Start by removing the cover(s) from your case. Set the case so that the base plate, the part onto which you will attach the system board, is flat on the table. If it’s a tower type case, lay it on it’s side, if it’s a desktop type case just set it on its “feet.” Speaking of feet, look over that bag of parts; most new cases require that you snap in the little plastic feet. Now is a good time to do that.
Before you go any further, take the system board and set it down into the case. Note that there are blanked off holes and slots in the back of the case which correspond with the various connectors that must plug into the system board itself, or the cards that will fit into it. If you have the room, be prepared to place the video adapter, sound card and whatever else you have as far apart as possible. Don’t worry if you have to plug them in side by side but it sure makes it easier to work on the computer if you can get your fingers in between the cards. Remove the blanks for the holes you’ll need once the computer is assembled. Some people prefer to remove all the blanks, so all the holes are open. This saves the trouble of doing so in the future if you decide to add new cards or parts and has the added benefit of allowing air to circulate in the case, improving cooling. Install the front and rear case fans if they didn’t come pre-installed. Check that it will blow in the correct direction, which is usually indicated on the frame of the fan by a little printed arrow. For more information on cooling, check out our cooling tutorial.
Now you know how all the parts will fit into place. Look through the hardware that came with the case. You should have a packet of small stand-off/spacer screws. These are usually brass, will thread into the case base plate and will support the system board. Screw them in place in the case and then set the system board down on them. You should now be able to use some small screws to fasten the system board in place. The screws will thread into the tops of the brass stand-off screws. Hopefully you got also some washers made from a non-conductive material, such as plastic, to use with the screws to absolutely eliminate the possibility of the metal head of the screw touching anything on the board it is not supposed to touch. If there are any screw holes left unsupported by the stand-off screws, look for plastic snap-in support grommets. These will snap into the remaining holes in the system board from underneath and help to support it. It is important to make sure the system board is well supported up, away from the metal case or it could short out.
Once the system board is secure you can plug the long male connector from the power supply into the female plastic connector on the system board. Here is where you will see The Two-Fold Secret in action. The plug from the power supply will only plug in to one receptacle — it will not fit any other connector. What’s more, it will only fit one way. You can’t plug it in backwards or upside down. Once plugged in your system board will have power to it so proceed with caution.
Next you can plug the CPU in place. There are now several different types of CPU to system board sockets available. If you’ve shopped carefully and have the correct combination of board and CPU, and if you read the manual you will see that there is only one way to plug the CPU into the socket. Be patient and gentle. Look the CPU and socket over carefully before you assemble them.
The RAM should be installed next. It should only fit one way. If you look carefully at the bottom of each RAM stick, you’ll notice that there is a notch in it that makes it fit into the socket on the board only one possible direction. Again, be gentle, don’t force it.
Now you need to set the jumpers for the CPU and, if applicable, for the RAM. Look in the manual for the CPU setting charts. There will probably be (at least) four charts for four “banks”, or sets of jumpers to control the CPU settings. Each of these must be correct in order for the computer to function properly. The jumper banks will likely be broken down as follows:
- The CPU I/O voltage. This is a general setting for whole families of CPUs. There will probably be one setting for all older CPUs and one for newer ones. Whatever the arrangement, the manual should spell it out clearly.
- The CPU/Bus speed. This is the multiplier for the CPU speed. You should have a chart in your manual with settings for X2.0, X3.0, X4.0, X4.5, etc. This setting works with the CPU clock speed (next item) to set the final CPU speed.
- The CPU clock. This setting controls the speed (MHz) at which the CPU functions. For example, a 400MHz Pentium II CPU should be jumpered at 100MHz with the BUS speed multiplier set to X4.0. Thus 100MHz X 4.0 = 400MHz. Or, if you have a 300MHz AMD CPU, the setting would be 75MHz X 4.0 = 300MHz. This figure is a close approximation of the actual CPU speed. When you hear a computer referred to as a e.g. “450 Celeron”, this is what someone is talking about.
- The CPU core voltage. Every CPU has certain specific core voltage requirements. Many chips have this figure stamped directly onto the chip itself. If you can’t find it there, look in the paperwork for the CPU. The manufacturers web page should also have this information available.
Not all motherboards have jumpers, some have switches. Other motherboards don’t have jumpers or switches, they have something called SoftMenu, which means you boot the PC when you have all the parts installed, and carefully look on that first black screen for a message that reads something like “Press DEL to enter Setup.” Check the motherboard manual for details how to enter the Setup menu, or BIOS. Then look in the BIOS for an entry called SoftMenu or CPU Menu. Here’s where you set the clock and bus speed. The advantage of this is that you don’t need to fiddle with those pesky little jumpers that have the nasty habit of jumping out of your fingers (that’s why they are called jumpers – I think) into the smallest crevice available.
Check the manual to see if your RAM requires any jumper settings. If so, just use the same methodical approach and you’ll be fine.
Now it’s time to plug in the ribbon cables.
Note: This article deals with IDE drives, since they are the most popular for the home user market. If you have SCSI devices in your setup, please check out our ultimate SCSI guide for details on how to easily install SCSI devices.
These cables connect the different drives (floppy drive, CD-ROM and hard drives) to the system board. Each ribbon is 12, 18 or 24 inches long, and will have two or three connectors. Note that the floppy drive ribbon cable will only plug into the floppy drive because of its different size. You can’t plug it into the hard drive or CD-ROM. Also, you’ll see that it will only plug into one connector on the system board. Most system boards label the connector “Floppy” or similar, so there is no mistaking where it goes. The floppy cable stands out a bit because it has a funny twist towards one end. Plug the connector at the end after the twist into your floppy drive, this is what makes it drive A:. If you plugged it into the middle connector before the twist, it would become drive B:. The connector on the other end of the cable, away from the twist, goes into the floppy controller connector on the motherboard. Additionally, each of the connectors for these cables will only fit into their respective sockets one way. This is accomplished with a locating pin placed on one side of the connector or with asymmetrically shaped connectors. It might be possible to jam one of these connectors into the wrong socket but it wouldn’t be easy to do (if you could do it at all) and you would almost certainly damage the connector in doing so.
The Thin Red Line
Nope, we’re not talking about the sorry excuse for a movie with the same name, but about the most important clue on how to connect the ribbon cables correctly. Along one side of the ribbon cable (both floppy and hard drive) you’ll notice a red stripe. This marks the side of Pin 1. On every hard drive and floppy drive and CD ROM drive you’ll find a marking somewhere around, over, under, at, near the plug that shows you where Pin 1 is. Usually this marker is a tiny number 1 printed or an obvious arrow pointing. The same applies for the opposite connector on the motherboard. Line up the red line on the ribbon cable with the marker for Pin 1 and you’re golden.
Each of the ribbon cables will have either two or three plugs; one at either end and a third plug (optional) closer to one end than the other. The end of the ribbon cable with the lone connector is the side that plugs into the system board. This holds true for both the floppy and HDD/CD-ROM ribbon cables.
The hard drive ribbon cable can plug into one of two connectors on the system board. Both connectors are for hard drive cables, but one of these is the Primary IDE connector and the other is the Secondary IDE connector. Each of these has a similar though specific function. Your system board will accommodate up to three separate individual hard drives along with one CD-ROM drive. All of these items plug into these IDE ribbon cables, however, there is a particular order in which these items are connected. For now though, let’s finish assembling the system board in the case.
Now look for a series of thin colored wires with small plugs coming from the inside front face of the case. These are the wires for the power switch, speaker, reset button, HDD light and fan in the front of the case. The little plugs will be labeled clearly. You will also notice that the plugs are notched, shaped asymmetrically and there will be a marking to indicate which is the number one pin. Now look at the corners of the system board for a series of little prongs sticking up. You’ll know you’ve found them when you see the labels on the system board itself for the POWER SWITCH, FAN, SPEAKER, HDD (for the hard drive activity light) and POWER LED. They’re usually all close together, bunched up in one corner of the main board. Note that the corresponding number one pins are labeled with a small triangular arrow head. They’ve made it basically foolproof. What with labels, specially shaped plugs and number one pin markers it’s a straightforward job of plugging all those items in.
You should consult your motherboard manual for some help with plugging these cables in. Any decent manual has a clear diagram explaining exactly which pins are for what and how to connect the cables to them. Also, keep in mind that you can’t really do much wrong with these cables. After you are done assembling and turn the PC on, watch the lights on the front of the case and make sure the switches work. If they don’t, simply turn it off, reverse the plugs for the item(s) that didn’t work, and you should be in business.