DIMM (green/Orange)
On -->DIMM status is known and fault free.
Off --> DIMM status is unknown
Blinking --> If DIMM, Fault, and Self Test LEDs are blinking, DIMM failed self-test.
If DIMM and Fault LEDs are blinking, an operational fault has occurred.
If fast blinking (400ms On and 400ms Off), an operational alert occurred and is unresolved.
If it's non-production switch, Try resetting switch, if issue persists Log a support ticket to replace DIMM Module
■ pressing the Reset button. On the 5400 zl switches, this is the Reset button on the Management Module.
■ power cycling the switch (if both power supplies are being used, you will have to disconnect both power cords)
http://h20628.www2.hp.com/km-ext/kmcsdirect/emr_na-c03114710-3.pdf