data is traveling or which end is acting as the host.
Connectors also cover headers. Headers are found on the motherboard. These are square arrangements of two lines of pins which may have a shroud around them, which is a black plastic container around the pins. These headers are keyed with a missing pin to prevent the wrong connector being plugged into them.
Connectors also refer to the CPU sockets and expansion slots. Essentially, everything in the computer that allows you to connect something is some kind of connector. Now that we have a better understanding of how the I/O area works, let’s have a closer look at some of the connectors that you may find there.
Connectors
Shown here I have three different I/O Areas. You can see just from these examples there are a lot of differences in where the connections are placed and what connections are included. I will now go through the common connections you will come across. It is important to be able to recognize them.
The first connections I will look at are the video connections. One of the more common connections found on computers is DisplayPort. DisplayPort is quite commonly used on monitors and other devices. If you decided to use a TV set as your monitor, not all TV sets will have a DisplayPort. TV sets generally use HDMI rather than DisplayPort. HDMI is quite common in home entertainment systems, which is why your TV probably supports it, but it may not have DisplayPort. Monitors are more likely to have DisplayPort but that is not always the case.
In the old days, there were a lot of differences in the features of DisplayPort and HDMI. Nowadays, feature wise there is not much difference between the two, although those features may be implemented differently. The main difference between the two is that DisplayPort does not support a feature called ARC. ARC allows for audio to travel in the reverse direction to the video. This is important if you want to use audio equipment which may not be plugged into the device that is transmitting the video. This is not that important with DisplayPort, as it is generally used with computers and, in this case, you would plug your audio equipment directly into the computer.
The next video connection you may come across is DVI. DVI is considered obsolete nowadays, so your computer may not have it. Unless you have a need to use it, I would not use it. Either use DisplayPort or HDMI.
Next you may have a PS/2 port. In the old days this was two ports, one for the mouse and one for the keyboard, then later this was reduced to one port. Although there is only one port, you can get splitters which will divide the port. Also, if your computer does not have a PS/2 port, you can purchase PS/2 to USB adapters.
Although PS/2 ports are considered obsolete by today’s standards, you may find a small collection of competitive gamers that still use them. This is due to the way the protocol is designed; PS/2 may give you a slightly quicker response time, however, other competitive gamers state this time is so small that other considerations like the type of mouse and keyboard used make a much more noticeable difference.
PS/2 does not support hot swapping, thus if you unplug or plug it in, you may need to restart the computer. PS/2 also supported more keys being pressed on the keyboard at once, although newer USB keyboards can now also support more keys being pressed on the keyboard. The problem you may come across is newer USB keyboards may not work with the BIOS on older computers. This should not be a problem with newer computers. To get around this, some keyboards have a switch to change compatibility mode. I got around this issue by simply purchasing the cheapest USB keyboard I could find with the least amount of features. I leave this in my kit bag and when I come across a BIOS that won’t support a newer keyboard, I simply use this keyboard to access the BIOS and unplug it when I am done. Since it is only a BIOS related problem, once the computer boots, the newer keyboards should work fine.
In the real world, I would personally not be using PS/2 anymore, just use USB. If you come across an old computer that won’t let you into the BIOS at start up, have that cheap keyboard ready to use. If you have an old keyboard that works with old BIOS’s, don’t throw it away as you may need it one day.
The next connections I will look at are the audio jacks. The audio jacks are generally color coded so you know which is which. If you have surround sound 7.1, you will have six jacks. If you have surround sound 5.1, you will have five jacks. If you only have stereo sound, you will generally have three or less. Although stereo sound only requires one jack, computers will generally also have a mic in and a line in.
If you are just plugging a single set of speakers or headphones in, use the black jack. On some computers, the jack will auto sense what has been plugged in and change accordingly. When this is the case, you will generally have a Window appearing asking you to confirm what was just plugged in.
It has become less common, but your computer may also have an optical fiber connection. These are becoming less common with the increased use of Bluetooth. These one-way connections make them less user-friendly as they cannot send any data back to the computer, meaning they can’t send any configuration information. For example, the device telling the computer what audio formats it supports or what audio frequency. To get the best results, you may need to change some settings in the computer. Also, since optical is one directional, the computer won’t know if the audio device is working. The only real way you will know it is working is if you hear sound coming out of it.
Next there is the RJ-45 connector which is your network port. Although most are not labeled, it is pretty common for new computers to have a one gigabit network port.
On some computers you may have Wi-Fi. In this example there is a connector you can screw antennas into. Different antennas will give different results. So, if your Wi-Fi is poor, it may be worth changing the antennas. In some cases, the computer won’t have Wi-Fi installed and it will simply have an area to add the antennas if you decide to use Wi-Fi later. Not all I/O areas will have this, even if the computer allows Wi-Fi to be added later on.
You will pretty much find that all computers on the market will have USB. The ports are color coded to make it easier to determine which is which. Black ports are USB 2. These are low-speed ports so you would plug your keyboards, mice and slow USB flash memory into these ports.
USB 3 ports are generally blue in color. Plug your high-speed devices into these ports, such as fast USB flash drives, external storage devices and devices that need a lot of speed like video capture. If you are not sure, for example if you have a USB flash drive and don’t know what it supports, the ports are backward compatible, so you can plug it into the port. The problem you will have is, you may start running out of high-speed ports. For this reason, I make sure my keyboard and mouse go into a USB 2 port and if I am not sure everything else goes into a USB 3 port if they are available.
When USB 3.1 first came out, some manufacturers made these ports red. This was to make them different to the USB 3 ports. However, as time went on, some motherboards upgraded all their ports to USB 3.1 and thus the manufacturers just decided to make these ports blue. Thus, sometimes you may find these ports are red and other times they may be blue. It really depends on what the manufacturer decided to do.
To make things more complicated, there is also USB 3.2. These ports are often a light blue. However, if the motherboard only supports USB 3.2, don’t be surprised if they made all the ports blue like USB 3. I can only assume they do this to make things simple, since USB 3 is often associated with blue and USB 3.1 and 3.2 support USB 3, so why not make them blue. Having only black and blue ports is easier than having a lot of different colors.
In the real world, I generally find that the ports are either black or blue. These tend to be the colors that are used nowadays. If you see different colors, even a lighter shade of blue, it is most likely this port supports a higher speed. The manufacturer has made them different colors so you can tell them apart. So, black for all your low-speed devices. Blue for your high-speed devices. And different colors are generally used for your very high-speed devices. Thus, only use these when you have a device that supports it, which will be for very fast storage devices, video capture devices or high resolutions such as 4k.
Next there is the USB Type-C connection. These are a little more complicated because they are generally not color coded. However, there is one general assumption you can make, which the market seems to be following, and that is, these are the fastest USB connection your computer supports. Motherboards don’t tend to come with many of these connections, well not yet anyway, so try and use them in devices that require very high speed.
The last USB I will look at is yellow in color. You don’t tend to see these very often. These connections are essentially always on, thus if you want to charge your mobile device when the computer is off, plug them into this type of connection. The problem with these connections is that, like the Type-C connection, you can’t tell what speed it supports. Thus, it could support any speed. With USB chargers becoming more common place, for example, adding them to power points and power strips, to me it seems there is not much demand for them given the number of alternatives available. Most people probably only charge their phone using the computer when they are sitting in front of it, and this is probably the reason we don’t see them being used that much.
Sometimes USB ports will have additional power output which is good for charging mobile devices. In some cases, the manufacturer may make these ports a different color to add to the confusion. In short then, black for USB 2, blue for USB 3 and light blue for USB 3.2. If you see any other color, it is the manufacturer trying to tell you that there is something different about that USB port, either the speed is different, the power output is different or it is always on. Thankfully it looks like we are starting to move towards only using black, blue and light blue.
Let’s next have a look at the next part of the computer case that allows for external connections and some customization.
Expansion Area
Located on the computer case, generally at the back, will be an area for expansion cards. Regardless of what slot types inside the computer are being used, the spacing between expansion cards is always the same. Spacing is the width of the expansion cards. The expansion cards are required to be a minimum width but can also be a multiple of that width, for example, double width. As long as the expansion card is a multiple of the spacer size, it meets the standard.
ATX supports up to seven expansion slots. This does not mean that it needs to use them all. In this example computer case, all seven expansion slots are being used. In the second example, only five expansion slots are being used. Keep this in mind when purchasing a computer case. If you purchase a full-sized motherboard, you will need a computer case with seven expansion slots. The smaller motherboards can be used in smaller computer cases.
Other standards may support more expansion slots, but the size of the spacers is always the same. Other standards that support more expansions slots, often proprietary standards, you won’t generally find on consumer products; you generally only find them used in specialized products often found in server rooms.
If you are using a computer that uses a proprietary motherboard, these computer cases still use the same spacing size for expansion cards since all expansion cards are made to this standard.
End Screen
That concludes this video on some of the basic components that make up a computer system. In other videos I will look at other components that make up a computer system. Until those videos, I would like to thank you for watching.
References
“The Official CompTIA A+ Core Study Guide (Exam 220-1101)” pages 14 to 17
“Reset Button” https://en.wikipedia.org/wiki/Reset_button
“Difference between Plug, Port, Jack and Connector” https://www.youtube.com/watch?v=s3GPU8lVkRo
“Cat Video” https://pixabay.com/videos/cute-cat-funny-cat-kitten-domestic-3092/
“Picture: PS/2 port” https://en.wikipedia.org/wiki/PS/2_port#/media/File:PS2_keyboard_and_mouse_jacks.jpg
“Picture: Shrouded header” https://en.wikipedia.org/wiki/Pin_header#/media/File:Stiftwanne2x13v2.jpg
“Picture: CPU socket” https://en.wikipedia.org/wiki/CPU_socket#/media/File:Socket_AM2.jpg
“Picture: PCI Express” https://en.wikipedia.org/wiki/PCI_Express#/media/File:PCIe_J1900_SoC_ITX_Mainboard_IMG_1820.JPG
“Picture: USB to PS/2” https://upload.wikimedia.org/wikipedia/commons/6/63/Usb_to_ps_2_adapter_IMGP1414.jpg
Credits
Trainer: Austin Mason http://ITFreeTraining.com
Voice Talent: HP Lewis http://hplewis.com
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