I have an out of warranty 500 GB WD MyBook hard drive that sometimes does not mount, no matter what. And sometimes all of a sudden it will mount. Not good. I use it for backup and while data is not critical, it would be inconvenient to loose it.

I recently bought the Newer Technologies Voyager Q a SATA/SATA II. It's bare drive docking device. http://www.newertech.com/products/voyagerq.php With it I purchased two 1TB bare drives.

Upon one lucky and successful mounting attempt I backed up the problematic MyBook to a new bare drive.

Once the data was safely backed up I thought, what to do with the MyBook. I decided to open it up and pull the drive. I planned to try it in another external drive case. So I went on the internet and found out how to open the MyBook case (it's kind of like removing a bicycle tire). Once I got the drive out I discovered that it is a SATA drive. Interestingly it was wrapped in a foil cover that I removed. I slotted it into the Voyager Q, booted up my Mac and presto, immediate mounting of the drive. Confirmation that the issue was not the drive, but the SATA to USB/FireWire interface in the MyBook case. Now I still have an extra 500 GB and you can never have enough.