Replacing Disk Drive of RAID - stays degraded!

One of 2TB drives reported bad sectors, degraded.  I removed it and replaced with an identical drive from a second (spare) MyBookWorld White.  When I replaced it, GUI reported it as “foreign” – didn’t see that in notes.  There was an icon to “clean” the drive.  OK… did that.  But it will NOT bring the drive back into RAID1 - been a week now.  GUI reports drive as “unassigned” and “new.”

SSH in, and “cat /proc/mdstat” shows only the one drive up to date.

HOW do I get this box to bring the RAID1 volume back from degraded?  Thanks - John

I am surprised WD doesn’t monitor and answer questions… ?  I don’t want to hack this box TOOOO much!

I gave up and xferred files to the box that WOULD bring up RAID1 on the new disk drive, using rsync. 

I’ve got exactly the same problem.   WD support have suggested a couple of things (resetting the unit and also zero writing the disk)  joy.

I’m chasing them again today to provide me with further assistance.