I'm going rapidly mad here!
I had a 1TB drive show up as not working in its Raid 0 array and it seems to have affected my 6TB Raid 1 Array which was working. I took these drives out and put in 2 new 3TB drives to set up as a Raid 1 array. These showed up as not working (although they work fine in Windows) - so I removed them thinking that that would show up as "not assigned" but they disappeared.
NOW no drives show up at all in the 2 data drive bays. The SSD on port 5 ( DVD connection) works fine and all drives work in Windows.
I cannot resolve the "invisibility" of all the drives in the drive bays? Any suggestions please? Thanks, Mel