Connecting the Power Supply & Motherboard

It's now time for connecting the motherboard (mobo) to the power supply and the other components. Remember the board is very fragile and is very easily damaged. Treat it very gently.

Take a minute and double-check to be sure your power supply is strong enough to run your mobo. Newer boards often require more power, if you don't have enough watts the mobo just won't run, OR it will over-heat the power supply and be a serious fire hazzard. Have the right power supply for your motherboard.

As always, ground yourself before you begin.

Connecting the Power Supply - Warning: The power supply must be turned off and unplugged from the electrical wall outlet.

Select the Correct Voltage - Check the red Power supply switch setting to insure it is set to 115V for North America, or 230v for Europe and other countries.
- For an AT and Baby AT Boards - Locate the two large 6-wire leads on the power supply. They are labeled P8 and P9. Connect these leads to the large 12-pin power connector on the mother board. This should be located behind the keyboard connector.
  
  It is very important to make sure the black wires are in the middle and directly next to each other. You may need to work with them to get them to co-operate, but they do fit.
- For an ATX Board - Plug power supply into the large 20-wire plug.
Connect the Processor Fan - Many processor fans will connect to one of the power supply leads. This allows an additional connector to be free for a drive while the fan becomes part a drive’s circuit.

If you see a 3-pin plug, then you can plug it into a small connector directly on the motherboard. The connector is often labeled something like "CPU_FAN1."
Figuring Out the Wires - Now, take a few minutes and mentally map out the wires and connectors. Look in the mobo manual to help you identify one connector from the next. From this you should get a clear picture of what gets plugged into what.

Study the case connectors and try to match them to case connector wires. The connectors are usually a big block of pins on the board's lower section.

In better cases, the pins will be labeled. But you will still need your manual to understand which label goes to which pin.

In better cases, connectors will be labeled informing you to which case feature it leads to. If they are not labeled, you will have to trace the wires back to their source to identify the feature they come from.

When connecting, consult the manual for pin 1’s to insure each connector is plugged in the right manner. Remember, if a feature is not working, you may only have to turn the connector around on the motherboard to make it work.
Connect the Turbo Switch - If you have one, connect it. If you don’t have one, roll up the wire and stuff it or secure it with a tie.
Connect the Power Switch - (For ATX boards only). On the switch box, you will see one loose wire hanging. Connect this to the power switch connector on the motherboard, instead of the power supply itself. The connector is often labeled "PWR" or "PWR_SW." Cover the connectors with electrical tape. Consult your manual if you need more information.
Connect the Reset Switch - Connected the reset switch to the motherboard. The connector is often labeled "RST" or "RESET." Consult your manual if you need more information.
Connect Power LED/Keylock Switch - If you have a keylock, many cases have these two devices on one 5-pin plug. Of course, without a keylock, the Power LED will be alone. The motherboard should be labeled accordingly. Just plug in the plug. If your system has separate plugs for each, connect them separately.
Connect the Turbo LED - Like the turbo switch, this is a relic from the past. You can connect it if you wish, although many boards just light it and don't really do anything with it at all. If you wish, you can skip it. Some also connect it to a different part, such as a SCSI adapter, and use it for SCSI drive activity instead.
Connect the Hard Drive Activity LED - This comes as a 2-pin or 4-pin plug. Sometimes only two of the pins are connected. Just plug it in to the 2 or 4-pin connector on the motherboard. It is usually labeled something like "HDD" or "HDD_LED." If this is connected incorrectly, the light may never come or it may stay on all the time when the PC is running. Consult your manual for more information.
Connect the PC Speaker -
- This usually comes as a 4-wire plug. Just plug it into the 4-pin connector on the motherboard.
- At times you will see the speaker connector on two 1-wire plugs. In this event, plug them into pins 1 and 4.
Connect the Floppy Disk Drive -
- Connect to the Power Supply - The smallest plug (connector) on the power supply will be for the 3.5 inch floppy. Locate it and plug in.
- Attach the Ribbon Cable - The ribbon cable for the floppy disk has a twist in it. Connect the floppy to the connector after the twist. If you have a second floppy, connect the second before the twist. There are no master/slave jumpers to set.
Connect the Hard Drive:
- Connect the Power Supply - Select an unused power cable lead from the power supply and plug it into the power plug on the hard drive. The plug will be keyed so that it will only go in the correct way.
- Attach the Ribbon Cable - The ribbon cable goes from the primary IDE controller on the motherboard to the hard drive.
Make sure the red edge of the ribbon cable is in line with Pin 1 on the drive. If you can' see Pin 1 marked, then it is the pin closest to the power connector. If you place the cable on backwards, you may get strange errors that make your new drive sound like it has died already.

If you are adding a second drive, simply choose a connector on the same ribbon cable that is not used. Most ribbon cables come with two connectors: one on the end and one mid-way. In this case, it doesn't matter which plug goes in hat drive. The computer looks at the master/slave jumpers to see which one is "C". Make sure to connect the other end of the ribbon cable to the primary IDE connector on the motherboard. Pin 1 will be labeled on the mobo, and align the red edge of the cable with it. Also, ATA-66/100 drives must have an 80-wire cable instead of the older 40-wire's. The ribbon cable will generally be included with the hard drive.
Connect the CD-ROM:
- Connect the Power Supply -Select an unused power cable lead from the power supply and plug it into the power plug on the CD-ROM. The plug will be keyed so that it will only go in the correct way.
- Attach the Ribbon Cable - Connect one of the two available plugs on the ribbon cable to the CD drive. Just choose the plug which can reach the drive best.
  
  If you have two CD drives, use the plug on the end of the ribbon cable for the top most drive, and the middle plug for the next lowest CD drive. Attach the other end of the ribbon cable to the secondary IDE port on the mobo. Like that of the hard drive, Pin 1 will be labeled on the mobo, and align the red edge of the cable with it.
- Attach the Audio Cable - This small 3-wire connector goes from an "Audio" plug on the back of the CD-ROM to a 3-pin plug on the sound card. If you happen to have on-board audio circuitry on your motherboard, the CD-IN plug will be on your motherboard and you can connect this now. Otherwise, you can attach it after you install the sound card. Some CD drives have both an analog and a digital audio out. Most of the time, people just use the standard analog audio, but if you wish, go ahead and use the digital. Your drive should come with audio cables for both options.
Double check all of the above connections and make sure all plugs and connections are firmly plugged in.