Acer AT350 F1 - Manual (Page 44)

3 System upgrades 32
Determining the drive status
Each HDD carrier features two status LED indicators (see page 6) to
display the hard drive status. If you are replacing a failed HDD,
determine which drive has failed by checking the hot-plug HDD status
indicators.
3.5-inch HDD
2.5-inch HDD
Description
Green Red
Onboard SATA or RAID card without SGPIO support
HDD present On Off
HDD access Blink Off
RAID card with SGPIO support
HDD present no access SAS: On
SATA:Off
HDD access Blink
HDD failure On
HDD removal Off Off
HDD insertion and rebuilding Blink (1 Hz)
HDD locate Blink (4 Hz)