I determined that the enclosure’s controller board is indeed “partly” fried. I used the enclosure with another system and it caused the system to freeze but no POST issues. This would have been a PAIN to discover.
The drive survived though despite some slight data corruption. I lost my Virtual Server 2005 R2 install from the backup as there were too many corrupted files. I simply restored it as is and uninstalled it and then reinstalled it, I did not lose any virtual machines is what was important.
The blitzed drive needed to undergo a 3.5hr long nail biting chkdsk though…
Overall, my 4GB system has been happily recovered and I only lost an external drive enclosure as casualty.
Theoretically, I could take the controller board to an electronics repair shop nearby and it would likely be a relatively inexpensive repair. I may yet go that route…
Lesson learned, check the devices for power requirements and check the adapters for power output!