Asus P5B - Manual (Page 45)

ASUS P5B 2-2
3. Keyboard power (3-pin KBPWR)
This jumper allows you to enable or disable the keyboard wake-up feature.
Set this jumper to pins 2- (+5VSB) 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 A on the +5VSB lead, and a
corresponding setting in the BIOS.
2. USB device wake-up (3-pin USBPW1234, USBPW5678, USBPW910)
Set these jumpers to +5V to wake up the computer from S sleep mode
(CPU stopped, DRAM refreshed, system running in low power mode) using
the connected USB devices. Set to +5VSB to wake up from S and S sleep
modes (no power to CPU, DRAM in slow refresh, power supply in reduced
power mode).
• The USB device wake-up feature requires a power supply that can
provide 500mA on the +5VSB lead for each USB port; otherwise,
the system would not power up.
• The total current consumed must NOT exceed the power supply
capability (+5VSB) whether under normal condition or in sleep mode.
R
P5B
P5B USB device Wake up
USBPW2
(Default)
+5V +5VSB
2   2

2
USBPW90
+5V
(Default)
+5VSB

2
USBPW5678
(Default)
+5V +5VSB
2   2
R
P5B
P5B Keyboard Power Setting
(Default)
+5V +5VSB
KBPWR
2   2