Asus DSBF-DM/SAS - Manual (Page 22)

2-2 Chapter 2: Hardware information
2. Hearbeat LED (for DSBF-DM/SAS only)
The green heartbeat LED blinks per second to indicate that the LSI 1068
chipset is working normally.
®
DSBF-DM Series
DSBF-DM Series Heart Beat LED
ON
LED1
LSI SAS 1068
starts working
3. CPU Warning LED
The red CPU warning LED lights up as a reminder if CPU is not installed or
not properly installed in the CPU socket 1.
®
DSBF-DM Serie
s
DSBF-DM Series CPU warning LED
ON OFF
CPU_WARN1
CPU1 not present CPU1 present
If the CPU warning LED lights up, the motherboard will not boot.