My MyCloudEX2 is showing solid red power LED light, no light on Bay 1, and solid blue on Bay 2. The device itself is 5+ years old. Switching drives back and forth does not seem to resolve the matter.
How to confirm if the device is finished?
On a related point, very recently switched to Mac computers - how to connect to drive dashboard?
The power and disk LEDs frequently burn out so I wouldn’t worry too much about the drive 1 led being dead. Have you done a 10 second or 40 second reset? You can’t just swap drives back and forth unless you are doing a completely new setup.