WOW - you folks are communicating way over my head !
Wish I had all your knowledge.
If no power than it's probably the hard drive controller is bad... At this point you won't be able to mount the drive and pull any data without it registering. Only other way to get the data recover is the professional way, which a professional will open the drive in a vacuum enclosure and moving the hard disk to rebuild it in a working controller. At this point it isn't worth trying to have professional like "Disk Doctor" recover the data as it'll be very expensive.
WOW - you folks are communicating way over my head !
Wish I had all your knowledge.
When there is no power which has a fan in the back of tower case. check the power supply fan is on or not. If no fan, that means power supply. Just my 2 cents from my first career in 1995 that im way out dated.
Everything else runs fine, just that HDD is gone. Even tried another HDD externally so its not even the external connection. I have 4 HDDs in this machine, the main one goes out....go figure right LOL. At least it wasn't my boot drive...
-Matt