Drobo Pro won't start

I am using DroboPro with a mac mini as server. I recently need to restart Drobo because it seems to be hung in the relay out. I found when I started the Drobo, after several seconds, the power light turns solid green while others are not lit. but then it stays in that state seems forever ( already 30min ). I can hear the fans are on but no further activity. Any thoughts on what happened ? And how to solve that ?

Thank you

Can you also try to boot up the pro without drives and see if dashboard detects the unit? I think you’ll need to file a support ticket to drobo with a log file…

Thank you so much. The problem is actually solved. I just keep Drobo under off state for longer time ( around 1hr ) before restart. I guess the first start did not really give a reboot and the machine was still hung in some state.