I have a WD black caviar internal drive that I have put into an external enclosure with USB 3.0. My PC and Mac will show that it is connected but not recognized. I am unable to access the drive on either machine. If I do connect it directly to my PC motherboard via SATA it works fine. Not sure what the issue could be.
Your enclosure contains a USB-SATA bridge board. It is connected as follows:
computer's USB port <-- USB cable --> bridge board <-- SATA cable --> hard drive
The bridge board will appear in Device Manager as a USB Mass Storage Device.
The hard drive should appear in Disk Management. However, if there is a communication problem between the bridge and the HDD, then there will be nothing in Disk Management. In this case try installing the drive's OPT1 jumper to reduce the SATA link speed.
If the drive does appear in Disk Management, but its capacity is reported as 1/8th of its full factory capacity, then it will be because the bridge firmware is configured with a 4KB sector size rather than 512 bytes.
How do UVCView and HD Sentinel identify the drive? UVCView talks to the USB-SATA bridge IC inside the enclosure whereas HD Sentinel attempts to communicate with the HDD behind the bridge.