You may also want to check that the GFI outlet is good. When they go bad, they tend to cause other things to not work. On our trailer, the GFI outlet in the bathroom shuts down the entire trailer. And since the factory installed GFI's are low bid items, they tend to go bad frequently.
If you push the reset button and it pops off again promptly, that is a good indicator that the GFI is bad. Get a replacement at Lowes, Home Depot or and hardware store. Make sure you get the same amp rating as the one that is bad, typically 20 amp.