Well, I don't know.
Did you try a second USB cable? A known good one?
Did the computer re-start? You fail to state what failed to restart. I'm assuming you meant MyDMX, but I could be wrong. Maybe your computer is dead, and that would explain a lot of things.
Why did the system black out and what do you consider a black-out?
Again, going by YOUR words:
A second computer was attempted(what, you tried to buy one and was declined?). I'm assuming you meant you installed MyDMX on it and then the interface was NOT recognized by the OS? Is that what you meant?
When the interface is plugged into the USB port, do you get the red power light? Are you BOOTING the computer first and then plugging the interface in? Are you running the latest MyDMX?
There are too many places to point the finger. It could be you had a power surge fry the computer and everything attached to it for all I know. I hope not.
Share more details.