Drobo disappeared from Desktop, won't reconnect, shuts down

I was rendering video from FCPX to the 5D on a new Mac Pro when it suddenly disappeared from the desktop. Dashboard didn’t see it. I restarted it, and it went into a boot loop. I followed directions here:


And was left with a Drobo that won’t boot at all now. It goes through a boot sequence, and then apparently shuts down (though the fan is still running). Dashboard of course will not recognize the Drobo.

Here is a video of the boot sequence:


I tried a different Thunderbolt cable and the USB 3 cable, with no change. I also tried two other computers.

Firmware and Dashboard are both up-to-date.

If I remove all the drives, the Drobo boots normally to the single red drive light, and Dashboard recognizes it.