Hardware Reference
In-Depth Information
Figure 19.26. Attaching an eight-pin EPS12V motherboard power connector. This type of
connector is split into two four-pin connectors compatible with the ATX12V standard, so it can
be used with motherboards compatible with either standard.
Note
Many power supplies feature a 115/230V switch on the back. If this is improperly set, the
system won't power up. Refer to
Chapter 18
for detailed coverage of power supplies and the
various types of power supply connectors, including the newer 24-pin ATX 2.x and eight-pin
EPS12V types.
Connecting I/O and Other Cables to the Motherboard
You must make several connections between the motherboard and the case. These include LEDs for
the hard disk and power, an internal speaker connection, a reset button, and a power button. Most
modern motherboards also have several built-in I/O ports that have to be connected. This includes
ATA/SATA host adapters and front-mounted USB or IEEE 1394 ports. Some boards also include
additional items such as built-in video, sound, or SCSI adapters.
If the board is an ATX or BTX type, the connectors for all the external I/O ports are already built in
to the rear of the board.
Use the following procedure to connect the cables needed for onboard I/O:
1.
If your system uses an internal floppy drive, connect the floppy cable between the floppy drives
and the 34-pin floppy controller connector on the motherboard.
2.
Connect the Serial ATA and Parallel ATA cables to the drives and host adapter ports on the
motherboard (see
Figure 19.27
). Typically, older systems will use the primary ATA channel
connector for hard disks and the secondary channel for optical drives. Most newer systems will
use Serial ATA connections for the hard drive and Parallel ATA for the optical drives, or
