I would inspect the wiring around the tongue. I would say it is possible some road debris damaged the wiring.
Check the ground connections on the TV and trailer along with the trailer/TV connector. He may want to open up the trailer connector and look for wires that have pulled out of the connection. This pertains to non-molded connector.
Bud
USAF Retired
Pace Arrow
2003 Chev Ice Road Tracker