Greg,
Thanks for your help.
I doubt that the issue is power. I've successfully done this before with other disks. Plus, I can feel by touching the drive itself with my hand that the disk is spinning. Plus, see below ...
I went into the Device Manager, deleted the drive, and rebooted. The drive still doesn't show up under ThisPC.
I open Disk Management, and I'm told "You must initialize a disc before Logical Disk Manager can access it". I hit OK, and I get a pop-up that says "Data error (cyclic redundancy check)." This is a change from before the reboot. Prior to the reboot, the pop-up at this stage said "Incorrect function".
I run DiskPart and I select the disk and the volume. I then assign a letter to the volume. This works, insofar as a drive with that letter (I chose the letter Q) appears in ThisPC. However, when I open it from ThisPC, I'm told it's empty. The disk is definitely not empty, but perhaps I've created a new partition on the disk, and the new partition is empty.
More ideas?
Thanks again.
Paul