SUPER MICRO Computer Dual Processor AS 1020C-3 - Manual (Page 29)

Chapter 3: System Interface
3-3
HDD: Indicates IDE channel activity. On the 1020C-3 this light indicates
SAS and/or CD-ROM drive activity when fl ashing.
Power: Indicates power is being supplied to the system's power supply
units. This LED should normally be illuminated when the system is operating.
3-4 SAS Drive Carrier LEDs
Each SAS drive carrier has two LEDs.
Green:
When illuminated, the green LED on the front of the SAS drive car-
rier indicates drive activity. A connection to the SAS backplane enables this LED
to blink on and off when that particular drive is being accessed.
Red: The 1020C-3 features a SES2 compliant backplane that activates the
red LEDs, which indicate a drive failure. Please refer to Chapter 6 for instructions
on replacing failed SAS drives.