Click on Product Views.
D - CPU Fan Connector (Processor Fan)
F - Main Power Connectorhttp://www.playtool.com/pages/psuconnectors/connectors.html#atxmain24
G - Floppy Disk Drive Connector
H - Parallel ATA IDE Connector
M - Clear CMOS Jumper
N - Front Audio Connector (Audio ports in Front Panel)
O - S/PDIF Connector
P - System Fan Connector (Computer Case Fan)
Q - IEEE 1394 Connector (Firewire ports in Front Panel)
R - USB Connectors (Front Panel)
S - Front Panel Connector
The front of your computer is the Front Panel.
The area of contact pins on the motherboard, that the main wires go to, is the Front Panel header.
The above is the pinout for the Front Panel header.
T - SATA Connectors
A SATA data connector on the motherboard has 7 contact pins.
Between it, and the SATA power cable, the SATA data cable's connector is shorter in width,http://en.wikipedia.org/wiki/File:SATA_ports.jpg
Note the L shaped slot in the SATA data cable's connector, at top;
and the corresponding L-shaped locating lug on the motherboard connector, shown at bottom.
SATA power cable general example,http://www.playtool.com/pages/psuconnectors/connectors.html#sata
The SATA power cable's connector has a Lock tab on top. Squeezed down with the thumb tip to release when removing.
Looking at the 6 SATA connectors on the motherboard, you will note they are marked in-between the connectors, and at the outside edge of the motherboard. SATA_1, SATA_3, SATA_5, SATA_2, etc.
If using more than 1 harddrive, the harddrive that has the Operating System, is generally plugged into SATA_1.
The beauty of SATA is however, that you can plug whatever SATA device you want, into whatever SATA connector on the motherboard, and BIOS will find the device.
Mean, for one,that you can plug the harddrive with the O/S into SATA_3, or SATA_6, or SATA_4, etc; and BIOS will still find it.http://www.ascendtech.us/acer-rs780-mb-saq09-004-motherboard_i_mb64ambsaq09004.aspx
Scroll down to the photo under the Specifications chart. It's a Top View.
The power cable, and corresponding connector on the motherboard that is Not stated on Gateway Support, is a 4-pin ATX +12 Volt power cable,http://www.playtool.com/pages/psuconnectors/connectors.html#atx12v4
Motherboard in the Top view is shown as it is, when installed in a computer case. Go above the top of the Processor socket to the edge of the motherboard, then over to the left.
Whitish square 4-socket hole connector.
4-pin ATX +12 Volt.
Above the top right corner of the Processor socket, and between the edge of the motherboard is the CPU_FAN connector.
Front Panel header bottom/right corner of motherboard
The four Yellow USB headers are to the left of the Front Panel header.
The Black Firewire (IEEE 1394) header is to the left of the USB headers.
The SYSTEM_FAN white connector is to the left of the Firewire connector.
SPDIF_OUT connector to the left of the System Fan connector.
F_AUDIO red connector to the left of the SPDIF connector
To the right of the Blue and Yellow ram memory slots, is the 24-pin ATX main power cable connector. To the right of it is the Black 34-pin Floppy Drive connector.
Below the Floppy Drive connector is the Blue 40-pin IDE connector.
For additional questions please post in a Comment.