So I took 4 of my external WD HDD apart today and installed them all in a ProBox 4 bay JBOD enclosure. After testing one and it passing fine, I installed the other 3. 750gb, 1500gb, 2TB and 3TB. However the 2 and 3 are coming up as 'uninitalized' or unreadable in 10.10. Plug them back into their own little USB adapter and voila. work perfectly. Apparently there is some hardware encryption going on. Since I am able to access the drives, is it possible to pull the MBR/partition table off it, and then re-insert it once its in the new enclosure so I dont have to write 5TB back on to the drive from my backup?