Bruce,
I started my career in IT working at a PC repair shop (and sometimes do this on the side for businesses). Whenever a customer mentioned a drive stopped working, or started running really slow, or something that indicated a failed or failing drive I always had two recommendations:
* Stop using the PC
* Image the drive immediately, or bring the drive in and let us attempt to image it.
What ends up happening is you have a finite number of reads left, so all of the experiments should be done on a image instead of the physical drive.
Sometimes its heat-related, and putting the drive in a anti-static bag and putting it in the fridge helps.
In your case, if the drive is already not responding or showing any files, you pretty much have two choices:
1 - Attempt to swap the controller board on the back of your drive (sometimes you have to swap a SPI Flash chip containing the drive-specific information/metadata you need, sometimes that information is in the controller itself, and you're out of luck)
2 - Send the drive off to ontrak or some reputable company. A reputable company will actually disassemble your platters and recover the data if they have to, but it's typically at least $10k (i'm sure it's more than that now).
I have about a 2/5 success rate on 1. One drive did work when cold, but stopped working when it heated up. I put it under a fan and let it do its thing, and managed to image the entire drive after 3 days, and saved a guy about $50k worth of construction fees, because he couldn't otherwise prove the building was built to some specification.
Good luck!
You might want to try my "PC repair shop alma mater" PC Quest in Middletown as a first stop, but based on what your email had specified, i'd just weigh out cost/benefit on option 2.
Britt