Try GetDataBack (NTFS or FAT).
it could be a missing file system file for whatever reason or a physical problem with the USB Controller.
I had a USB 2.0 Drive that worked on my PC, but on other PCs in the house it did exactly what you're seeing.
HAF922, 700W OCZ, ASRock Fata1ity 990FX Pro,
Corsair H100,AMD FX8350 @ 5.15GHz, 16GB G.SKILL Sniper@DDR2133,
Sapphire DualX HD7950-OC@1.1 GHz Core/6GHz Mem, Creative XFi Fata1ity Platinum Champ.,
ASUS VS248HP 24" LEDx3, 5760x1080(6048x), Turtle Beach Earforce, RCA 5.1 Surround
CH Fighterstick, Pro Throttle, Pro Pedals, Saitek EclipseII
IntensityPro 10-Bit, Kinect For Windows, TrackIR 4 Pro
WD 1.5TB Black SATA3, SG 1TB SATA2, 2x SG 500GB SATA2, 1x SG Ext. 1TB USB3