LS441D trouble adding discs

[henkbis]

Hi, I am having problems when adding discs to my LS441D.

I have 2 x 4Tb discs which were pretty full (no raid) so I wanted to add 2 more discs (exactly same type as other 2).

However when I mount an extra disc (either of the 2) in the cabinet, all three discs show up as "failed".
When I remove the new disc, the old 2 are fine again (happily).

When I temporarely remove the 2 old ones, the new one shows up as "unformatted".
I can format it, but when I shutdown, add the 2 old ones and start, I have 3 "failed" discs again ....
when I do checkdisc (only with the new one, since the other 2 contain data) "failed" becomes "unformatted", I can format it,
but when I have all 3 discs in the cabinet and reboot all 3 are "failed" again...

Already applied latest firmware, that did not help ...

Anybody any ideas?
Thanks...

[henkbis]

Just found the solution:

forgot that the 2 new disks were for a short time in another NAS, so there were already partions on them ...

Have these removed on my PC using diskpart commando clean
(see http://buffalotech.com/support-and-downloads/faqs/cleaning-a-disk-in-windows-7-using-diskpart.exe)

When now placed in the LS alongside the other 2 disks, the new disks do appear without problems and can be formatted...

phew....