I have reached out to WD Customer Support and exhausted all troubleshooting suggestions with them. Since my device reached End of Support in 2013, there really isn’t anything more they can do. Maybe someone else has seen this issue and might be able to help! I’m pasting below all of the troubleshooting steps I performed based on my interactions with WD Customer Support.
Since I submitted my Incident, I have upgraded my iMac to macOS Big Sur version 11.3. And the issue remains the same.
There is no error to capture in a screen shot, because the device is not recognized at all. When connecting it to the iMac, it spins on, like it should, and the tiny light comes on, but nothing happens on the iMac to actually recognize the device.
I am including a screenshot of Disk Utility, where you can see that nothing appears for the device. You can that a different Western Digital device is connected correctly, it is a 3TB device that is formatted as 2 volumes, one for regular use, and one used specifically for Time Machine Backups. Please note that I have connected the 3TB device into the same USB port on this iMac as the one I have currently plugged the My Passport into, and the USB port functions correctly with the 3TB device.
The My Passport drive was accessible and functioning properly approximately 2 months ago on my old 2009 iMac running OS X El Capitan. I just recently tried to connect it to my new late 2020 iMac, and it will not connect, just like many others who I’ve read that are having the same connectivity issues since using macOS Big Sur.
There is no physical damage to the My Passport device. And as stated above, it connected properly to my old iMac. I have not tried another USB cable, because 1) it is a special cable that is needed to connect this My Passport device, and 2) it worked just fine with my old iMac.
I went through all of the steps that were possible in the article/link you provided. I will provide a response for each step listed in the article. 1) There is no power adapter, it gets its power from the USB cable connected to the iMac. 2) As stated above, I did not change out the cable because it is not a standard USB cable and the device worked fine on my old iMac. 3) I have tried multiple USB ports on my new iMac and the results are the same, and other devices function properly in each of those USB ports. 4) I turned off the iMac, let it restart, waited a full hour, and then retried connecting the device, and it still did not work. 5) As I already stated, it worked on my old iMac. I do not agree, that there is any issue with my new iMac, every other device, including a Western Digital 3TB device, all work correctly. I am not contacting Apple about this issue, this is a Western Digital My Passport issue. 6) Since it showed up correctly on my old iMac, the device has not failed.