step one is to direct wire the cable to a tv (outside) to ensure CABLE from park is working
(to eliminate that the cable source is not the issue - don't ask me how I know that one !)
actually had a park guy bring a cheap black and white tv to do the same he one time I called them !!!
step two is to then run the cable inside to a direct wire to the tv
then set your tv to cable input and search for new stations... (to eliminate the cabling from the input hack thru the rv)
if that all works, then try thr cabling thru the rv...
if it still doesn't work, it's the cabling THRU the rv --- and good luck !!!
I'd let the dealer trace down another assembly line quality control issue...