Building your PC:
Assembling and Installing the Motherboard

The CPU (shown left) is a pre-used item, so it has some thermal compound still on it. This is not an issue however, and more compound will be added during the next stages of the assembly process. You should also note the notch and the gold triangle on the bottom left hand side of the CPU. This marks the point where a single pin is missing on the chip's underside. This there as an aid to properly orienting the CPU in its housing on the motherboard. Indeed, because of this there is only one way that the chip can actually fit into the motherboard itself.

The CPU itself sits in the socket indicated by the arrow on the image of the motherboard presented on the left. This is a special type of socket called a ZIF (zero insertion force) socket.

The pins on the underside of the CPU are very fragile. As a result the ZIF socket incorporates a lever that's used to move two plates over one another. When open obvoious holes are visible and it's easy to drop the CPU into these holes. As the lever is pushed back down the two plates are brought together so that a tight grip is maintained on each pin of the CPU. This secures he CPU in place and provides for good electrical contact to each pin.

The image presented on the left shows an open zif socket with the locking lever raised up into the vertical position. If you look carefully at the image then you will see that two pins are missing from the upper left hand corner of the zif socket near the lever. This is the position that the notch and the golden triangle of the CPU should be aligned with.

Making sure that you're wearing your anti-static wrist strap and that it's hooked to an earth metallic object (such as a water pipe), lift the CPU and carefull align the notch with the lever and drop it into place. If your alignment is correct then the CPU should drop into place so that it aligns flush with the base of the ZIF socket.

The image on the left shows a CPU correctly inserted into the ZIF socket. The notch and gold triangle align with the socket's handle. You can also see that the CPU's base is flush with the ZIF socket itself. If your alignment is correct then the CPU will drop into place with no force applied. If you have to push the CPU down then you haven't oriented it correctly.

If you haven't positioned the CPU correctly simply raise it up from the ZIF socket, look for the missing pins and lign the notch or golden triangle (or golden dot) on the CPU with the missing pins. Once the CPU drops easily into place you're ready for the next stage of assembly.

Once the CPU is seated correctly in the ZIF socket you need to lock it in place. This is simply done by taking hold of the lever and pulling it down. Near the base of the downward arc you should feel some resistance as the two plates come together to grab the pins of the CPU. Pull he lever down past this point and house it securely in the plastic restraining pins. Your CPU should now be held securely in the socket.

Once the CPU is securely in place apply a little thermal compound to the centre of the CPU (I tend to use 'Arctic Silver' myself and a pea-sized drop is more than enough.

Now that the CPU has been securely added to the motherboard nd prepared it's time to add the thermal protection for the CPU: which effectively means a CPU and a fan. In my case the CPU and fan came as a single assembly (as on the left) and they are ment to be secured by two spring clips.

In actuality, addding he heatsing and fan assembly is simplicity itself. Simply lift it up and sit it securely on top of the CPU. Try not to jiggle it too much as you set it down though as this can cause too much smearing of the thermal compound.

Usually the heatsink itself is oblong rather than square so that it will only fit on top of the CPU in one of two ways. Even then you should make sure that the cable associated with the fan can easily reach to and be housed in the fan power connector on the motherboard. This is usually either on the outside of the motherboard (as in my case) or is situated on the inside of the motherboard across from the zif socket lever hinge.

Make sure, however, that you check where the power socket is before you put your heatsink down on top of your CPU otherwise you will smear the thermal compound all over the place (and it's a pain to clean up, believe me).

Ro securely attach the heatsink and fan take the spring clips, hook one end int othe plastic housing on the motherboard (leftmost image). Once you've done this use a small flat-head screwdriver to lever the free end of the spring clip down and into the plastic holder on the other side. Repeat this on the other side of the heatsink and fan assembly. Once this is done the heatsink is now being pressed down firmly on top of the CPU, ensuring good thermal contact between them.

With this done, the CPU should now have been properly inserted into its housing.

After securing the heatsink and fan above the CPU the next stage is to clip the fan's power connector into the power socket on the motherboard. This is normally a three-pin connector (as shown on the left) and in general is to the right of the CPU housing on the outside of the motherboard. The power plug will only fit into this socket in one orientation so it should be an easy matter to marry the two together. Once this is done you have successfully completed the installation of the CPU.

The motherboard I've chosen to use has two memory slots (left, top), accommodating up to 1GB memory modules each. For the moment I've chosen to install two memory modules of 512MB each, giving me a total of 1GB of memory.

Though the manufacturers are different the memory modules are equivalent, both being 400MHz PC 3200 modules. Again, as memory modules are sensitive to static charge I usually install these in the motherboard before assembly in the case and I ensure that I'm wearing an anti-static wrist strap whilst performing the installation.

The image on the left shows the motherboard's memory banks with bank1 already filled. When inserting memory, because they are assymetric (ie the notch is closer to one end than the other) the memory modules will only fit one way. Before inserting the memory module, however, make sure that the tabs on the sides of the memory slots are pulled down. This will allow easy insertion of the memory. Below I demonstrate precisely how to insert a memory module.

The images on the left show how to insert a memory module. First make sure that the two tabs on the sides of the memory slot are pressed down. Seat the memory into the slot then press down first on one side then on the other (as on the right hand pane). The memory module should easily be pushed down and the tab should spring upwards and click into place to hold the memory module securely (leftmost image). Repeat this on the other side of the memory module and it will be seated properly.

If this has been done correctly then both (or one) memory modules will be seated securely in place and the restraining tabs on both sides of these will be upright nad will be locking the memory modules securely in place.

With both the CPU (and its associated heatsink and fan) and the memory modules your motherboard should look something close to the image presented on the left. You're now ready to prepare the computer's case so that the motherboard can be placed into the case and affixed in place.

Modern motherboards are no longer uniform in size and do not exactly correspond to one another in terms of the peripherals they support and the connections that they offer. As a result each motherboard is supplied with its own back plane insert. This is a thin sheet of steel that contains all the holes needed for the various connections supported by the motherboard. Around the rim of the back plane plate are a number of small metal nubs that will aid you in affixing this plate to the back of your computer; which will need to be done before the motherboard is inserted into the computer.

At the back of your case you will see either an oblong hole (as in my case, left) or you will have either a blank metal plate covering it or a standard insert. You will need to punch this plate or insert out so that you can replace it with the insert that came with your motherboard. Usually a quick tap with the back of a screwdriver will be enough to dislodge this. Once you have a clear hole you can put the appropriate panel for your motherboard in place of the original.

First take up your back plane insert and align with the hole in the back of your case (on the inside of the case). It's usually easier to push in one corner and then to go around and tap gently with the back of a scrwedriver. You should feel the metal nubs popping into place as you tap. Continue going around until the plate snaps securely into place, as in the image on the left.

Tipping the motherboard on its side you will see a large space inside the box where the motherboard itself will fit. As you will notice, the base plate on the bottom of the case is metal. If the otherboard sat directly on this it would simply short out, rendering it entirely useless.

As a result you will need something to keep the motherboard off the floor of the case. These somethngs are called 'spacers' and are generally either plastic or brass risers that lift the motherboard off the floor of your case. You will find them contained in a packet of screws that came with your motherboard.

In my case the spacers were brass screw inserts each intended to physically screw into the base plate of the case.

A pair of these screws are shown on the left. They are hexagonal in cross section, have a screw on their base which allows them to be inserted into the motherboard and they have a thread in their upper surface that allows the motherboard's retaining screws to be inserted into them.

The spacers themselves need to be inserted into screw holes on the base plate of the case: holes that need to align with the places for the retaining screws on the motherboard.

Probably the easiest way to find out where the spacers should go is to do a test placement of the motherboard. Attach your anti-static wrist strap then lift the motherboard (it's probably safest to do this by grabbing the CPU heatsink (as in the image). Carefully lower the motherboard into the case and align with the back panel. By comparing the screw holes on the motherboard (the silver-ringed holes to the front left and front right of the image) with the holes at in the base of the case (they won't match exactly as when you finally seat your motherboard the back ports will protrude slightly from the back of the case. Once you've identified the appropriate holes attach the spacers by screwing in with a pair of pliers.

Once all the spacers are in place, gently lower the motherboard into place. It's probably easiest to do this with the back of the motherboard (where the external ports are) angled down slightly. This way you can ease the ports through the holes in the back plate and if you've done it correctly you should see something like the image above. You can how ease the motherboard down onto the spacers and begin attaching it in place.

It's now a simple case of screwing the motherboard securely into place. If the spacers have been placed correctly your motherboard will sit on top of them. There will either be four of six retaining screws that need to be attached (depending on the size of your motherboard). Once these are securely attached all you need to do is to attach the power cables to the motherboard and this stage of the build is done.

First locate the motherboard power plug from the PC's power loom (see the next page on attaching drives for an explanation of the power loom). This is the large 20-plug power connector (as shown left, top). This fits into the 20-socket power connector on the motherboard (usually located near the memory slots). The tongue on the plug fits over the triangular protrusion on the socket (upper surface) to lock the two securely. Simply position the plug in the socket with the tongue over the flange and push down until you hear a click.

If all is well then the plug will fit securely into its socket, as shown in the image on the left. This is a critical part of the build process as it's this cable that provides the power for the entire motherboard and for any peripherals attached to the ISA slots (such as the graphics cards).

After the main power to the motherboard, the next step is to attach the power to the CPU. For modern CPUs their power requirement has increased so much that they require their own power supply. This is generally located somewhere near the CPU itself and is a square four-way socket (above left). This is matched with a four-way plug from the power loom (above, middle). Like the main motherboard power socket this also has a tongue that snaps securely over a protrusion in the socket so that it's only possible to insert it one way and once inserted correctly it fits securely into the cocket (above right).