Dear Apple Support Community,
I have an early-2008 MacBook, running OS X Lion (10.7.5). I also have some assorted external hard drives for data backup. One of them is an older WD 500GB external HD that I purchased in 2007. It has been running fine up until yesterday. It was connected to my Mac, when I received the pop-up message that my Mac couldn't repair the disk and that I should back up my data and reformat the drive. I disconnected the external HD from my Mac, and bought a brand-new WD My Passport for Mac 1TB external HD to use to backup my old 500GB external hard drive.
This morning, I connected the old external HD and the new external HD to my Mac to start the backup, but only the new external HD showed up in Finder. The old external HD makes noises like it is booting up and functioning, but won't show up on my computer. I tried connecting the old external HD to each of the two USB ports on my Mac (in case it was a problem with the computer's USB port) and it still wouldn't show. I relaunched Finder, it still wouldn't show. I rebooted the Mac, it still wouldn't show. I turned the old external HD on and off a few times, still wouldn't show up. When I launch Disk Utility, it shows the drive but it is grayed out and says it is unmounted. I tried mounting the external HD to my husband's MacBook Pro, and it wouldn't show up there, either. I have connected each of my other external drives to my Mac, and they show up in Finder without any trouble, which leads me to believe that the problem is just the external HD, not my Mac.
My question is: is there any way to still retrieve the data from my old external HD, or am I out of luck?
Thank you in advance for your assistance.