I don't know if you posted this elsewhere or not but a suggestion was to make sure all the electrical screws are tight,
I have even seen loose screws on the shore power cord (Outlet came off in my hand)
Mind you these are problems I have personally seen and I am not a professional RV tech.. That is just my rig or my next site neighbor's. (His was the outlet end, thankfully he was an electrical engineer so between my tool box and his mind all fixed).
Home is where I park it!