Rear View

The rear view of the Expansion Chassis is as below:

Item	Component
2	Power Supply Unit (PSU 2)
3	Power Supply Unit (PSU 1)
4	Left fan assembly; Fan 1 is located at the back; Fan 3 is located in front
5	Right fan assembly; Fan 2 is located at the back; Fan 4 is located in front
6	Secondary Expansion Chassis I/O module (top); redundant/failover operations supported with the primary Expansion Chassis I/O module (bottom)
7	Primary Expansion Chassis I/O module (bottom); redundant/failover operations supported with the secondary Expansion Chassis I/O module (top)
8	Serial Number/Asset Tag

The rear view of the Expansion Chassis with I/O module port connections are as below:

Note: These apply to both I/O modules.

I/O module LEDs

Item	LED	Action
1	ID LED/Button	Off: Normal state; I/O Module identification not illuminated Blue solid: I/O module identification illuminated
2	SAS 0	Off: No SAS activity Green blinking: SAS activity
3	SAS 1	Off: No SAS activity Green blinking: SAS activity
4	SAS Connection	Green solid: SAS connection on Green blinking: SAS activity
5	I/O module	Off: I/O module not functioning Green blinking: I/O module active

Power Supply Unit (PSU) LEDs

The PSU LEDs are located in the same position on PSU 1 and PSU 2. Location and description of the LEDs are as below:

Item	LED	Action
1	PSU Power	Off: PSU is not plugged in Green solid: PSU is plugged in; has power
2	PSU Status	Green solid: PSU is powered on Orange solid: PSU is not powered on