It is possible that your USB bridge has failed, though it seems more likely that the issues is with the hard drive inside. It is the card that allows the SATA hard drive inside the computer to connect to your USB port. However, it also encrypts the data as it flows through the card, making it more difficult to access the data.
If your data is important to you, I suggest you contact a professional data recovery lab before you attempt anything further. A few labs I recommend are:
Recovery Force
Data-Medics
PCImage
If you've ruled out using a professional data recovery lab, you may want to try one of the following procedures:
- try different USB cable and/or power cable (make sure the power is the same)
- try a different USB bridge from an identical drive (make sure the p/n o the USB bridge inside the case is the same)
- although the data will be encrypted at this point, you can try to connect the hard drive directly to a computer with SATA or another generic USB bridge to see if the drive detects correctly
My guess is this is an issue that is not a DIY case, but could very likely be a simple, sub $500 recovery by a reputable data recovery lab.