There is only one GFCI in my 142CK. I would start looking at the connections. When I was adding an outlet for a Blu-ray player the one I connected to barely had the wires in the knife blade connectors. It was only a matter of time before one of the wires would have come out. There are also times where the knife blade doesn't penetrate the insulation. I replaced all of my outlets where I had room to add a box with household screw terminal outlets.
2015 F150 Ecoboost
2014 Palomini 142 CK