Could my ex2 only reading from one bay?

Hi. MyCloud Ex2 has been working fine for several years. One of the blue LEDs on the front is not lit up…I added a new, WD red hard drive to that bay to no avail. I then switched the hard drives between the bays. Still only one HD led lit up. I removed the hard drive from the bay with the unlit LED and tested it using WD Data Lifeguard. The drive passed all the tests.

Could the EX2 itself have failed on that one bay? Thanks