|are straps involved with these disks?|
If so, you may have to set them on *BOTH* disks.
I'm going to show my lack of knowledge and admit that I don't know what this means. I did a quick search and still couldn't figure it out. Please do elaborate on this or link to an explanation if you don't mind though, as maybe this will be the solution & I always want to learn.
Regarding the Linux boot, I did that and the drive shows up, but it hangs & I get an error when I try to access. After waiting for a long time, I can access a very limited amount of the drive but unlike the other drives it lists that one as "system reserved" - don't know what that means - it's looking like the HDD is likely bad - I think I'm giving up on Western Digital - 2nd HDD failure in 2 years!
Thanks for all the help on this so far!