EVGA X58 3X SLI - Manual (Page 34)

Post Port Debug LED and
LED Status Indicators
Post Port Debug LED
Provides two-digit POST codes to show why the system may be failing to boot.
It is useful during troubleshooting situations. This Debug LED will also display
current CPU temperatures after the system has fully booted into the Operating
System.
LED Status Indicators
Theses LEDs indicate the system’s status.
POWER LED (Yellow):
When the System is powered on: This LED is on.
DIMM LED (Green):
When the Memory slot is functional: This LED is on.
STANDBY LED (Blue):
When the System is in Standby Mode: This LED is on. This LED will
remain on as long as the motherboard is receiving constant power.
Debug LED with CPU
Temperature Monitor
POWER LED
(YELLOW)
DIMM LED
(GREEN)
STANDBY LED
(BLUE)