There's isn't a real need to disconnect the wires. Pull out the gfi outlet, so you can access the back side. Put a simple tester, no need for a fancy fluke, to the two wires coming into the GFI outlet. Then take the tester on the hot and natural wires going out. If there's power, then is the outlet down stream. I bet you there's no power on the output side. If you have no tester, they run about 15 bucks for a very simple one, just buy a new GFI and swap out the old. I bet there's your problem if not, tighten wire nuts, or clamp screws on the GFI or other outlets. I have had wire nuts come loose on me causing intermittent connection. Please shut off the breaker on the main panel to that circuit before you monkey with it. You do not look good with curly hair BTW.
