I have a 1989 SeaRay 280DA.
While plugged into a 110v source at my house, I plugged a battery charger into one of the boat’s 110 AC outlets. The battery charger shorted out, after that I cannot get power to any of the 110 ac outlets on board.
I have checked all the breakers in the main panel, and even replaced all of the AC outlets on board without success. I have checked out the on board battery charger and it is working fine.
I would start at the source of power and make you way through the boat. If there is a bad connection, it may have voltage with a meter but not enough current to allow the device to work. When you are carefully working your way through the system, try turning devices off and on while testing with a meter to determine where the problem is.
If you have power at the source (the outlet on your house), you should be able to logically trace it through the system. It could be something as simple as a bad connection in your shore power cord causing all of the problems.
Hope this helps,