Never connect a USB cable to the IEEE 1394a connector. Doing so will damage the motherboard!

You can attach a FireWire/1394 cable to this connector if your chassis suppots the front panel IEEE1394 port. Connect the 1394 cable to ASUS Q-Connector (1394, red) first, and then install the Q-Connector (1394) to the 1394 connector onboard.

13.ATX power connectors (24-pin EATXPWR, 4-pin ATX12V)

These connectors are for an ATX power supply. The plugs from the power supply are designed to fit these connectors in only one orientation. Find the proper orientation and push down firmly until the connectors completely fit.

M3A78-EM

 

 

 

 

 

 

 

 

 

 

 

 

ATX12V

 

EATXPWR

 

 

 

 

 

 

 

 

 

 

 

 

+12V DC

 

 

 

 

 

 

+12V DC

+3 Volts

 

 

 

Ground

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GND

 

 

 

 

 

 

GND

+12 Volts

 

 

 

+5 Volts

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

+12

Volts

 

 

 

+5 Volts

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

+5V Standby

 

 

 

+5 Volts

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Power OK

 

 

 

-5 Volts

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ground

 

 

 

Ground

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

+5

Volts

 

 

 

Ground

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ground

 

 

 

Ground

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

+5 Volts

 

 

 

PSON#

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ground

 

 

 

Ground

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

+3

Volts

 

 

 

-12 Volts

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

+3

Volts

 

 

 

 

+3 Volts

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

M3A78-EM ATX Power Connector

• We recommend that you use an ATX 12 V Specification 2.0‑compliant power supply unit (PSU) with a minimum of 300 W power rating. This PSU type has 24-pin and 4-pin power plugs.

•If you intend to use a PSU with 20-pin and 4-pin power plugs, make sure that the 20-pin power plug can provide at least 15 A on +12 V and that the PSU has a minimum power rating of 300 W. The system may become unstable or may not boot up if the power is inadequate.

•Do not forget to connect the 4-pin ATX +12 V power plug; otherwise, the system will not boot up.

•We recommend that you use a PSU with higher power output when configuring a system with more power-consuming devices. The system may become unstable or may not boot up if the power is inadequate.

•If you are uncertain about the minimum power supply requirement for your system, refer to the Recommended Power Supply Wattage Calculator

at http://support.asus.com/PowerSupplyCalculator/PSCalculator. aspx?SLanguage=en-us for details.

•You must install a PSU with a higher power rating if you intend to install additional devices.

ASUS M3A78-EM

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