External case change and cannot see my files

I have a Toshiba 1.5TB External HD, I could not find a power supply for it soI did the next best thing and transferred it into a Samsung 3G case. I can get into the drive, the Properties show that -500gigs is utilised, but I cannot see any files. How do I access the drive and be able to see my files?

Has anyone had this problem, and know how to solve it?