Seagate Exos X 4006 Series Hardware Installation And Maintenance Manual page 109

The CM has a number of ports, each with independent status LEDs. Those items in the state column with an asterisk (*)
indicate a fault condition.
LED Type
SAS expansion port Amber
Hardware fault
OK to remove
To replace a 5U enclosure controller module:
1. Complete the following actions to remove the faulty CM:
a. Facing the rear of the storage enclosure, carefully remove all CM connections.
b. Grasp the CM release latch between thumb and forefinger, then squeeze together to release the latch and handle.
109 Chapter 11 In-service field maintenance for 5U enclosures
Color State
On*
Fast flash* (1s on, 1s off) SAS Unit identification (UID) active
Slow flash* (3s on, 1s off) Non-critical SAS cable fault
Off
On*
Amber Flashing
Off
On
White
Off
Figure 82 Controller module LEDs to examine for fault conditions
Status
Critical SAS cable fault
SAS expansion port functioning properly
CM hardware fault
Part of sequence as CM comes online, on standby
CM functioning properly
Ready for removal, the cache is clear
Do not remove the CM, cache still contains unwritten data