external drive not showing up

[kentucky]

my external drive is not showing up on my screen anywhere.
it has been working fine.
could it be a permisssions issue.
mac g4, tiger 10.4.9.

all my backup files are on there and i need access today.
help please. i tried to view on another mac and it's not showing up there either.

 

[jmgalvin]

I noticed RAID. is that set right and have you downloaded any Apple updates lately and installed them while the drives were connected? If so try disconecting the drive and then plugging it back in.

Using OSX 10.3.9 on a G4