need some advise?

on my lowrance 334 c the split window went blank for the the gps side, it did show all the eastern lakes until it went blank, a lowrance rep told me to reset it by holding pages power button until a pop up was present,now the blank side of the gps shows the continent north america with a cursor or diamond.. but the sonar is ok still...hope I didn't erase my fishing hot spot card, I don't think I did since it was wacky before I reset it..can anyone tell me what to do....thanks for any info .. Randy