I would think so, but you are welcome to try a soft reboot to see if they come back online but do not be surprised if they do not.. After doing that then the diagnostics might give a clue as to the drive state as they may then have SATA information for the problem drives. You could also try doing an extended SMART test on the 2 drives, if they passes without error I would be looking into the power/sata cabling as possible culprits.