My Book for Mac Problem

I have a My Book for Mac and I use it on a Mac Mini running Mavericks.  Never had any problems with this MB.  I upgraded the firmware and now the MB turns on but will not mount and will shut off immediately. 

Did anyone experience this behavior?

Hello,

Can you please provide the model number of your drive.

I haven’t seen this case with a USB drive on a Mac. 

Have you tried resetting the unit. 

Is the drive showing on the disk utilities.