I inherited a Pegasus R4 Promise Technology 4 disk Raid box. I DON'T NEED TO RECOVER ANY DATA. One drive is dead. I would ultimately like to find the dead drive, remove it, and wipe the remaining drives to start over with a 3 x 1TB raid. When i first connected it it only showed a 3TB capacity. After powering down and removing drives one at a time (Probably shouldn't have done this but since I don't need the data I figured I'd at least be able to format it in Disk Util) to try and find the dead drive, Yosemite no longer recognizes the Raid in Disk Util. I've tried both thunderbolt ports. One of the active drives is corrupted and has a Red light displaying which I suspect is keeping OSX from recognizing it. And I'm sure is a result of removing a drive that was used in the Raid. (shame on me... got it) Any suggestions on how to: 1. Wipe the drives 2. Find out which one is dead Should I just remove them from the Pegasus box and try to format them one at a time with a hard drive dock? Thanks for any help!