Build Your Own Computer: Word of Warning

The first things we need are the words of warning and each one will be important and for a very good reason when you build your own PC.

  • Stay Safe: Never, ever, ever build your own desktop computer while it is still switched on. I accept that from time to time I will do it with certain computer parts, but for the sake of not frying your computer (or yourself) I always recommend that you leave your desktop computer plugged in wherever possible but the power switched off at the wall and on the power supply of the computer (if fitted).

  • Check your compatibility. When you build your own computer; it is easy to buy incompatible computer parts. Most components that have developed over the years will have an identifier on it and I will refer to them during the text, but if you buy the wrong item then try to install it; shops  will not take computer parts back.

  • Everything fits together quite easily. If you are struggling to make that "male and female" connection, you might have the wrong part or the wrong way round as you build your own computer. Computers are increasingly designed to be user-friendly and ensuring the correct orientation of computer parts is now the main problem.

I can not stress how important it is to be aware of this; so much so that I even placed it in an article about sourcing your computer parts.



Putting Everything Together

To build your own computer is easy if you have a bit of confidence, the understanding that if something does not fit first time then there is something wrong; and the computer parts required to build your computer.

Computer parts; the phrase might sound daunting in itself with talk of bulldozers (the new processor from AMD), Ivy Bridge (the new interface between processor and motherboard from Intel) and solid state hard drives; but the combinations of what you can and can not combine are generally limited to a few options, which if you are building your own computer from scratch are even easier to understand as technology develops. If you have not sourced your computer parts yet then a little reasearch goes a long way to finding the right computer components for you.

Because the appearance and layout of most components will differ, anything pictured may not be an exact match to what you have in front of you and because of the different sizes and shapes that some components come in; there may be an easier way in some instances.

......and also for a caveat emptor; this article is about building the hardware for your new PC computer. In order for it to work as a computer you must also install an operating system such as Windows 7 or Linux.

If you build a desktop computer and do not install an operating system; it will not work!

Understanding Your Case

The first thing that you need is your new computer case. When you build your own computer there will be a number of important cable connections inside for power and reset buttons, any case mounted USB or Firewire ports and occasionally built in fans. The first thing we need to do is to make sure that we have no built up static electricity and I will never do anything before ensuring that I have wired myself up to ground and maintain an earth. As a matter of course I wear an earthing device around my wrist and attached to my desktop computer case, however even something as simple as rubbing your hands on a tumble dryer anti-static sheet will help.

The first thing to fit into the case will be the power supply. This will actually help us to mitigate some of the issues surrounding static electricity and give us an earth; hence why I prefer to fit this first.

Power Supply

Power supplies generally come with either a standard set of mounting points (to match the majority of desktop computer cases) or an adapter to achieve the same goal. To fit a power supply you must place it inside the case so that the power connection is accessible from the back of the case and that any fans built in to the power supply on other panels; are  pointing into the case and not against the side walls.

Ideally when the power supply is connected to your new PC and screwed in place; you should connect the power supply to the mains but do not turn on the power supply at the wall. the reason for this is that the power connection still supplies an easy earthing for electricity to escape without cooking either your new desktop computer parts or yourself.

Hard Disk Drives

Usually, you will find that any internal DVD drives and your new hard disk drives (HDD) should go in next. This might sound strange to someone learning how to build your own computer, but as the majority of cases and drives are required to be secured from the inside of the case, it is often easier to do this than install them later.

SATA HDD(82353)Credit: of the differences in size, DVD/CD drives and hard disk drives are usually separated within the case. The DVD drives will be secured in drive bays which are the largest bays usually found in the front and at the top of a computer case, located in 5 1/4 inch (or 5.25 inch) drive bays. Hard disk drives are usually installed in smaller 3 1/2 inch (or 3.5 inch) drive bays towards the bottom, of the front of the case.

The hard disk drive shown here is in fact upside down but shows you the connections as well. When you install your hard disk drive the circuit board shown here should be on the underside as you look at it.

In a similar way to the power supply, the installation is simply by sliding the drives into place and securing them with screws. Unlike the power supply though, the screws will secure internally to the drive bay housing so that when the sides of the case are secured, they are not visible.

Although you could do so, I would not connect your power supply cabling to any of the drives yet as this will limit your freedom fit other components in the case.

Building Your Motherboard

The next part to build your own computer is to assemble the motherboard, processor and RAM. This is best done outside of the computer case and installed as a single unit. It is possible to purchase pre-built kits containing all of this if you are building your first computer, but you can buy them seperately and do it yourself.

A Motherboard and ProcessorYou should have four items in front of you; the processor, the motherboard, one or more RAM cards and the fan/heatsink for the processor. The image here shows a motherboard which has its processor and fan/heatsink attached, but no RAM; you can see pairs of white clips in the background where the RAM will attach, hidden by the fan and heatsink in this instance.

Depending on your motherboard you should need to either unclip or release the processor socket so that it is open. This does vary by motherboard but is usually a small lever - check your manual if you are unsure - and line up your processor in the slots that are open. The processor will only fit one way to the motherboard; the processor will be slightly outshaped with a triangle of pins missing from one corner to prevent the processor being inserted incorrectly into the socket on the motherboard. Once the processor is in place you should secure it to the motherboard by locking the lever back in place.

Next you need to lock the processor cooling fan over the processor assembly. Again this differs  on whether you have an AMD or Intel based processor and motherboard installation; 

  • If you have an AMD processor then the heatsink will affix over the processor using clips - sometimes using a lever, sometimes you will need to ease the clips into place with care and flathead screwdriver to stretch the clips over the holding pins. 
  • If you have an Intel processor then the heatsink will attach via four pins which anchor the corners of the heatsink to the motherboard. 

Finally you have to plug the RAM in. This will go into slots on the motherboard which lock the RAM in via retaining clips. Open the clips as far as they go (about 20 degrees) and insert the RAM, which is designed to only fit into the motherboard in one orientation. It is important to keep the RAM level so that pressure is put on both ends and the retaining pins automatically lock the RAM into place.

The completed (or pre-assembled) motherboard should now be installed into the computer case. Around the motherboard there will be screw holes in the four corners and other strategic points to keep the motherboard secured. With your case you will have included a number of mounting screws which line up with these motherboard holes; by screwing them into the pre-threaded holes on the inside of the case.

Your motherboard will have come with a silver mounting plate. This is to secure the external posts to the cases for attaching keyboards, mice, monitors etc. The place where this plate should be fixed to the case should be obvious and it is simply required to push the plate into place as you build your computer.

The ports on the motherboard should then be lined up with this plate and the mounting screws which you have attached to the inside of the case will now line up with the motherboard screw points and can be screwed down. It should be noted that these ports will always be in the top left corner as you look at your newly installed motherboard.

We are now in a position to start attaching wires and giving power to the computer parts as we build your new computer.The most important cable to attach last is the connection from the power supply to the motherboard.

Wiring Your New Own Computer

So we will start here with attaching the case to the motherboard; there should be a range of wires coming from the front of the case where there are power and reset buttons, and quite often USB or Firewire connections as well.

The wiring is usually clearly labelled. It is less obvious on motherboards although the general consensus is that the connection pins for your front panel will be on the bottom right corner as you look at your newly installed motherboard. Because the configurations are different for each motherboard manufacturer; you must refer to the motherboard manual to make sure that you wire the connections from the case to the correct pins on the motherboard.

In the instance of USB or Firewire connections, these are single plugs that again are usually found towards the bottom of most modern motherboards and your manual will show you where they are.

As we build you computer we will now connect your desktop computer's optical and hard disk drives to the motherboard. As we are talking about building your NEW computer we will assume that you have SATA optical and hard disk drives. These are connected by wires that have small connections that are slightly L shaped to aid a successful attachment and can only fit one way, but it does not matter which end of the cable connects to the motherboard or your device.

Now is also the time to wire up the power to the optical and hard disk drives. The connectors for this are a similar shape to the data cable connections, but are slightly smaller, attaching to the drives next to the first cables that you attached. 

Your New Graphics Card

A Fanless PCI Graphics CardWe now come to (optionally) connecting the graphics card. Most motherboards only come with a single graphics card slot, immediately below the motherboards ports at the read of the case. It is approximately the same size as the standard PCI expansion slots, but will be set slightly towards the centre of the board.

If you remove the graphics card from its anti-static bag, you will see that there is the length of the graphics card and a small metal plate at a 90 degree angle to it. This smaller plate is designed to fit to the rear of the case and lock in using a single screw. The specifics of how this is done is case-by-case and you should check your manual.

The Last Connection - The Motherboard PSU

As you build your own computer we come to powering the motherboard. Most modern motherboards now need a 24 pin connection; dependent on the power supply you will either have a 24 pin connection, or more like a 20 pin connection with a separate 4 pin adapter that you connect in together.

In the majority of instances this is the only connection you need to make. If you have purchased high-performance equipment then a second connection with a 4-pin connector may need to be made separately close to the processor.

In all instances the power supply connections will only plug into one place on the motherboard due to the shapes of the connectors. This is to prevent you melting your new desktop computer and it is essential that you do not force any connectors where they do not fit.


That's It

You should now have a brand new, fully operational computer. At this point you should be able to power the computer up and be prompted by the hardware to tell you that there is no operating system installed. That is a whole new article (or just buy Windows 7 and follow the instructions) and you will built your own computer, sourced by you and all done..... by you.