Lawson, a couple of weeks ago I had the same problem. I was really hot under the collar over it and even called the previous home owner who built and wired this place to ask if he had stashed a secret panel somewhere. Having eliminated that possiblity along with snapping all the circuit breakers (including the main) on and off a couple of times, I finally called an electrician to set up a "visit".
This guy was outstanding! He said to go look at the GFI outlet in the shop and push those test/reset buttons. He also made a passing comment, to "be sure to move any boxes stacked up against the wall and look for any GFI's that may be "hidden".
What the heck! Was this guy ever in my shop? No! How did he know about my stacks of boxes against the walls?
Well anyway, I followed his directions after first checking the home interior GFI's to no avail. I don't learn too quickly see?
So after walking back outdoors frustrated from checking the shop, I looked back and noticed that one last box that was still against the wall. Now who the hell ever puts TWO GFI's in one shop on 110v?
Well apparently the guy who built this place did! There neatly concealed was yet a second GFI. When I hit those two buttons to check it, things came to life!!
WHOOOODA THUNK IT?
So Lawson, do you have a second GFI in your shop? Maybe this guy built your place too.
Good luck!