 Ok, this is now resolved.  Quite embarrassing actually.  I screwed the HDD back into the chassis in the incorrect slot... there are screw holes marked SATA and SAS, I put it in the SATA slots (it's a SAS disk), so the HDD was slightly too far away to make a connection!  Doh!! Thanks for your help - feel a bit stupid now, but you live and learn eh
I have a RAID 5 array (virtual disk) which consists of 4 seperate HDDs.  One of them has failed (orange light continuously flashing), so I have purchased a new HDD, and placed it into the slot expecteing it to rebuild automatically.... - but after sometime, there is no flashing lights at all, - it seems completely dead. I have installed Open Manage Server Administrator, on the Storage Dashboard, it shows the status of "Virtual Disk 1" as "Degraded". If I then click into the "Virtual Disk 1" Properties, it only presents me with three disks, which all have a green-tick status.  Can anyone advise me on how to add the fourth disk?  Many thanks in advance for any help
Poweredge R710 - failed HDD