How to Erase External USB Drive Which Won't Mount & Isn't Recognized Before starting, let me mention that I have ALREADY read the following thread in its entirety, and it did not help my situation:

https://discussions.apple.com/thread/4832305?start=0&amp;tstart=0

I have also read four related posts here on apple.stackexchange.com, and they haven't helped either.

Now to my situation . . .

I have an external USB 2 TB eGo Drive. For several years, the drive has served as my primary backup.

Then, a few months ago, it suddenly stopped mounting on my desktop. My other external USB drive, a Western Digital, continues to mount just fine.

Unplugging the eGo Drive's power supply and plugging it back in again several times, unplugging the USB cable from both the drive and my iMac, and using a different USB port on my iMac, have not solved the problem. The eGo Drive still refuses to mount.

Furthermore, it does not show up in the left pane of Disk Utility.

Neither is it listed under About This Mac/System Report/Hardware/USB.

It likewise refuses to appear if I type "/volumes" under "Go/Go to Folder...".

It does not appear in the EtreCheck app either.

Finally, if I type "diskutil list" in the Terminal, that doesn't work either.

Another suggestion I found online said to force quit the "fsck_hfs" process if I see it in Activity Monitor. However, I do not see it there, not even under "All Processes".

When I turn on the eGo Drive, I can hear it spinning up, but that is as far as it goes.

I read online that there is an application called USB Prober -- a part of Xcode -- which may possibly recognize the eGo Drive and get it to mount. However, I do not see it anywhere in my Xcode 7.0 installation, and I haven't found a link to download it from either.

I would really like to resurrect the eGo Drive if there is still some way to do it. If not, then I face another problem: The eGo Drive is loaded with a lot of personal data, including family photos and movies, financial records, software registrations and serial numbers, and a lot more. As such, I obviously do not feel comfortable with just throwing it i the trash.

So, is there some easy way to totally erase the drive, even though I am unable to mount it on my desktop? I have read that strong magnetic fields can destroy data on a hard drive, and I imagine that they sell devices which perform just such a task, but I don't own one of them, and I probably couldn't afford one anyway.

So, if anyone can tell me how I can either get my iMac to recognize the eGo Drive so that I can at least erase it -- and maybe even reformat it if need be -- or possibly even mount it, and then reformat it, I would be very appreciative.

Thank you.
There's still several elements you may not have checked. First, swap cables to make sure the cable is ok. If it still fails, then next, make sure your power supply really works. If possible, get a variable replacement AC/DC converter from an electronics store. Mine lets me set the voltage, amps, and ohms along with changing the connector tips. Use the settings on the original DC converter to test. 

Assuming none of those items were the issue then you still have two other elements to check: the case and its controller and the drive itself. 

To check the case: go to your local Best Buy or other electronics store and get a hard drive case. They're very inexpensive now. Pop open the old case, take the drive out, and put it into the new case. If it mounts, the issue was the case. If it still does not mount, it's the drive.

To really get rid of the drive, toss the drive in a fire. Nothing will be salvageable.