[jimcol]

Something similar happened to a fellow MOC'er during a Branson Rally back in 2006. He was sitting in the unit when it happened. He remembered the ceiling run going to a very high speed before all the electronics fried. It ended up being an open neutral. I'd start at your electrical panel in the 5'er and check all connections for tightness. Work your way back to the pedestal including the lugs on your 50amp receptacle and your power cord.
After seeing what he experienced I try to make this part of my annual maintenance.
Going back to the 06 incident he was really lucky. 5'er was still under warranty and the dealer/manufacturer covered everything within a couple of days. Don't hear of warranty work like that anymore.