Asus M4N78 - Manual (Page 29)

2. Keyboard power (3-pin KBPW)
This jumper allows you to enable or disable the keyboard wake-up feature. Set this
jumper to pins 2-3 (+5VSB) if you wish to wake up the computer when you press a key
on the keyboard (the default is the Space Bar). This feature requires an ATX power
supply that can supply at least 1A on the +5VSB lead, and a corresponding setting in
the BIOS.
3. USB device wake-up (3-pin USBPW1-6, USBPW7-12)
Set this jumper to +5V to wake up the computer from S1 sleep mode (CPU stopped,
DRAM refreshed, system running in low power mode) using the connected USB
devices. Set to +5VSB to wake up from S3 and S4 sleep modes (no power to CPU,
DRAM in slow refresh, power supply in reduced power mode). This jumper is for the
internal USB connectors that you can connect to additional USB ports.
Chapter 1: Product introduction 1-19