When I had my new windows installed by Andersen, they managed to somehow cause a circuit to stop working. That circuit turned out to have a LOT of stuff on it — most of the outlets in the garage, the garage door opener, the upstairs bathroom GFI, the east porch outlet (which is how the shed gets its power), etc, etc. I searched for a tripped GFI but couldn’t find one. So I decided to take a day to document where every circuit went and label every outlet in the house.
This gadget, a Klein Tools ET300, made the job a lot faster. You plug in the transmitter to an outlet and then go back to the breaker panel and can immediately find which circuit that outlet is connected to. Much faster than turning off breakers and searching for dead outlets!
Anyway, it turned out there are multiple GFIs on that dead circuit, and I had failed to find one of the GFIs — which was in the garage. That one was tripped. Resetting it made everything work again.