Dead Disc

I have a ReadyNAS Pro 6
The Seagate 2TB disc in Drive bay 5 has failed and reported as Dead Disk in Frontview.
I Hot replaced it with WDC WD30EFRX
After half hour nothing has happened. The disc doesn't seem to being recognised.

These are the Volume Settings
Ch 1 : WDC WD30EFRX-68EUZN0 [2794 GB] 1858 GB allocated
Ch 2 : WDC WD30EFRX-68EUZN0 [2794 GB] 1858 GB allocated
Ch 3 : WDC WD1003FBYX-01Y7B0 [931 GB] 927 GB allocated
Ch 4 : Hitachi HUA722020ALA330 [1863 GB]1858 GB allocated
Ch 5 : Seagate ST32000542AS [1863 GB]
Ch 6 : Seagate ST32000542AS [1863 GB] 1858 GB allocated

This is the Health Printout
Device Description Status
Disk 1 WDC WD30EFRX-68EUZN0 2794 GB , 39 C / 102 F , Write-cache ON OK
Disk 2 WDC WD30EFRX-68EUZN0 2794 GB , 41 C / 105 F , Write-cache ON OK
Disk 3 WDC WD1003FBYX-01Y7B0 931 GB , 43 C / 109 F , Write-cache ON OK
Disk 4 Hitachi HUA722020ALA330 1863 GB , 42 C / 107 F , Write-cache ON OK
Disk 5 Seagate ST32000542AS 1863 GB , 1 C / 33 F Dead
Disk 6 Seagate ST32000542AS 1863 GB , 38 C / 100 F , Write-cache ON OK

Should I restart the ReadyNAS or how do I force the new disc to synch

Thanks