Issues with Maxtor OT4 external hard drive

I have had this Maxtor One Touch 4 (OT4) since 2008 and haven't been able to use it since I lost my power cable at a freelance site in 2009. Now that I've finally found one, I want to get back to using it again for my "Time Machine" backup.

The main problem I have now is that I cannot access anything that may have been stored on the external. It's using 261.66 GB of its 698.51 GB capacity, with nothing showing in its contents. Are the files hidden?

Since I last used the external, I've upgraded my laptop OS to OSX 10.5.8, which is the last update available for this laptop technology. Can I still use the Maxtor for Time Machine, or should I go ahead and reformat it?

An old Maxtor drive from 2008 may not be suitable to use as a backup. Yes, I would go ahead and format it for use with Time Machine but you should not solely rely on that drive for a backup strategy.