M9K IOU third slot scsi-sas disk is not detecting

Hi Experts,

I am facing an issue with my M9000 hardware where as combined two CMU(0&1) and created Domain 0.

Both IOU0&1 populated with 3X3 Local hard disk with three slot respectively( 4th slot free).

First two hard disk of each IOU is getting detected, but third slot on each IOU disk is not getting detected.

Could you some one help on this.

XSCF> showboards -a

XSB  DID(LSB) Assignment  Pwr  Conn Conf Test    Fault

---- -------- ----------- ---- ---- ---- ------- --------

00-0 00(00)   Assigned    y    y    y    Passed  Normal

01-0 00(01)   Assigned    y    y    y    Passed  Normal

IO Devices:

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DID XSB       device  resource                usage