Asus P9D-MV - Manual (Page 43)

ASUS P9D-M Series 2-23
2.6 Onboard LEDs
1. Standby Power LED (SB_PWR1)
The motherboard comes with a standby power LED. The green LED lights up
to indicate that the system is ON, in sleep mode, or in soft-off mode. This is a
reminder that you should shut down the system and unplug the power cable
before removing or plugging in any motherboard component. The illustration
below shows the location of the onboard LED.
2. +5V Power LED (+5V_LED1)
This LED lights up when the Power-on button is pressed and the system is
on.