Build a Mini-ITX Computer
Desktop Training - DSL

Project: Build a Mini-ITX Computer

This project goal is to build a small computer using the mini-ITX format. The mini-ITX mainboard provides a extremely small, integrated and flexible x86 platform to the home or business user. The choice is this example is a Eden fanless computer that basically creates no sound.

The mainboard provides onboard integrated graphics, audio,TV-Out support, 10/100 LAN, primary and secondary controllers and an additional PCI slot for expansion.. As you can see in the picture PS2 mouse and keyboard maybe attached so this will function as a desktop computer or it can provide the basis for an appliance / server.


The mainboard measures only 170mm x 170mm making it 30% smaller that most other ATX platforms. The VIA Apollo PLE133 North Bridge allows for 2D/3D acceleration and supports Soundblaster Pro compatible audio.

There are a lot of options for creating mini-ITX projects and you should review those choices so that the mainboard will help you accomplish your goals for the project. This project has the focus of creating a functional dekstop with DSL.

The case is a Casetronic C134 mini-ITX Case that is about the size of a CDROM. Notice the carrying handle to make it more mobile. When you are buying a case make sure you verify that the mainboad will work with the case as there is little room for error in these small formats. There are several things that can cause major frustration when buying a case. Be careful to watch for the requirement of special low height RAM or heat sinks as you must verify that your mainboard choice will work with the case.


The power supply is also an important choice as you will want to make sure that the power supply is compatible with your mainboard. The example shows a 60W power supply. Often the power supply will come with the case that you purchase.


Advantages of mini-ITX

There are several significant advantages of mini-ITX. The first of course is size. This form factor will provide you with significant size reduction so that you can either consider taking the project as a mobile solution or save on desktop space. You could easily save 90% in space reduction vs. a desktop case. Noise is another advantage. Many of these from factors have no fan options. This may make a much more enjoyable experience for the user. The other major value is power consumption. A typical desktop situation may be a 17” CRT monitor and a ATX format tower with a 350 watt power supply. The 17” monitor will often use 350-400 watts making a power trail of 700-800 watts for a nice desktop. Typically these wattage figures are maximums and no system runs at these levels for long. But you will need to account for these issues so that you could if you had to. Now this does not even touch on the aspect of heat. If you put this kind of setup into a room with 30 other such machines you will need to turn on air conditioning to maintain a livable temperature and you would need to increase the electrical circuits in that room with additional circuits because one circuit could not handle this type of load from 30 such computers. Now I recognize that the home user does not have this kind of problem with 30 computers but I have worked with institutions where this is a serious financial issue. Anyways, the advantage here is that you can move from looking at 700-800 watts to 95 watts if you also purchase a 17” flat screen. This is a huge savings on power and suddenly the heat issue is non-existent.

Getting Started

Here is an example of inserting the power supply into the case. Notice that the power connections provide the standard ATX connector that will connect to your mainboard. Be

sure to connect the ATX connection so it clips into place. You can see the clip is visible in the illustration. Never start the power supply without being connected to the mainboard, it could cause adverse reactions.

In the lower left hand aspect of this picture you can see that the power switch is located here. The power button just extends outside the case in the lower left.


This picture shows the ATX connection from the power supply to the mainboard. There is only one way to put these on, but make sure the click into place.


Be sure all of your connections are tight and secure to the power supply. This connection provides the lights that indicate that the computer is running and that the hard drive is active.

Once you get the power supply inserted correctly then attach the mainboard

This picture illustrates that the power supply is connected (left hand side) separately and then the mainboard is attached. Notice the height of the two heat sinks in the illustration the height of the black heat sink is for the processor and you must be sure that it is not so high that the cover for your case will not fit. Check this before you buy. Again, there is no margin for error. Now you will also need to be alert for low-rise RAM. Many cases this is not an issue, you can use a normal RAM chip. But, there are cases where you will be required to purchase special RAM to fit that does not rise as high as other RAM chips.

Here the RAM is PC 133, a 129MB chip. Be sure to check mainboard requirements before you purchase RAM.


If you look closely you will see one RAM chip is in place. Be sure to click each white retainer on each end. These chips are inserted straight down, not at an angle, be careful as you can actually break something here.

This is a picture of the hard drive and the 40 pin connection to the primary controller. Notice that the hard drive is drive that a laptop would use and therefore uses a floppy power connection instead of the typical mutext connector for larger hard drives. Old disk drives for laptops can be had at reasonable prices.

Below is a good picture of RAM inserted as well as the blue connectors for the primary and secondary controllers which are your connections for hard drives and CDROMS.

Often the hard drive and CDROM that you put into these projects will attached to the cover of the case so actually your hard drive and CDROM are almost on top of the processor and mainboad. Again, the margin for error is thin so make sure all of your components will fit together.

Here you see the 40 pin connection to the mainboard for the hard drive.

The example below shows that the hard drive is attached and the CDROM will be attached to the case to the right of the hard drive. This example shows an optional fan that comes with the case but is not mandatory as the example uses a fanless CPU.


Below is a picture of the hard drive attached to the mainboad. Notice that the connection used for a floppy is employed in this connection.


Here is a good picture of the power connections to the mainboard which usually include the hard drive light that flashes when used, a reset connection, a power lead indicator, a speaker and the power on/off connection. You will need to consult the mainboad manual that comes with the one you are using to find this information.

Once you have all of your components connected you will begin to prepare to put on the case cover. There is usually not much space so you will need to be careful sliding the cover on so you do not damage or disconnect the cabling. Take your time with this process as it will be time well spent.

Often the clearances are very small for the heat sink and cabling that is required to run the system.


The example below shows the case almost together and illustrates the typical abundance of airflow options to cool the case. Heat is one thing that you need to consider closely when putting together a mini-ITX because there is usually very little space for airflow inside the case.

In the image below the hard drive is under the plate. You can see the mounting screw holes in the case for the hard drive.