caravan electrics

We have just become the proud owners of a 2009 Fleetwood Heritage 640EB(t) and had our first trip out at the weekend. We have been unable to make the plug socket at the front of the caravan where you plug in the tv and also the same at the rear of the caravan work although the one next to the kitchen sink works. Also the microwave will not work. Are we missing something to do with the 12 volt supply although I thought the inverter dealt with this when you are plugged into an electric hook up. Any help would be gratefully accepted. Thanks Sue