WD ShareSpace status "degraded" but no drives bad

My 4TB WD ShareSpace gives me a status of “degraded” but no drives are marked as bad or failed, either in the user interface or in the front panel lights.

How do I tell which drive is bad so I can replace it?

Version Info:

2.3.01 with MioNet 4.3.1.12     

You can take the hard drives one by one and run a test using DLG on a PC. Check the link below for the steps.

http://wdc.custhelp.com/app/answers/detail/a_id/940.

Power cycling the device triggered the drive display on its front to display the bad drive (the associated light went from green to amber).

Kudos to WD support for the help.