I have a series one that we upgraded by adding a 2nd drive to, years ago. Recently the primary drive started making lots of noise and it has recently stopped functioning.

The 2nd hard drive had the software preloaded.

Can I just replace the original primary drive? I tried putting the secondary drive into another series one, but it doesn't acknowledge that it is there.

How do I get the unit to function? Do I need to replace the original primary drive? Will a new drive recognize the secondary drive?

Please help.