I have an OWC Thunderbolt 2 dock that I damaged after unwittingly installing a Firewire 800 cable in upside down...

I have found the steps given in the link below have resolved issues a few times now when I run into a disk that fails to mount in High Sierra. https://mycyberuniverse.com/web/how-fix-mediakit-reports-not-enough-space-on-device.html First time I ran into this issue, it was with a brand new WD Elements HD. I think I eventually found the correct information on Western Digital's website, (which is referenced in the link provided). I ran into this issue again this evening with an old APPLE (Maxtor) hard drive from an old eMac... Seriously Apple - fix your tools... one shouldn't have to find "obscure" terminal commands to do something that DiskUtil should be addressing, particularly if erasing or reformatting a drive... Note that this fix is one to try after other steps (restarting, single user mode disk check, etc.) if the drive has data on it that you need. In my case, I was not concerned with retaining any data from the disks involved.

This connector is actually a "locking" connector - the small slot in the middle of the jack (visible in the picture) is where a protrusion on the plug actually "locks" the plug in place. One may need to use a small / thin flat blade screwdriver inserted against the top of the plug to gently pry the jack housing up while at the same time pushing the plug down and sliding the plug out. I realized this after breaking the plug following the listed instructions...

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Better yet - this step and step 30 should really just be eliminated - there isn't any reason to unplug the sensor - its not in the way of changing out the processor.