Asus ESC500 G3 - Manual (Page 56)

Chapter 3: Motherboard information 3-8
3. Standby power LED
This motherboard comes with a standby power LED that 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.
4. DIAG_DRAM
The DIAG_DRAM lights up when the installed DIMMs incompatible with the
motherboard or improperly installed. When using the MemOK! switch for automatic
memory compatibility tuning, the DIAG_DRAM will blink.