User's and BIOS Manual (1.0b)

Chapter 3: System Interface
3-3
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 Serial ATA Drive Carrier LED
Each Serial ATA drive carrier has a green LED. When illuminated, this green LED
(on the front of the Serial ATA drive carrier) indicates drive activity.